Menu
Home Explore People Places Arts History Plants & Animals Science Life & Culture Technology
On this page
Hummingbird
Family of birds

Hummingbirds are birds native to the Americas, belonging to the family Trochilidae with around 366 species across 113 genera. They range from Alaska to Tierra del Fuego, mainly in Central and South America. Known for their rapid, agile flight and the humming sound from fast-beating wings, they exhibit remarkable metabolic capacity and diverse plumage. The smallest species is the bee hummingbird, while the giant hummingbird is the largest. Specialized for feeding on nectar, they also consume insects. Some, like the rufous hummingbird, perform long migrations, notably between Alaska and Mexico. As of 2024, 21 species are endangered or critically endangered.

Related Image Collections Add Image
Profiles
1 Image
We don't have any YouTube videos related to Hummingbird yet.
We don't have any PDF documents related to Hummingbird yet.
We don't have any Books related to Hummingbird yet.

Description

Hummingbirds are the smallest known and smallest living avian theropod dinosaurs.121314 The iridescent colors and highly specialized feathers of many species (mainly in males) give some hummingbirds exotic common names, such as sun gem, fairy, woodstar, sapphire or sylph.15

Morphology

Across the estimated 366 species, hummingbird weights range from as small as 2.0 grams (0.071 oz) to as large as 20 grams (0.71 oz).1617 They have characteristic long, narrow beaks (bills) which may be straight (of varying lengths) or highly curved.1819 The bee hummingbird – only 6 centimetres (2.4 in) long and weighing about 2 grams (0.071 oz) – is the world's smallest bird and smallest warm-blooded vertebrate.2021

Hummingbirds have compact bodies with relatively long, bladelike wings having anatomical structure enabling helicopter-like flight in any direction, including the ability to hover.2223 Particularly while hovering, the wing beats produce the humming sounds, which function to alert other birds.24 In some species, the tail feathers produce sounds used by males during courtship flying.2526 One species of hummingbird – the little woodstar (Chaetocercus bombus) – has a wing-beat frequency of 99 per second during hovering.27 Such extreme flight demands are supported by a high metabolic rate dependent on foraging for sugars from flower nectar.2829

Hummingbird legs are short with feet having three toes pointing forward and one backward – the hallux.3031 The toes of hummingbirds are formed as claws with ridged inner surfaces to aid gripping onto flower stems or petals.32 Hummingbirds do not walk on the ground or hop like most birds, but rather shuffle laterally and use their feet to grip while perching, preening feathers, or nest-building (by females), and during fights to grab feathers of opponents.3334

Hummingbirds apply their legs as pistons for generating thrust upon taking flight, although the shortness of their legs provides about 20% less propulsion than assessed in other birds.35 During flight, hummingbird feet are tucked up under the body, enabling optimal aerodynamics and maneuverability.36

Of those species that have been measured during flight, the top flight speeds of hummingbirds exceed 15 m/s (54 km/h; 34 mph).37 During courtship, some male species dive from 30 metres (100 ft) of height above a female at speeds around 23 m/s (83 km/h; 51 mph).3839

The sexes differ in feather coloration, with males having distinct brilliance and ornamentation of head, neck, wing, and breast feathers.4041 The most typical feather ornament in males is the gorget – a bib-like iridescent neck-feather patch that changes brilliance with the viewing angle to attract females and warn male competitors away from territory.42

Life cycle

Hummingbirds begin mating when they are a year old.43 Sex occurs over 3–5 seconds when the male joins its cloaca with the female's, passing sperm to fertilize the female's eggs.44

Hummingbird females build a nest resembling a small cup about 1.5 inches (3.8 cm) in diameter, commonly attached to a tree branch using spider webs, lichens, moss, and loose strings of plant fibers (image).4546 Typically, two pea-shaped white eggs (image) – the smallest of any bird – are incubated over 2–3 weeks in breeding season.4748 Fed by regurgitation only from the mother, the chicks fledge about 3 weeks after hatching.4950

The average lifespan of a ruby-throated hummingbird is estimated to be 3–5 years, with most deaths occurring in yearlings,51 although one banded ruby-throated hummingbird lived for 9 years and 2 months.52 Bee hummingbirds live 7–10 years.53

Population estimates and threatened species

Although most hummingbird species live in remote habitats where their population numbers are difficult to assess, population studies in the United States and Canada indicate that the ruby-throated hummingbird numbers are around 34 million, rufous hummingbirds are around 19 million, black-chinned, Anna's, and broad-tailed hummingbirds are about 8 million each, calliopes at 4 million, and Costa's and Allen's hummingbirds are around 2 million each.54 Several species exist only in the thousands or hundreds.55

According to the International Union for Conservation of Nature Red List of Threatened Species in 2024, 8 hummingbird species are classified as critically endangered, 13 are endangered, 13 are vulnerable, and 20 species are near-threatened.56 Two species – the Brace's emerald (Riccordia bracei) and Caribbean emerald (Riccordia elegans) – have been declared extinct.57

Of the 15 species of North American hummingbirds that inhabit the United States and Canada,58 several have changed their range of distribution, while others showed declines in numbers since the 1970s,5960 including in 2023 with dozens of hummingbird species in decline. As of the 21st century, rufous, Costa's, calliope, broad-tailed, and Allen's hummingbirds are in significant decline, some losing as much as 67% of their numbers since 1970 at nearly double the rate of population loss over the previous 50 years.616263 The ruby-throated hummingbird population – the most populous North American hummingbird – decreased by 17% over the early 21st century.64 Habitat loss, glass collisions, cat predation, pesticides, and possibly climate change affecting food availability, migration signals, and breeding are factors that may contribute to declining hummingbird numbers.6566 By contrast, Anna's hummingbirds had large population growth at an accelerating rate since 2010,67 and expanded their range northward to reside year-round in cold winter climates.68

Superficially similar species

Some species of sunbirds — an Old World group restricted in distribution to Eurasia, Africa, and Australia — resemble hummingbirds in appearance and behavior,69 but are not related to hummingbirds, as their resemblance is due to convergent evolution.70

The hummingbird moth has flying and feeding characteristics similar to those of a hummingbird.71 Hummingbirds may be mistaken for hummingbird hawk-moths, which are large, flying insects with hovering capabilities, and exist only in Eurasia.72

Range

See also: List of Apodiformes by population

Hummingbirds are restricted to the Americas from south central Alaska to Tierra del Fuego, including the Caribbean. The majority of species occur in tropical and subtropical Central and South America, but several species also breed in temperate climates and some hillstars occur even in alpine Andean highlands at altitudes up to 5,200 m (17,100 ft).73

The greatest species richness is in humid tropical and subtropical forests of the northern Andes and adjacent foothills, but the number of species found in the Atlantic Forest, Central America or southern Mexico also far exceeds the number found in southern South America, the Caribbean islands, the United States, and Canada. While fewer than 25 different species of hummingbirds have been recorded from the United States and fewer than 10 from Canada and Chile each,74 Colombia alone has more than 16075 and the comparably small Ecuador has about 130 species.76

Taxonomy and systematics

Further information: List of hummingbird species

The family Trochilidae was introduced in 1825 by Irish zoologist Nicholas Aylward Vigors with Trochilus as the type genus.7778 In traditional taxonomy, hummingbirds are placed in the order Apodiformes, which also contains the swifts, but some taxonomists have separated them into their own order, the Trochiliformes.79

Hummingbird wing bones are hollow and fragile, making fossilization difficult and leaving their evolutionary history poorly documented. Though scientists theorize that hummingbirds originated in South America, where species diversity is greatest, possible ancestors of extant hummingbirds may have lived in parts of Europe and what is southern Russia today.80

As of 2023, 366 hummingbird species have been identified.81 They have been traditionally divided into two subfamilies: the hermits (Phaethornithinae) and the typical hummingbirds (Trochilinae, including all the other species). Molecular phylogenetic studies have shown, though, that the hermits are sister to the topazes and jacobins, making the former definition of Trochilinae not monophyletic. The hummingbirds form nine major clades: the topazes and jacobins, the hermits, the mangoes, the coquettes, the brilliants, the giant hummingbird (Patagona gigas), the mountaingems, the bees, and the emeralds.82 The topazes and jacobins combined have the oldest split with the rest of the hummingbirds. The hummingbird family has the third-greatest number of species of any bird family (after the tyrant flycatchers and the tanagers).8384

Fossil hummingbirds are known from the Pleistocene of Brazil and the Bahamas, but neither has yet been scientifically described, and fossils and subfossils of a few extant species are known. Until recently, older fossils had not been securely identifiable as those of hummingbirds.

In 2004, Gerald Mayr identified two 30-million-year-old hummingbird fossils. The fossils of this primitive hummingbird species, named Eurotrochilus inexpectatus ("unexpected European hummingbird"), had been sitting in a museum drawer in Stuttgart; they had been unearthed in a clay pit at Wiesloch–Frauenweiler, south of Heidelberg, Germany, and, because hummingbirds were assumed to have never occurred outside the Americas, were not recognized to be hummingbirds until Mayr took a closer look at them.8586

Fossils of birds not clearly assignable to either hummingbirds or a related extinct family, the Jungornithidae, have been found at the Messel pit and in the Caucasus, dating from 35 to 40 million years ago; this indicates that the split between these two lineages indeed occurred around that time. The areas where these early fossils have been found had a climate quite similar to that of the northern Caribbean or southernmost China during that time. The biggest remaining mystery at present is what happened to hummingbirds in the roughly 25 million years between the primitive Eurotrochilus and the modern fossils. The astounding morphological adaptations, the decrease in size, and the dispersal to the Americas and extinction in Eurasia all occurred during this timespan. DNA–DNA hybridization results suggest that the main radiation of South American hummingbirds took place at least partly in the Miocene, some 12 to 13 million years ago, during the uplifting of the northern Andes.87

In 2013, a 50-million-year-old bird fossil unearthed in Wyoming was found to be a predecessor to hummingbirds and swifts before the groups diverged.88

Evolution

Hummingbirds split from other members of Apodiformes, the insectivorous swifts (family Apodidae) and treeswifts (family Hemiprocnidae), about 42 million years ago, probably in Eurasia.89 Despite their current New World distribution, the earliest species of hummingbird occurred in the early Oligocene (Rupelian about 34–28 million years ago) of Europe, belonging to the genus Eurotrochilus, having similar morphology to modern hummingbirds.909192

Phylogeny

A phylogenetic tree unequivocally indicates that modern hummingbirds originated in South America, with the last common ancestor of all living hummingbirds living around 22 million years ago.93

A map of the hummingbird family tree – reconstructed from analysis of 284 species – shows rapid diversification from 22 million years ago.94 Hummingbirds fall into nine main clades – the topazes, hermits, mangoes, brilliants, coquettes, the giant hummingbird, mountaingems, bees, and emeralds – defining their relationship to nectar-bearing flowering plants which attract hummingbirds into new geographic areas.959697

Molecular phylogenetic studies of the hummingbirds have shown that the family is composed of nine major clades.9899 When Edward Dickinson and James Van Remsen Jr. updated the Howard and Moore Complete Checklist of the Birds of the World for the 4th edition in 2013, they divided the hummingbirds into six subfamilies.100

Molecular phylogenetic studies determined the relationships between the major groups of hummingbirds.101102 In the cladogram below, the English names are those introduced in 1997.103 The scientific names are those introduced in 2013.104

Trochilidae

Florisuginae – topazes

Phaethornithinae – hermits

Polytminae – mangoes

Lesbiinae

Heliantheini – brilliants

Lesbiini – coquettes

Patagoninae – giants

Trochilinae

Lampornithini – mountain gems

Mellisugini – bees

Trochilini – emeralds

While all hummingbirds depend on flower nectar to fuel their high metabolisms and hovering flight, coordinated changes in flower and bill shape stimulated the formation of new species of hummingbirds and plants. Due to this exceptional evolutionary pattern, as many as 140 hummingbird species can coexist in a specific region, such as the Andes range.105

The hummingbird evolutionary tree shows that one key evolutionary factor appears to have been an altered taste receptor that enabled hummingbirds to seek nectar.106

Upon maturity, males of a particular species, Phaethornis longirostris, the long-billed hermit, appear to be evolving a dagger-like weapon on the beak tip as a secondary sexual trait to defend mating areas.107

Geographic diversification

The Andes Mountains appear to be a particularly rich environment for hummingbird evolution because diversification occurred simultaneously with mountain uplift over the past 10 million years.108 Hummingbirds remain in dynamic diversification inhabiting ecological regions across South America, North America, and the Caribbean, indicating an enlarging evolutionary radiation.109

Within the same geographic region, hummingbird clades coevolved with nectar-bearing plant clades, affecting mechanisms of pollination.110111 The same is true for the sword-billed hummingbird (Ensifera ensifera), one of the morphologically most extreme species, and one of its main food plant clades (Passiflora section Tacsonia).112

Coevolution with ornithophilous flowers

Hummingbirds are specialized nectarivores tied to the ornithophilous flowers upon which they feed.113 This coevolution implies that morphological traits of hummingbirds, such as bill length, bill curvature, and body mass, are correlated with morphological traits of plants, such as corolla length, curvature, and volume.114 Some species, especially those with unusual bill shapes, such as the sword-billed hummingbird and the sicklebills, are coevolved with a small number of flower species. Even in the most specialized hummingbird–plant mutualisms, the number of food plant lineages of the individual hummingbird species increases with time.115 The bee hummingbird (Mellisuga helenae) – the world's smallest bird – evolved to dwarfism likely because it had to compete with long-billed hummingbirds having an advantage for nectar foraging from specialized flowers, consequently leading the bee hummingbird to more successfully compete for flower foraging against insects.116117

Many plants pollinated by hummingbirds produce flowers in shades of red, orange, and bright pink, although the birds take nectar from flowers of other colors. Hummingbirds can see wavelengths into the near-ultraviolet, but hummingbird-pollinated flowers do not reflect these wavelengths as many insect-pollinated flowers do. This narrow color spectrum may render hummingbird-pollinated flowers relatively inconspicuous to most insects, thereby reducing nectar robbing.118119 Hummingbird-pollinated flowers also produce relatively weak nectar (averaging 25% sugars) containing a high proportion of sucrose, whereas insect-pollinated flowers typically produce more concentrated nectars dominated by fructose and glucose.120

Hummingbirds and the plants they visit for nectar have a tight coevolutionary association, generally called a plant–bird mutualistic network.121 These birds show high specialization and modularity, especially in communities with high species richness. These associations are also observed when closely related hummingbirds, such as two species of the same genus, visit distinct sets of flowering species.122123

Sexual dimorphisms

Hummingbirds exhibit sexual size dimorphism according to Rensch's rule,124 in which males are smaller than females in small-bodied species, and males are larger than females in large-bodied species.125 The extent of this sexual size difference varies among clades of hummingbirds.126127 For example, the Mellisugini clade (bees) exhibits a large size dimorphism, with females being larger than males.128 Conversely, the Lesbiini clade (coquettes) displays very little size dimorphism; males and females are similar in size.129 Sexual dimorphisms in bill size and shape are also present between male and female hummingbirds,130 where in many clades, females have longer, more curved bills favored for accessing nectar from tall flowers.131 For males and females of the same size, females tend to have larger bills.132

Sexual size and bill differences likely evolved due to constraints imposed by courtship, because mating displays of male hummingbirds require complex aerial maneuvers.133 Males tend to be smaller than females, allowing conservation of energy to forage competitively and participate more frequently in courtship.134 Thus, sexual selection favors smaller male hummingbirds.135

Female hummingbirds tend to be larger, requiring more energy, with longer beaks that allow for more effective reach into crevices of tall flowers for nectar.136 Thus, females are better at foraging, acquiring flower nectar, and supporting the energy demands of their larger body size.137 Directional selection thus favors the larger hummingbirds in terms of acquiring food.138

Another evolutionary cause of this sexual bill dimorphism is that the selective forces from competition for nectar between the sexes of each species drives sexual dimorphism.139 Depending on which sex holds territory in the species, the other sex having a longer bill and being able to feed on a wide variety of flowers is advantageous, decreasing intraspecific competition.140 For example, in species of hummingbirds where males have longer bills, males do not hold a specific territory and have a lek mating system.141 In species where males have shorter bills than females, males defend their resources, so females benefit from a longer bill to feed from a broader range of flowers.142

Feather colors

The hummingbird plumage coloration gamut, particularly for blue, green, and purple colors in the gorget and crown of males, occupies 34% of the total color space for bird feathers.143 White (unpigmented) feathers have the lowest incidence in the hummingbird color gamut.144 Hummingbird plumage color diversity evolved from sexual and social selection on plumage coloration, which correlates with the rate of hummingbird species development over millions of years.145 Bright plumage colors in males are part of aggressive competition for flower resources and mating.146147 The bright colors result from pigmentation in the feathers and from prismal cells within the top layers of feathers of the head, gorget, breast, back and wings.148149 When sunlight hits these cells, it is split into wavelengths that reflect to the observer in varying degrees of intensity,150 with the feather structure acting as a diffraction grating.151 Iridescent hummingbird colors result from a combination of refraction and pigmentation, since the diffraction structures themselves are made of melanin, a pigment,152153 and may also be colored by carotenoid pigmentation and more subdued black, brown or gray colors dependent on melanin.154

By merely shifting position, feather regions of a muted-looking bird can instantly become fiery red or vivid green.155 In courtship displays for one example, males of the colorful Anna's hummingbird orient their bodies and feathers toward the sun to enhance the display value of iridescent plumage toward a female of interest.156

One study of Anna's hummingbirds found that dietary protein was an influential factor in feather color, as birds receiving more protein grew significantly more colorful crown feathers than those fed a low-protein diet.157 Additionally, birds on a high-protein diet grew yellower (higher hue) green tail feathers than birds on a low-protein diet.158

Specialized characteristics and metabolism

Humming

Hummingbirds are named for the prominent humming sound their wingbeats make while flying and hovering to feed or interact with other hummingbirds.159 Humming serves communication purposes by alerting other birds of the arrival of a fellow forager or potential mate.160 The humming sound derives from aerodynamic forces generated by the downstrokes and upstrokes of the rapid wingbeats, causing oscillations and harmonics that evoke an acoustic quality likened to that of a musical instrument.161162 The humming sound of hummingbirds is unique among flying animals, compared to the whine of mosquitoes, buzz of bees, and "whoosh" of larger birds.163164

The wingbeats causing the hum of hummingbirds during hovering are achieved by elastic recoil of wing strokes produced by the main flight muscles: the pectoralis major (the main downstroke muscle) and supracoracoideus (the main upstroke muscle).165

Vision

Although hummingbird eyes are small in diameter (5–6 mm), they are accommodated in the skull by reduced skull ossification, and occupy a larger proportion of the skull compared to other birds and animals.166

Further, hummingbird eyes have large corneas, which comprise about 50% of the total transverse eye diameter, combined with an extraordinary density of retinal ganglion cells responsible for visual processing, containing some 45,000 neurons per mm2.167 The enlarged cornea relative to total eye diameter serves to increase the amount of light perception by the eye when the pupil is dilated maximally, enabling nocturnal flight.168

During evolution, hummingbirds adapted to the navigational needs of visual processing while in rapid flight or hovering by development of the exceptionally dense array of retinal neurons, allowing for increased spatial resolution in the lateral and frontal visual fields.169 Morphological studies of the hummingbird brain showed that neuronal hypertrophy – relatively the largest in any bird – exists in a region called the pretectal nucleus lentiformis mesencephali (called the nucleus of the optic tract in mammals) responsible for refining dynamic visual processing while hovering and during rapid flight.170171

The enlargement of the brain region responsible for visual processing indicates an enhanced ability for perception and processing of fast-moving visual stimuli encountered during rapid forward flight, insect foraging, competitive interactions, and high-speed courtship.172173 A study of broad-tailed hummingbirds indicated that hummingbirds have a fourth color-sensitive visual cone (humans have three) that detects ultraviolet light and enables discrimination of non-spectral colors, possibly having a role in flower identity, courtship displays, territorial defense, and predator evasion.174 The fourth color cone would extend the range of visible colors for hummingbirds to perceive ultraviolet light and color combinations of feathers and gorgets, colorful plants, and other objects in their environment, enabling detection of as many as five non-spectral colors, including purple, ultraviolet-red, ultraviolet-green, ultraviolet-yellow, and ultraviolet-purple.175

Hummingbirds are highly sensitive to stimuli in their visual fields, responding to even minimal motion in any direction by reorienting themselves in midflight.176177178 Their visual sensitivity allows them to precisely hover in place while in complex and dynamic natural environments,179 functions enabled by the lentiform nucleus which is tuned to fast-pattern velocities, enabling highly tuned control and collision avoidance during forward flight.180

Song, vocal learning, and hearing

Many hummingbird species exhibit a diverse vocal repertoire of chirps, squeaks, whistles and buzzes.181182 Vocalizations vary in complexity and spectral content during social interactions, foraging, territorial defense, courtship, and mother-nestling communication.183 Territorial vocal signals may be produced in rapid succession to discourage aggressive encounters, with the chirping rate and loudness increasing when intruders persist.184 During the breeding season, male and female hummingbirds vocalize as part of courtship.185

Hummingbirds exhibit vocal production learning to enable song variation – "dialects" that exist across the same species.186 For example, the blue-throated hummingbird's song differs from typical oscine songs in its wide frequency range, extending from 1.8 kHz to about 30 kHz.187 It also produces ultrasonic vocalizations which do not function in communication.188 As blue-throated hummingbirds often alternate singing with catching small flying insects, it is possible the ultrasonic clicks produced during singing disrupt insect flight patterns, making insects more vulnerable to predation.189 Anna's, Costa's, long-billed hermits, and Andean hummingbirds have song dialects that vary across habitat locations and phylogenetic clades.190191

The avian vocal organ, the syrinx, plays an important role in understanding hummingbird song production.192 What makes the hummingbird's syrinx different from that of other birds in the Apodiformes order is the presence of internal muscle structure, accessory cartilages, and a large tympanum that serves as an attachment point for external muscles, all of which are adaptations thought to be responsible for the hummingbird's increased ability in pitch control and large frequency range.193194

Hummingbird songs originate from at least seven specialized nuclei in the forebrain.195196 A genetic expression study showed that these nuclei enable vocal learning (ability to acquire vocalizations through imitation), a rare trait known to occur in only two other groups of birds (parrots and songbirds) and a few groups of mammals (including humans, whales and dolphins, and bats).197 Within the past 66 million years, only hummingbirds, parrots, and songbirds out of 23 bird orders may have independently evolved seven similar forebrain structures for singing and vocal learning, indicating that evolution of these structures is under strong epigenetic constraints possibly derived from a common ancestor.198199

Generally, birds have been assessed to vocalize and hear in the range of 2–5 kHz, with hearing sensitivity falling with higher frequencies.200 In the Ecuadorian hillstar (Oreotrochilus chimborazo), vocalizations were recorded in the wild to be at a frequency above 10 kHz, well outside of the known hearing ability of most birds.201 Song system nuclei in the hummingbird brain are similar to those songbird brains, but the hummingbird brain has specialized regions involved for song processing.202

Metabolism

Hummingbirds have the highest metabolism of all vertebrate animals – a necessity to support the rapid beating of their wings during hovering and fast forward flight.203204 During flight and hovering, oxygen consumption per gram of muscle tissue in a hummingbird is about 10 times higher than that measured in elite human athletes.205 Hummingbirds achieve this extraordinary capacity for oxygen consumption by an exceptional density and proximity of capillaries and mitochondria in their flight muscles.206

Hummingbirds are rare among vertebrates in their ability to rapidly make use of ingested sugars to fuel energetically expensive hovering flight, powering up to 100% of their metabolic needs with the sugars they drink.207 Hummingbird flight muscles have extremely high capacities for oxidizing carbohydrates and fatty acids via hexokinase, carnitine palmitoyltransferase, and citrate synthase enzymes at rates that are the highest known for vertebrate skeletal muscle.208 To sustain rapid wingbeats during flight and hovering, hummingbirds expend the human equivalent of 150,000 calories per day,209 an amount estimated to be 10 times the energy consumption by a marathon runner in competition.210

Hummingbirds can use newly ingested sugars to fuel hovering flight within 30–45 minutes of consumption.211212 These data suggest that hummingbirds are able to oxidize sugar in flight muscles at rates rapid enough to satisfy their extreme metabolic demands – as indicated by a 2017 review showing that hummingbirds have in their flight muscles a mechanism for "direct oxidation" of sugars into maximal ATP yield to support a high metabolic rate for hovering, foraging at altitude, and migrating.213 This adaptation occurred through the evolutionary loss of a key gene, fructose-bisphosphatase 2 (FBP2), coinciding with the onset of hovering by hummingbirds estimated by fossil evidence to be some 35 million years ago.214215 Without FBP2, glycolysis and mitochondrial respiration in flight muscles are enhanced, enabling hummingbirds to metabolize sugar more efficiently for energy.216217

By relying on newly ingested sugars to fuel flight, hummingbirds reserve their limited fat stores to sustain their overnight fasting during torpor or to power migratory flights.218 Studies of hummingbird metabolism address how a migrating ruby-throated hummingbird can cross 800 km (500 mi) of the Gulf of Mexico on a nonstop flight.219 This hummingbird, like other long-distance migrating birds, stores fat as a fuel reserve, augmenting its weight by as much as 100%, then enabling metabolic fuel for flying over open water.220221 The amount of fat (1–2 g) used by a migrating hummingbird to cross the Gulf of Mexico in a single flight is similar to that used by a human climbing about 50 feet (15 m).222

The heart rate of hummingbirds can reach as high as 1,260 beats per minute, a rate measured in a blue-throated hummingbird with a breathing rate of 250 breaths per minute at rest.223224

Heat dissipation

The high metabolic rate of hummingbirds – especially during rapid forward flight and hovering – produces increased body heat that requires specialized mechanisms of thermoregulation for heat dissipation, which becomes an even greater challenge in hot, humid climates.225 Hummingbirds dissipate heat partially by evaporation through exhaled air, and from body structures with thin or no feather covering, such as around the eyes, shoulders, under the wings (patagia), and feet.226227

While hovering, hummingbirds do not benefit from the heat loss by air convection during forward flight, except for air movement generated by their rapid wing-beat, possibly aiding convective heat loss from the extended feet.228229 Smaller hummingbird species, such as the calliope, appear to adapt their relatively higher surface-to-volume ratio to improve convective cooling from air movement by the wings.230 When air temperatures rise above 36 °C (97 °F), thermal gradients driving heat passively by convective dissipation from around the eyes, shoulders, and feet are reduced or eliminated, requiring heat dissipation mainly by evaporation and exhalation.231 In cold climates, hummingbirds retract their feet into breast feathers to eliminate skin exposure and minimize heat dissipation.232

Kidney function

The dynamic range of metabolic rates in hummingbirds233 requires a parallel dynamic range in kidney function.234 During a day of nectar consumption with a corresponding high water intake that may total five times the body weight per day, hummingbird kidneys process water via glomerular filtration rates (GFR) in amounts proportional to water consumption, thereby avoiding overhydration.235236 During brief periods of water deprivation, however, such as in nighttime torpor, GFR drops to zero, preserving body water.237238

Hummingbird kidneys also have a unique ability to control the levels of electrolytes after consuming nectars with high amounts of sodium and chloride or none, indicating that kidney and glomerular structures must be highly specialized for variations in nectar mineral quality.239 Morphological studies on Anna's hummingbird kidneys showed adaptations of high capillary density in close proximity to nephrons, allowing for precise regulation of water and electrolytes.240241

Hemoglobin adaptation to altitude

Dozens of hummingbird species live year-round in tropical mountain habitats at high altitudes, such as in the Andes over ranges of 1,500 metres (4,900 ft) to 5,200 metres (17,100 ft) where the partial pressure of oxygen in the air is reduced, a condition of hypoxic challenge for the high metabolic demands of hummingbirds.242243244 In Andean hummingbirds living at high elevations, researchers found that the oxygen-carrying protein in blood – hemoglobin – had increased oxygen-binding affinity, and that this adaptive effect likely resulted from evolutionary mutations within the hemoglobin molecule via specific amino acid changes due to natural selection.245246247

Adaptation to winter

Anna's hummingbirds are the northernmost year-round residents of any hummingbird. Anna's hummingbirds were recorded in Alaska as early as 1971, and resident in the Pacific Northwest since the 1960s, particularly increasing as a year-round population during the early 21st century.248249 Scientists estimate that some Anna's hummingbirds overwinter and presumably breed at northern latitudes where food and shelter are available throughout winter, tolerating moderately cold winter temperatures.250251

During cold temperatures, Anna's hummingbirds gradually gain weight during the day as they convert sugar to fat.252253 In addition, hummingbirds with inadequate stores of body fat or insufficient plumage are able to survive periods of subfreezing weather by lowering their metabolic rate and entering a state of torpor.254

While their range was originally limited to the chaparral of California and Baja California, it expanded northward to Oregon, Washington, and British Columbia, and east to Arizona over the 1960s to 1970s.255 This rapid expansion is attributed to the widespread planting of non-native species, such as eucalyptus, as well as the use of urban bird feeders, in combination with the species' natural tendency for extensive postbreeding dispersal.256 In the Pacific Northwest, the fastest growing populations occur in regions with breeding-season cold temperatures similar to those of its native range.257 Northward expansion of the Anna's hummingbird represents an ecological release associated with introduced plants, year-round nectar availability from feeders supplied by humans, milder winter temperatures associated with climate change, and acclimation of the species to a winter climate cooler than its native region.258259 Although quantitative data are absent, it is likely that a sizable percentage of Anna's hummingbirds in the Pacific Northwest still do migrate south for winter, as of 2017.260

Anna's hummingbird is the official city bird of Vancouver, British Columbia, Canada,261 and is a non-migrating resident of Seattle where it lives year-round through winter enduring extended periods of subfreezing temperatures, snow, and high winds.262

Torpor

The metabolism of hummingbirds can slow at night or at any time when food is not readily available; the birds enter a deep-sleep state (known as torpor) to prevent energy reserves from falling to a critical level. One study of broad-tailed hummingbirds found that body weight decreased linearly throughout torpor at a rate of 0.04 g per hour.263

During nighttime torpor, body temperature in a Caribbean hummingbird was shown to fall from 40 to 18 °C,264 with heart and breathing rates slowing dramatically (heart rate of roughly 50 to 180 bpm from its daytime rate of higher than 1000 bpm).265 Recordings from a Metallura phoebe hummingbird in noctural torpor at around 3,800 metres (12,500 ft) in the Andes mountains showed that body temperature fell to 3.3 °C (38 °F), the lowest known level for a bird or non-hibernating mammal.266267 During cold nights at altitude, hummingbirds were in torpor for 2–13 hours depending on species, with cooling occurring at the rate of 0.6 °C per minute and rewarming at 1–1.5 °C per minute.268 High-altitude Andean hummingbirds also lost body weight in negative proportion to how long the birds were in torpor, losing about 6% of weight each night.269

During torpor, to prevent dehydration, the kidney function declines, preserving needed compounds, such as glucose, water, and nutrients.270 The circulating hormone, corticosterone, is one signal that arouses a hummingbird from torpor.271

Use and duration of torpor vary among hummingbird species and are affected by whether a dominant bird defends territory, with nonterritorial subordinate birds having longer periods of torpor.272 A hummingbird with a higher fat percentage will be less likely to enter a state of torpor compared to one with less fat, as a bird can use the energy from its fat stores.273 Torpor in hummingbirds appears to be unrelated to nighttime temperature, as it occurs across a wide temperature range, with energy savings of such deep sleep being more related to the photoperiod and duration of torpor.274

Lifespan

Hummingbirds have unusually long lifespans for organisms with such rapid metabolisms. Though many die during their first year of life, especially in the vulnerable period between hatching and fledging, those that survive may occasionally live a decade or more.275 Among the better-known North American species, the typical lifespan is probably 3 to 5 years.276 For comparison, the smaller shrews, among the smallest of all mammals, seldom live longer than 2 years.277 The longest recorded lifespan in the wild relates to a female broad-tailed hummingbird that was banded as an adult at least one year old, then recaptured 11 years later, making her at least 12 years old.278 Other longevity records for banded hummingbirds include an estimated minimum age of 10 years 1 month for a female black-chinned hummingbird similar in size to the broad-tailed hummingbird, and at least 11 years 2 months for a much larger buff-bellied hummingbird.279

Natural enemies

Predators

Praying mantises have been observed as predators of hummingbirds.280281282 Other predators include domestic cats, dragonflies, frogs, orb-weaver spiders, and other birds, such as the roadrunner.283284

Parasites

Hummingbirds host a highly specialized lice fauna. Two genera of Ricinid lice, Trochiloecetes and Trochiliphagus, are specialized on them, often infesting 5–15% of their populations. In contrast, two genera of Menoponid lice, Myrsidea and Leremenopon, are extremely rare on them.285286

Reproduction

Male hummingbirds do not take part in nesting.287 Most species build a cup-shaped nest on the branch of a tree or shrub.288 The nest varies in size relative to the particular species – from smaller than half a walnut shell to several centimeters in diameter.289

Many hummingbird species use spider silk and lichen to bind the nest material together and secure the structure.290291 The unique properties of the silk allow the nest to expand as the young hummingbirds grow. Two white eggs are laid,292293 which despite being the smallest of all bird eggs, are large relative to the adult hummingbird's size.294 Incubation lasts 14 to 23 days, depending on the species, ambient temperature, and female attentiveness to the nest.295296 The mother feeds her nestlings on small arthropods and nectar by inserting her bill into the open mouth of a nestling, and then regurgitating the food into its crop.297 Hummingbirds stay in the nest for 18–22 days, after which they leave the nest to forage on their own, although the mother bird may continue feeding them for another 25 days.298

Flight

Hummingbird flight has been studied intensively from an aerodynamic perspective using wind tunnels and high-speed video cameras. Two studies of rufous or Anna's hummingbirds in a wind tunnel used particle image velocimetry techniques to investigate the lift generated on the bird's upstroke and downstroke.299300 The birds produced 75% of their weight support during the downstroke and 25% during the upstroke, with the wings making a "figure 8" motion.301

Many earlier studies had assumed that lift was generated equally during the two phases of the wingbeat cycle, as is the case of insects of a similar size.302 This finding shows that hummingbird hovering is similar to, but distinct from, that of hovering insects such as the hawk moth.303 Further studies using electromyography in hovering rufous hummingbirds showed that muscle strain in the pectoralis major (principal downstroke muscle) was the lowest yet recorded in a flying bird, and the primary upstroke muscle (supracoracoideus) is proportionately larger than in other bird species.304 Presumably due to rapid wingbeats for flight and hovering, hummingbird wings have adapted to perform without an alula.305

The giant hummingbird's wings beat as few as 12 times per second,306 and the wings of typical hummingbirds beat up to 80 times per second.307 As air density decreases, for example, at higher altitudes, the amount of power a hummingbird must use to hover increases. Hummingbird species adapted for life at higher altitudes, therefore, have larger wings to help offset these negative effects of low air density on lift generation.308

A slow-motion video has shown how the hummingbirds deal with rain when they are flying. To remove the water from their heads, they shake their heads and bodies, similar to a dog shaking, to shed water.309 Further, when raindrops collectively may weigh as much as 38% of the bird's body weight, hummingbirds shift their bodies and tails horizontally, beat their wings faster, and reduce their wings' angle of motion when flying in heavy rain.310

Wingbeats and flight stability

The highest recorded wingbeat rate for hummingbirds during hovering is 99.1 per second, as measured for male woodstars (Chaetocercus sp.).311 Males in the genus Chaetocercus have been recorded above 100 beats per second during courtship displays.312 The number of beats per second increases above "normal" hovering while flying during courtship displays (up to 90 per second for the calliope hummingbird, Selasphorus calliope); a wingbeat rate 40% higher than its typical hovering rate.313

During turbulent airflow conditions created experimentally in a wind tunnel, hummingbirds exhibit stable head positions and orientation when they hover at a feeder.314 When wind gusts from the side, hummingbirds compensate by increasing wing-stroke amplitude and stroke plane angle and by varying these parameters asymmetrically between the wings and from one stroke to the next.315 They also vary the orientation and enlarge the collective surface area of their tail feathers into the shape of a fan.316 While hovering, the visual system of a hummingbird is able to separate apparent motion caused by the movement of the hummingbird itself from motions caused by external sources, such as an approaching predator.317 In natural settings full of highly complex background motion, hummingbirds are able to precisely hover in place by rapid coordination of vision with body position.318

Feather sounds

Courtship dives

When courting, the male Anna's hummingbird ascends some 35 m (115 ft) above a female, before diving at a speed of 27 m/s (89 ft/s), equal to 385 body lengths/sec – producing a high-pitched sound near the female at the nadir of the dive.319 This downward acceleration during a dive is the highest reported for any vertebrate undergoing a voluntary aerial maneuver; in addition to acceleration, the speed relative to body length is the highest known for any vertebrate. For instance, it is about twice the diving speed of peregrine falcons in pursuit of prey.320 At maximum descent speed, about 10 g of gravitational force occur in the courting hummingbird during a dive (Note: G-force is generated as the bird pulls out of the dive).321322

The outer tail feathers of male Anna's (Calypte anna) and Selasphorus hummingbirds (e.g., Allen's, calliope) vibrate during courtship display dives and produce an audible chirp caused by aeroelastic flutter.323324 Hummingbirds cannot make the courtship dive sound when missing their outer tail feathers, and those same feathers could produce the dive sound in a wind tunnel.325 The bird can sing at the same frequency as the tail-feather chirp, but its small syrinx is not capable of the same volume.326 The sound is caused by the aerodynamics of rapid air flow past tail feathers, causing them to flutter in a vibration, which produces the high-pitched sound of a courtship dive.327328

Many other species of hummingbirds also produce sounds with their wings or tails while flying, hovering, or diving, including the wings of the calliope hummingbird,329 broad-tailed hummingbird, rufous hummingbird, Allen's hummingbird, and the streamertail species, as well as the tail of the Costa's hummingbird and the black-chinned hummingbird, and a number of related species.330 The harmonics of sounds during courtship dives vary across species of hummingbirds.331

Wing feather trill

Male rufous and broad-tailed hummingbirds (genus Selasphorus) have a distinctive wing feature during normal flight that sounds like jingling or a buzzing shrill whistle – a trill.332 The trill arises from air rushing through slots created by the tapered tips of the ninth and tenth primary wing feathers, creating a sound loud enough to be detected by female or competitive male hummingbirds and researchers up to 100 m away.333

Behaviorally, the trill serves several purposes: It announces the sex and presence of a male bird; it provides audible aggressive defense of a feeding territory and an intrusion tactic; it enhances communication of a threat; and it favors mate attraction and courtship.334

Migration

Relatively few hummingbirds migrate as a percentage of the total number of species; of the roughly 366 known hummingbird species, only 12–15 species migrate annually, particularly those in North America.335 Most hummingbirds live in the Amazonia-Central America tropical rainforest belt, where seasonal temperature changes and food sources are relatively constant, obviating the need to migrate.336 As the smallest living birds, hummingbirds are relatively limited at conserving heat energy, and are generally unable to maintain a presence in higher latitudes during winter months, unless the specific location has a large food supply throughout the year, particularly access to flower nectar.337 Other migration factors are seasonal fluctuation of food, climate, competition for resources, predators, and inherent signals.338

Most North American hummingbirds migrate southward in fall to spend winter in Mexico, the Caribbean Islands, or Central America.339 A few species are year-round residents of Florida, California, and the southwestern desert regions of the US.340 Among these are Anna's hummingbird, a common resident from southern Arizona and inland California, and the buff-bellied hummingbird, a winter resident from Florida across the Gulf Coast to South Texas.341 Ruby-throated hummingbirds are common along the Atlantic flyway, and migrate in summer from as far north as Atlantic Canada, returning to Mexico, South America, southern Texas, and Florida to winter.342343 During winter in southern Louisiana, black-chinned, buff-bellied, calliope, Allen's, Anna's, ruby-throated, rufous, broad-tailed, and broad-billed hummingbirds are present.344

The rufous hummingbird breeds farther north than any other species of hummingbird, spending summers along coastal British Columbia and Alaska, and wintering in the southwestern United States and Mexico,345 with some distributed along the coasts of the subtropical Gulf of Mexico and Florida.346 By migrating in spring as far north as the Yukon or southern Alaska,347 the rufous hummingbird migrates more extensively and nests farther north than any other hummingbird species, and must tolerate occasional temperatures below freezing in its breeding territory. This cold hardiness enables it to survive temperatures below freezing, provided that adequate shelter and food are available.348

As calculated by displacement of body size, the rufous hummingbird makes perhaps the longest migratory journey of any bird in the world. At just over 3 inches (7.6 cm) long, rufous hummingbirds travel 3,900 miles (6,300 km) one-way from Alaska to Mexico in late summer, a distance equal to 78,470,000 body lengths, then make the return journey in the following spring.349350 By comparison, the 13 inches (33 cm)-long Arctic tern makes a one-way flight of about 18,000 kilometres (11,000 mi), or 51,430,000 body lengths, just 65% of the body displacement during migration by rufous hummingbirds.351

The northward migration of rufous hummingbirds occurs along the Pacific flyway,352 and may be time-coordinated with flower and tree-leaf emergence in early spring, and also with availability of insects as food.353 Arrival at breeding grounds before nectar availability from mature flowers may jeopardize breeding opportunities.354

Feeding

All hummingbirds are overwhelmingly nectarivorous,355356357358359360 being by far the most specialized such feeders among birds, as well as the only birds for whom nectar typically comprises the vast majority of energy intake. Hummingbirds exhibit numerous and extensive adaptations to nectarivory, including long, probing bills and tongues which rapidly take up fluids. Hummingbirds also possess the most sophisticated hovering flight of all birds, a necessity for rapidly visiting many flowers without perching. Their intestines are capable of extracting over 99% of the glucose from nectar feedings within minutes, owing to high densities of glucose transporters (the highest known among vertebrates).361

As among the most important vertebrate pollinators, hummingbirds have coevolved in complex ways with flowering plants; thousands of New World species have evolved to be pollinated exclusively by hummingbirds, even barring access to insect pollinators.362363 In some plants these mechanisms, which include highly modified corollas, even render their nectaries inaccessible to all but certain hummingbirds, i.e., those possessing appropriate beak morphologies (although some hummingbirds rob nectar to overcome this). Bird-pollinated plants (also termed "ornithophilous") were formerly thought to exemplify very close mutualisms, with specific flowering plants coevolving alongside specific hummingbirds in mutualistic pairings. Both ornithophilous plants and hummingbirds are now known to not be nearly selective enough for this to be true.364365366 Less accessible ornithophiles (for example, those requiring long bills) still rely on multiple hummingbird species for pollination. More importantly, hummingbirds tend not to be especially selective nectar-feeders, even regularly visiting non-ornithophilous plants, as well as ornithophiles which appear poorly suited for feeding by their species. Feeding efficiency is optimized, however, when birds feed on flowers better suited to their bill morphologies.367368

Although they may not be one-to-one, there are still marked overall preferences for certain genera, families, and orders of flowering plants by hummingbirds in general, as well as by certain species of hummingbird. Flowers which are attractive to hummingbirds are often colorful (particularly red), open diurnally, and produce nectar with a high sucrose content; in ornithophilous plants, the corollas are often elongated and tubular, and they may be scentless (several of these are adaptations discouraging insect visitation).369 Some common genera consumed by many species include Castilleja, Centropogon, Costus, Delphinium, Heliconia, Hibiscus, Inga, and Mimulus; some of these are primarily insect-pollinated. Three Californian species were found to feed from 62 plant families in 30 orders, with the most frequently occurring orders being Apiales, Fabales, Lamiales, and Rosales. A hummingbird may have to visit one or two thousand flowers daily to meet energy demands.370371372

Although a high-quality source of energy, nectar is deficient in many macro- and micronutrients;373374375 it tends to be low in lipids, and although it may contain trace quantities of amino acids, some essential acids are severely or entirely lacking. Though hummingbird protein requirements appear to be quite small, at 1.5% of the diet, nectar is still an inadequate source;376 most if not all hummingbirds therefore supplement their diet with the consumption of invertebrates.377378379380 Insectivory is not thought to be calorically important; nonetheless, regular consumption of arthropods is considered crucial for birds to thrive. In fact, it has been suggested that the majority of non-caloric nutritional needs of hummingbirds are met by insectivory, but nectars do contain appreciable quantities of certain vitamins and minerals.381 (Here, "insectivory" refers to the consumption of any arthropod, not exclusively insects).

Though not as insectivorous as once believed, and far less so than most of their relatives and ancestors among the Strisores (e.g., swifts), insectivory is probably of regular importance to most hummingbirds. About 95% of individuals from 140 species in one study showed evidence of arthropod consumption,382 while another study found arthropod remains in 79% of over 1600 birds from sites across South and Central America.383 Some species have even been recorded to be largely or entirely insectivorous for periods of time, particularly when nectar sources are scarce, and possibly, for some species, with seasonal regularity in areas with a wet season. Observations of seasonal, near-exclusive insectivory have been made for blue-throated hummingbirds,384 as well as swallow-tailed hummingbirds in an urban park in Brazil.385 In Arizona, when nearby nectar sources were seemingly absent, a nesting female broad-tailed hummingbird was recorded feeding only on arthropods for two weeks.386 Other studies report 70–100% of feeding time devoted to arthropods;387388 these accounts suggest a degree of adaptability, particularly when appropriate nectar sources are unavailable, although nectarivory always predominates when flowers are abundant (e.g., in non-seasonal tropical habitats). In addition, the aforementioned Arizona study only surveyed a small portion of the study area, and mostly did not observe the bird while she was off the nest. Similar concerns have been raised for other reports, leading to skepticism over whether hummingbirds can in fact subsist without nectar for extended periods at all.389

Hummingbirds exhibit various feeding strategies and some morphological adaptations for insectivory.390 Typically, they hawk for small flying insects, but also glean spiders from their webs.391392 Bill shape may play a role, as hummingbirds with longer or more curved bills may be unable to hawk efficiently, and so rely more heavily on gleaning spiders.393 Regardless of bill shape, spiders are a common prey item; other very common prey items include flies, especially those of the family Chironomidae, as well as various Hymenopterans (such as wasps and ants) and Hemipterans.394395396 The aforementioned California study found three species to consume invertebrates from 72 families in 15 orders, with flies alone occurring in over 90% of samples; the three species exhibited high dietary overlap, with little evidence for niche partitioning.397 This suggests that prey availability is not a limiting resource for hummingbirds.

Estimates of overall dietary makeup for hummingbirds vary, but insectivory is often cited as comprising 5–15% of feeding time budgets, typically;398399400 2–12% is a figure that is also cited.401402 In one study, 84% of feeding time was allotted to nectar feeding if breeding females are included, and 89% otherwise; 86% of total feeding records were on nectar.403404 It has been estimated, based on time budgets and other data, that the hummingbird diet is generally about 90% nectar and 10% arthropods by mass.405406 As their nestlings consume only arthropods, and possibly because their own requirements increase, breeding females spend 3–4 times as long as males foraging for arthropods, although 65–70% of their feeding time is still devoted to nectar.407 Estimates for overall insectivory can be as low as <5%. Such low numbers have been documented for some species; insects comprised 3% of foraging attempts for Peruvian shining sunbeams in one study,408 while the purple-throated carib has been reported to spend <1% of time consuming insects in Dominica.409 Both species also have more typical numbers recorded elsewhere, however. Overall, for most hummingbirds, insectivory is an essential and regular, albeit minor, component of the diet, while nectar is the primary feeding focus when conditions allow.410411 It has been shown that floral abundance (but not floral diversity) influences hummingbird diversity, but that arthropod abundance does not (i.e., that it is non-limiting).412413

Hummingbirds do not spend all day flying, as the energy cost would be prohibitive; the majority of their activity consists simply of sitting or perching. Hummingbirds eat many small meals and consume around half their weight in nectar (twice their weight in nectar, if the nectar is 25% sugar) each day.414 Hummingbirds digest their food rapidly due to their small size and high metabolism; a mean retention time less than an hour has been reported.415 Hummingbirds spend an average of 20% of their time feeding and 75–80% sitting and digesting.416

Because their high metabolism makes them vulnerable to starvation, hummingbirds are highly attuned to food sources. Some species, including many found in North America, are territorial and try to guard food sources (such as a feeder) against other hummingbirds, attempting to ensure a future food supply.417 Additionally, hummingbirds have an enlarged hippocampus, a brain region facilitating spatial memory used to map flowers previously visited during nectar foraging.418

Beak specializations

The shapes of hummingbird beaks (also called bills) vary widely as an adaptation for specialized feeding,419420 with some 7000 flowering plants pollinated by hummingbird nectar feeding.421 Hummingbird beak lengths range from about 6 millimetres (0.24 in) to as long as 110 millimetres (4.3 in).422 When catching insects in flight, a hummingbird's jaw flexes downward to widen the beak for successful capture.423

The extreme curved beaks of sicklebills are adapted for extracting nectar from the curved corolla tubes of Centropogon flowers.424 Some species, such as hermits (Phaethornis spp.), have long beaks that enable insertion deeply into flowers with long corolla tubes.425426 Thornbills have short, sharp beaks adapted for feeding from flowers with short corolla tubes and piercing the bases of longer ones. The beak of the fiery-tailed awlbill has an upturned tip adapted for feeding on nectar from tubular flowers while hovering.427

Perception of sweet nectar

Perception of sweetness in nectar evolved in hummingbirds during their genetic divergence from insectivorous swifts, their closest bird relatives.428 Although the only known sweet sensory receptor, called T1R2,429 is absent in birds, receptor expression studies showed that hummingbirds adapted a carbohydrate receptor from the T1R1-T1R3 receptor, identical to the one perceived as umami in humans, essentially repurposing it to function as a nectar sweetness receptor.430 This adaptation for taste enabled hummingbirds to detect and exploit sweet nectar as an energy source, facilitating their distribution across geographical regions where nectar-bearing flowers are available.431

Tongue as a micropump

Hummingbirds drink with their long tongues by rapidly lapping nectar. Their tongues have semicircular tubes which run down their lengths to facilitate nectar consumption via rapid pumping in and out of the nectar.432433 While capillary action was believed to be what drew nectar into these tubes,434 high-speed photography revealed that the tubes open down their sides as the tongue goes into the nectar, and then close around the nectar, trapping it so it can be pulled back into the beak over a period of 14 milliseconds per lick at a rate of up to 20 licks per second.435436 The tongue, which is forked, is compressed until it reaches nectar, then the tongue springs open, the rapid action traps the nectar which moves up the grooves, like a pump action, with capillary action not involved.437438439440 Consequently, tongue flexibility enables accessing, transporting and unloading nectar via pump action,441442 not by a capillary syphon as once believed.443

Feeders and artificial nectar

In the wild, hummingbirds visit flowers for food, extracting nectar, which is 55% sucrose, 24% glucose, and 21% fructose on a dry-matter basis.444 Hummingbirds also take sugar-water from bird feeders, which allow people to observe and enjoy hummingbirds up close while providing the birds with a reliable source of energy, especially when flower blossoms are less abundant. A negative aspect of artificial feeders, however, is that the birds may seek less flower nectar for food, and so may reduce the amount of pollination their feeding naturally provides.445

White granulated sugar is used in hummingbird feeders in a 20% concentration as a common recipe,446 although hummingbirds will defend feeders more aggressively when sugar content is at 35%, indicating preference for nectar with higher sugar content.447 Organic and "raw" sugars contain iron, which can be harmful,448 and brown sugar, agave syrup, molasses, and artificial sweeteners also should not be used.449 Honey is made by bees from the nectar of flowers, but it is not good to use in feeders because when it is diluted with water, microorganisms easily grow in it, causing it to spoil rapidly.450451452

Red food dye was once thought to be a favorable ingredient for the nectar in home feeders, but it is unnecessary.453 Commercial products sold as "instant nectar" or "hummingbird food" may also contain preservatives or artificial flavors, as well as dyes, which are unnecessary and potentially harmful.454455 Although some commercial products contain small amounts of nutritional additives, hummingbirds obtain all necessary nutrients from the insects they eat, rendering added nutrients unnecessary.456

Visual cues of foraging

Hummingbirds have exceptional visual acuity providing them with discrimination of food sources while foraging.457 Although hummingbirds are thought to be attracted to color while seeking food, such as red flowers or artificial feeders, experiments indicate that location and flower nectar quality are the most important "beacons" for foraging.458459 Hummingbirds depend little on visual cues of flower color to beacon to nectar-rich locations, but rather they use surrounding landmarks to find the nectar reward.460461462

In at least one hummingbird species – the green-backed firecrown (Sephanoides sephaniodes) – flower colors preferred are in the red-green wavelength for the bird's visual system, providing a higher contrast than for other flower colors.463 Further, the crown plumage of firecrown males is highly iridescent in the red wavelength range (peak at 650 nanometers), possibly providing a competitive advantage of dominance when foraging among other hummingbird species with less colorful plumage.464 The ability to discriminate colors of flowers and plumage is enabled by a visual system having four single cone cells and a double cone screened by photoreceptor oil droplets which enhance color discrimination.465466

Olfaction

While hummingbirds rely primarily on vision and hearing to assess competition from bird and insect foragers near food sources, they may also be able to detect by smell the presence in nectar of insect defensive chemicals (such as formic acid) and aggregation pheromones of foraging ants, which discourage feeding.467

In myth and culture

Aztecs wore hummingbird talismans, artistic representations of hummingbirds and fetishes made from actual hummingbird parts as emblematic for vigor, energy, and propensity to do work along with their sharp beaks that symbolically mimic instruments of weaponry, bloodletting, penetration, and intimacy. Hummingbird talismans were prized as drawing sexual potency, energy, vigor, and skill at arms and warfare to the wearer.468 The Aztec god of war Huitzilopochtli is often depicted in art as a hummingbird.469 Aztecs believed that fallen warriors would be reincarnated as hummingbirds.470471 The Nahuatl word huitzil translates to hummingbird.472

One of the Nazca Lines depicts a hummingbird (right).473

Trinidad and Tobago, known as "The land of the hummingbird", displays a hummingbird on its coat of arms,474 1-cent coin,475 and livery on its national airline, Caribbean Airlines.476 The Hummingbird Medal is awarded to individuals for significant contributions to Trinidad and Tobago.477

Mt. Umunhum in the Santa Cruz Mountains of Northern California is Ohlone for "resting place of the hummingbird".478

The Gibson Hummingbird is an acoustic guitar model that incorporates a pickguard in the shape of a hummingbird by Gibson Brands, a major guitar manufacturer.479

During the costume competition of the Miss Universe 2016 beauty pageant, Miss Ecuador, Connie Jiménez, wore a costume inspired by hummingbird wing feathers.480

See also

  • Birds portal

Notes

Wikiquote has quotations related to Hummingbirds.

References

  1. Gill, F.; Donsker, D.; Rasmussen, P. (29 January 2023). "IOC World Bird List (v 13.2), International Ornithological Committee". IOC World Bird List. Retrieved 5 March 2023. https://www.worldbirdnames.org/new/bow/hummingbirds ↩

  2. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  3. "Hummingbird (search)". International Union for Conservation of Nature’s Red List of Threatened Species. 2024. Retrieved 13 March 2024. https://www.iucnredlist.org/search?query=hummingbird&searchType=species ↩

  4. English, Simon G.; Bishop, Christine A.; Wilson, Scott; Smith, Adam C. (15 September 2021). "Current contrasting population trends among North American hummingbirds". Scientific Reports. 11 (1): 18369. Bibcode:2021NatSR..1118369E. doi:10.1038/s41598-021-97889-x. ISSN 2045-2322. PMC 8443710. PMID 34526619. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8443710 ↩

  5. Venable, G.X.; Gahm, K.; Prum, R.O. (June 2022). "Hummingbird plumage color diversity exceeds the known gamut of all other birds". Communications Biology. 5 (1): 576. doi:10.1038/s42003-022-03518-2. PMC 9226176. PMID 35739263. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9226176 ↩

  6. Suarez, R.K. (1992). "Hummingbird flight: Sustaining the highest mass-specific metabolic rates among vertebrates". Experientia. 48 (6): 565–570. doi:10.1007/bf01920240. PMID 1612136. S2CID 21328995. /wiki/Doi_(identifier) ↩

  7. Hargrove, J.L. (2005). "Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds". Nutrition Journal. 4: 36. doi:10.1186/1475-2891-4-36. PMC 1325055. PMID 16351726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325055 ↩

  8. Hargrove, J.L. (2005). "Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds". Nutrition Journal. 4: 36. doi:10.1186/1475-2891-4-36. PMC 1325055. PMID 16351726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325055 ↩

  9. "Hummingbirds". Migratory Bird Center, Smithsonian National Zoological Park. Archived from the original on 16 July 2012. Retrieved 1 April 2013. https://archive.today/20120716064758/http://nationalzoo.si.edu/scbi/migratorybirds/webcam/hummingbirds.cfm ↩

  10. McGuire, J.; Witt, C.; Remsen, J.V.; Corl, A.; Rabosky, D.; Altshuler, D.; Dudley, R. (2014). "Molecular phylogenetics and the diversification of hummingbirds". Current Biology. 24 (8): 910–916. Bibcode:2014CBio...24..910M. doi:10.1016/j.cub.2014.03.016. PMID 24704078. https://doi.org/10.1016%2Fj.cub.2014.03.016 ↩

  11. Mayr, Gerald (2004). "Old World fossil record of modern-type hummingbirds". Science. 304 (5672): 861–864. Bibcode:2004Sci...304..861M. doi:10.1126/science.1096856. PMID 15131303. S2CID 6845608. /wiki/Bibcode_(identifier) ↩

  12. Brusatte, SL; O'Connor, JK; Jarvis, ED (October 2015). "The origin and diversification of birds". Current Biology. 25 (19): R888–98. Bibcode:2015CBio...25.R888B. doi:10.1016/j.cub.2015.08.003. hdl:10161/11144. PMID 26439352. S2CID 3099017. https://doi.org/10.1016%2Fj.cub.2015.08.003 ↩

  13. Chiappe, Luis M. (16 April 2009). "Downsized dinosaurs: The evolutionary transition to modern birds". Evolution: Education and Outreach. 2 (2): 248–256. doi:10.1007/s12052-009-0133-4. ISSN 1936-6426. S2CID 26966516. https://doi.org/10.1007%2Fs12052-009-0133-4 ↩

  14. Hendry, Lisa (2023). "Are birds the only surviving dinosaurs?". The Trustees of The Natural History Museum, London. Retrieved 14 April 2023. https://www.nhm.ac.uk/discover/why-are-birds-the-only-surviving-dinosaurs.html ↩

  15. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  16. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  17. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  18. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  19. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  20. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  21. Glick, Adrienne (2002). "Mellisuga helenae". Animal Diversity Web. Retrieved 14 April 2023. http://animaldiversity.org/accounts/Mellisuga_helenae/ ↩

  22. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  23. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  24. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  25. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  26. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  27. Wilcox, Sean; Clark, Christopher (2022). "Sexual selection for flight performance in hummingbirds". Behavioral Ecology. 33 (6): 1093–1106. doi:10.1093/beheco/arac075. https://academic.oup.com/beheco/article/33/6/1093/6686581 ↩

  28. Hargrove, J.L. (2005). "Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds". Nutrition Journal. 4: 36. doi:10.1186/1475-2891-4-36. PMC 1325055. PMID 16351726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325055 ↩

  29. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  30. Hannemann, Emily (12 May 2022). "Hummingbird feet: Can hummingbirds walk?". Birds&Blooms. Retrieved 4 April 2023. https://www.birdsandblooms.com/birding/attracting-hummingbirds/hummingbird-feet/ ↩

  31. "Do hummingbirds have feet?". Wild Bird Scoop. 2023. Retrieved 4 April 2023. https://www.wildbirdscoop.com/do-hummingbirds-have-feet.html ↩

  32. "Do hummingbirds have feet?". Wild Bird Scoop. 2023. Retrieved 4 April 2023. https://www.wildbirdscoop.com/do-hummingbirds-have-feet.html ↩

  33. Hannemann, Emily (12 May 2022). "Hummingbird feet: Can hummingbirds walk?". Birds&Blooms. Retrieved 4 April 2023. https://www.birdsandblooms.com/birding/attracting-hummingbirds/hummingbird-feet/ ↩

  34. "Do hummingbirds have feet?". Wild Bird Scoop. 2023. Retrieved 4 April 2023. https://www.wildbirdscoop.com/do-hummingbirds-have-feet.html ↩

  35. Tobalske, Bret W.; Altshuler, Douglas L.; Powers, Donald R. (March 2004). "Take-off mechanics in hummingbirds (Trochilidae)". The Journal of Experimental Biology. 207 (Pt 8): 1345–52. Bibcode:2004JExpB.207.1345T. doi:10.1242/jeb.00889. PMID 15010485. S2CID 12323960. https://doi.org/10.1242%2Fjeb.00889 ↩

  36. "Do hummingbirds have feet?". Wild Bird Scoop. 2023. Retrieved 4 April 2023. https://www.wildbirdscoop.com/do-hummingbirds-have-feet.html ↩

  37. Glick, Adrienne (2002). "Mellisuga helenae". Animal Diversity Web. Retrieved 14 April 2023. http://animaldiversity.org/accounts/Mellisuga_helenae/ ↩

  38. Clark, C.J.; Dudley, R. (2009). "Flight costs of long, sexually selected tails in hummingbirds". Proceedings of the Royal Society B: Biological Sciences. 276 (1664): 2109–115. doi:10.1098/rspb.2009.0090. PMC 2677254. PMID 19324747. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2677254 ↩

  39. Ridgely, R.S.; Greenfield, P.G. (2001). The Birds of Ecuador, Field Guide (1 ed.). Cornell University Press. ISBN 978-0-8014-8721-7. 978-0-8014-8721-7 ↩

  40. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  41. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  42. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  43. Mohrman, Eric (22 November 2019). "How do hummingbirds mate?". Sciencing, Leaf Media Group Ltd. Retrieved 17 April 2023. https://sciencing.com/hummingbirds-mate-4566850.html ↩

  44. Mohrman, Eric (22 November 2019). "How do hummingbirds mate?". Sciencing, Leaf Media Group Ltd. Retrieved 17 April 2023. https://sciencing.com/hummingbirds-mate-4566850.html ↩

  45. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  46. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  47. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  48. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  49. "What is a hummingbird?". Smithsonian’s National Zoo and Conservation Biology Institute. 2023. Retrieved 7 March 2023. https://nationalzoo.si.edu/migratory-birds/hummingbirds ↩

  50. "Hummingbird facts and family introduction". Hummingbird Central. 2023. Retrieved 4 April 2023. https://www.hummingbirdcentral.com/hummingbird-facts.htm ↩

  51. "Hummingbird facts and family introduction". Hummingbird Central. 2023. Retrieved 4 April 2023. https://www.hummingbirdcentral.com/hummingbird-facts.htm ↩

  52. "Ruby-throated hummingbird". All About Birds, Cornell University Laboratory of Ornithology. 2023. Retrieved 23 April 2023. https://www.allaboutbirds.org/guide/Ruby-throated_Hummingbird/ ↩

  53. Glick, Adrienne (2002). "Mellisuga helenae". Animal Diversity Web. Retrieved 14 April 2023. http://animaldiversity.org/accounts/Mellisuga_helenae/ ↩

  54. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  55. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  56. "Hummingbird (search)". International Union for Conservation of Nature’s Red List of Threatened Species. 2024. Retrieved 13 March 2024. https://www.iucnredlist.org/search?query=hummingbird&searchType=species ↩

  57. "Hummingbird (search)". International Union for Conservation of Nature’s Red List of Threatened Species. 2024. Retrieved 13 March 2024. https://www.iucnredlist.org/search?query=hummingbird&searchType=species ↩

  58. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  59. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  60. English, Simon G.; Bishop, Christine A.; Wilson, Scott; Smith, Adam C. (15 September 2021). "Current contrasting population trends among North American hummingbirds". Scientific Reports. 11 (1): 18369. Bibcode:2021NatSR..1118369E. doi:10.1038/s41598-021-97889-x. ISSN 2045-2322. PMC 8443710. PMID 34526619. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8443710 ↩

  61. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  62. English, Simon G.; Bishop, Christine A.; Wilson, Scott; Smith, Adam C. (15 September 2021). "Current contrasting population trends among North American hummingbirds". Scientific Reports. 11 (1): 18369. Bibcode:2021NatSR..1118369E. doi:10.1038/s41598-021-97889-x. ISSN 2045-2322. PMC 8443710. PMID 34526619. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8443710 ↩

  63. Chillag, Amy (21 April 2023). "These tiny creatures are losing their battle to survive. Here's what we can do to save them". CNN. Retrieved 22 April 2023. https://www.cnn.com/2023/04/21/world/iyw-rufous-hummingbird-tipping-point-extinction-earth-da ↩

  64. English, Simon G.; Bishop, Christine A.; Wilson, Scott; Smith, Adam C. (15 September 2021). "Current contrasting population trends among North American hummingbirds". Scientific Reports. 11 (1): 18369. Bibcode:2021NatSR..1118369E. doi:10.1038/s41598-021-97889-x. ISSN 2045-2322. PMC 8443710. PMID 34526619. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8443710 ↩

  65. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  66. Chillag, Amy (21 April 2023). "These tiny creatures are losing their battle to survive. Here's what we can do to save them". CNN. Retrieved 22 April 2023. https://www.cnn.com/2023/04/21/world/iyw-rufous-hummingbird-tipping-point-extinction-earth-da ↩

  67. English, Simon G.; Bishop, Christine A.; Wilson, Scott; Smith, Adam C. (15 September 2021). "Current contrasting population trends among North American hummingbirds". Scientific Reports. 11 (1): 18369. Bibcode:2021NatSR..1118369E. doi:10.1038/s41598-021-97889-x. ISSN 2045-2322. PMC 8443710. PMID 34526619. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8443710 ↩

  68. Greig, Emma I.; Wood, Eric M.; Bonter, David N. (5 April 2017). "Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding". Proceedings of the Royal Society B: Biological Sciences. 284 (1852): 20170256. doi:10.1098/rspb.2017.0256. ISSN 0962-8452. PMC 5394677. PMID 28381617. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394677 ↩

  69. White, Richard (19 September 2015). "Hummingbird hawk moth, hummingbird and sunbird". Bird Ecology Study Group. Retrieved 8 March 2023. https://besgroup.org/2015/09/19/hummingbird-hawk-moth-hummingbird-and-sunbird/ ↩

  70. Prinzinger, R.; Schafer, T.; Schuchmann, K.L. (1992). "Energy metabolism, respiratory quotient and breathing parameters in two convergent small bird species : the fork-tailed sunbird Aethopyga christinae (Nectariniidae) and the chilean hummingbird Sephanoides sephanoides (Trochilidae)". Journal of Thermal Biology. 17 (2): 71–79. Bibcode:1992JTBio..17...71P. doi:10.1016/0306-4565(92)90001-V. /wiki/Bibcode_(identifier) ↩

  71. Moisset, Beatriz (2022). "Hummingbird moth (Hemaris spp.)". Forest Service, US Department of Agriculture. Retrieved 2 August 2022. https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/hummingbird_moth.shtml ↩

  72. White, Richard (19 September 2015). "Hummingbird hawk moth, hummingbird and sunbird". Bird Ecology Study Group. Retrieved 8 March 2023. https://besgroup.org/2015/09/19/hummingbird-hawk-moth-hummingbird-and-sunbird/ ↩

  73. Fjeldså, J.; Heynen, I. (1999). Genus Oreotrochilus. In: del Hoyo, J., A. Elliott, & J. Sargatal. eds. (1999). Handbook of the Birds of the World. Vol. 5. Barn-owls to Hummingbirds. Lynx Edicions, Barcelona. Lynx Edicions. pp. 623–624. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  74. Jaramillo, A.; Barros, R. (2010). "Species lists of birds for South American countries and territories: Chile". http://www.museum.lsu.edu/~Remsen/SACCListByCountry.xls ↩

  75. Salaman, P.; Donegan, T.; Caro, D. (2009). "Checklist to the Birds of Colombia 2009" (PDF). Conservation Colombiana. Fundación ProAves. Archived from the original (PDF) on 24 August 2009. https://web.archive.org/web/20090824105022/http://www.proaves.org/IMG/pdf/Aves_de_Colombia_2009-2.pdf ↩

  76. Freile, J. (2009). "Species lists of birds for South American countries and territories: Ecuador". http://www.museum.lsu.edu/~Remsen/SACCListByCountry.xls ↩

  77. Vigors, Nicholas Aylward (1825). "Observations on the natural affinities that connect the orders and families of birds". Transactions of the Linnean Society of London. 14 (3): 395–517 [463]. doi:10.1111/j.1095-8339.1823.tb00098.x. /wiki/Nicholas_Aylward_Vigors ↩

  78. Bock, Walter J. (1994). History and Nomenclature of Avian Family-Group Names. Bulletin of the American Museum of Natural History. Vol. 222. New York: American Museum of Natural History. pp. 143, 264. hdl:2246/830. http://digitallibrary.amnh.org/handle/2246/830 ↩

  79. Sibley, Charles Gald; Ahlquist, Jon Edward (1990). Phylogeny and classification of birds. New Haven, Conn.: Yale University Press. ↩

  80. Mayr, Gerald (March 2005). "Fossil hummingbirds of the Old World" (PDF). Biologist. 52 (1): 12–16. Archived from the original (PDF) on 27 September 2011. Retrieved 14 December 2009. https://web.archive.org/web/20110927045239/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/hummingbird_biologist.pdf ↩

  81. Gill, F.; Donsker, D.; Rasmussen, P. (29 January 2023). "IOC World Bird List (v 13.2), International Ornithological Committee". IOC World Bird List. Retrieved 5 March 2023. https://www.worldbirdnames.org/new/bow/hummingbirds ↩

  82. McGuire, J.; Witt, C.; Remsen, J.V.; Corl, A.; Rabosky, D.; Altshuler, D.; Dudley, R. (2014). "Molecular phylogenetics and the diversification of hummingbirds". Current Biology. 24 (8): 910–916. Bibcode:2014CBio...24..910M. doi:10.1016/j.cub.2014.03.016. PMID 24704078. https://doi.org/10.1016%2Fj.cub.2014.03.016 ↩

  83. McGuire, J.; Witt, C.; Remsen, J.V.; Corl, A.; Rabosky, D.; Altshuler, D.; Dudley, R. (2014). "Molecular phylogenetics and the diversification of hummingbirds". Current Biology. 24 (8): 910–916. Bibcode:2014CBio...24..910M. doi:10.1016/j.cub.2014.03.016. PMID 24704078. https://doi.org/10.1016%2Fj.cub.2014.03.016 ↩

  84. Gill, F.; Donsker, D.; Rasmussen, P. (29 January 2023). "IOC World Bird List (v 13.2), International Ornithological Committee". IOC World Bird List. Retrieved 5 March 2023. https://www.worldbirdnames.org/new/bow/hummingbirds ↩

  85. Mayr, Gerald (March 2005). "Fossil hummingbirds of the Old World" (PDF). Biologist. 52 (1): 12–16. Archived from the original (PDF) on 27 September 2011. Retrieved 14 December 2009. https://web.archive.org/web/20110927045239/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/hummingbird_biologist.pdf ↩

  86. Mayr, Gerald (2004). "Old World fossil record of modern-type hummingbirds". Science. 304 (5672): 861–864. Bibcode:2004Sci...304..861M. doi:10.1126/science.1096856. PMID 15131303. S2CID 6845608. /wiki/Bibcode_(identifier) ↩

  87. Bleiweiss, Robert; Kirsch, John A. W.; Matheus, Juan Carlos (1999). "DNA-DNA hybridization evidence for subfamily structure among hummingbirds" (PDF). Auk. 111 (1): 8–19. doi:10.2307/4088500. JSTOR 4088500. Archived from the original (PDF) on 25 July 2021. Retrieved 1 April 2013. https://web.archive.org/web/20210725122234/https://sora.unm.edu/sites/default/files/journals/auk/v111n01/p0008-p0019.pdf ↩

  88. Ksepka, Daniel T.; Clarke, Julia A.; Nesbitt, Sterling J.; Kulp, Felicia B.; Grande, Lance (2013). "Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes)". Proceedings of the Royal Society B. 280 (1761): 1761. doi:10.1098/rspb.2013.0580. PMC 3652446. PMID 23760643. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3652446 ↩

  89. McGuire, J.; Witt, C.; Remsen, J.V.; Corl, A.; Rabosky, D.; Altshuler, D.; Dudley, R. (2014). "Molecular phylogenetics and the diversification of hummingbirds". Current Biology. 24 (8): 910–916. Bibcode:2014CBio...24..910M. doi:10.1016/j.cub.2014.03.016. PMID 24704078. https://doi.org/10.1016%2Fj.cub.2014.03.016 ↩

  90. Mayr, Gerald (2004). "Old World fossil record of modern-type hummingbirds". Science. 304 (5672): 861–864. Bibcode:2004Sci...304..861M. doi:10.1126/science.1096856. PMID 15131303. S2CID 6845608. /wiki/Bibcode_(identifier) ↩

  91. Mayr, Gerald (1 January 2007). "New specimens of the early Oligocene Old World hummingbird Eurotrochilus inexpectatus". Journal of Ornithology. 148 (1): 105–111. Bibcode:2007JOrni.148..105M. doi:10.1007/s10336-006-0108-y. ISSN 2193-7206. S2CID 11821178. https://doi.org/10.1007/s10336-006-0108-y ↩

  92. Bochenski, Zygmunt; Bochenski, Zbigniew M. (1 April 2008). "An Old World hummingbird from the Oligocene: a new fossil from Polish Carpathians". Journal of Ornithology. 149 (2): 211–216. Bibcode:2008JOrni.149..211B. doi:10.1007/s10336-007-0261-y. ISSN 2193-7206. S2CID 22193761. https://doi.org/10.1007/s10336-007-0261-y ↩

  93. McGuire, J.; Witt, C.; Remsen, J.V.; Corl, A.; Rabosky, D.; Altshuler, D.; Dudley, R. (2014). "Molecular phylogenetics and the diversification of hummingbirds". Current Biology. 24 (8): 910–916. Bibcode:2014CBio...24..910M. doi:10.1016/j.cub.2014.03.016. PMID 24704078. https://doi.org/10.1016%2Fj.cub.2014.03.016 ↩

  94. "Hummingbirds' 22-million-year-old history of remarkable change is far from complete". ScienceDaily. 3 April 2014. Retrieved 30 September 2014. https://www.sciencedaily.com/releases/2014/04/140403132207.htm ↩

  95. McGuire, J.; Witt, C.; Remsen, J.V.; Corl, A.; Rabosky, D.; Altshuler, D.; Dudley, R. (2014). "Molecular phylogenetics and the diversification of hummingbirds". Current Biology. 24 (8): 910–916. Bibcode:2014CBio...24..910M. doi:10.1016/j.cub.2014.03.016. PMID 24704078. https://doi.org/10.1016%2Fj.cub.2014.03.016 ↩

  96. McGuire, J.A.; Witt, C.C.; Altshuler, D.L.; Remsen, J.V. (2007). "Phylogenetic systematics and biogeography of hummingbirds: Bayesian and maximum likelihood analyses of partitioned data and selection of an appropriate partitioning strategy". Systematic Biology. 56 (5): 837–856. doi:10.1080/10635150701656360. PMID 17934998. https://doi.org/10.1080%2F10635150701656360 ↩

  97. McGuire, Jimmy A.; Witt, Christopher C.; Remsen, J.V. Jr.; Dudley, R.; Altshuler, Douglas L. (2008). "A higher-level taxonomy for hummingbirds". Journal of Ornithology. 150 (1): 155–165. doi:10.1007/s10336-008-0330-x. ISSN 0021-8375. S2CID 1918245. /wiki/Doi_(identifier) ↩

  98. McGuire, J.A.; Witt, C.C.; Altshuler, D.L.; Remsen, J.V. (2007). "Phylogenetic systematics and biogeography of hummingbirds: Bayesian and maximum likelihood analyses of partitioned data and selection of an appropriate partitioning strategy". Systematic Biology. 56 (5): 837–856. doi:10.1080/10635150701656360. PMID 17934998. https://doi.org/10.1080%2F10635150701656360 ↩

  99. McGuire, J.; Witt, C.; Remsen, J.V.; Corl, A.; Rabosky, D.; Altshuler, D.; Dudley, R. (2014). "Molecular phylogenetics and the diversification of hummingbirds". Current Biology. 24 (8): 910–916. Bibcode:2014CBio...24..910M. doi:10.1016/j.cub.2014.03.016. PMID 24704078. https://doi.org/10.1016%2Fj.cub.2014.03.016 ↩

  100. Dickinson, E.C.; Remsen, J.V. Jr., eds. (2013). The Howard & Moore Complete Checklist of the Birds of the World. Vol. 1: Non-passerines (4th ed.). Eastbourne, UK: Aves Press. pp. 105–136. ISBN 978-0-9568611-0-8. 978-0-9568611-0-8 ↩

  101. McGuire, J.; Witt, C.; Remsen, J.V.; Corl, A.; Rabosky, D.; Altshuler, D.; Dudley, R. (2014). "Molecular phylogenetics and the diversification of hummingbirds". Current Biology. 24 (8): 910–916. Bibcode:2014CBio...24..910M. doi:10.1016/j.cub.2014.03.016. PMID 24704078. https://doi.org/10.1016%2Fj.cub.2014.03.016 ↩

  102. McGuire, Jimmy A.; Witt, Christopher C.; Remsen, J.V. Jr.; Dudley, R.; Altshuler, Douglas L. (2008). "A higher-level taxonomy for hummingbirds". Journal of Ornithology. 150 (1): 155–165. doi:10.1007/s10336-008-0330-x. ISSN 0021-8375. S2CID 1918245. /wiki/Doi_(identifier) ↩

  103. Bleiweiss, R.; Kirsch, J.A.; Matheus, J.C. (1997). "DNA hybridization evidence for the principal lineages of hummingbirds (Aves:Trochilidae)". Molecular Biology and Evolution. 14 (3): 325–343. doi:10.1093/oxfordjournals.molbev.a025767. PMID 9066799. https://doi.org/10.1093%2Foxfordjournals.molbev.a025767 ↩

  104. Dickinson & Remsen 2013, pp. 105–136. - Dickinson, E.C.; Remsen, J.V. Jr., eds. (2013). The Howard & Moore Complete Checklist of the Birds of the World. Vol. 1: Non-passerines (4th ed.). Eastbourne, UK: Aves Press. pp. 105–136. ISBN 978-0-9568611-0-8. ↩

  105. "Hummingbirds' 22-million-year-old history of remarkable change is far from complete". ScienceDaily. 3 April 2014. Retrieved 30 September 2014. https://www.sciencedaily.com/releases/2014/04/140403132207.htm ↩

  106. Baldwin, M.W.; Toda, Y.; Nakagita, T.; O'Connell, M.J.; Klasing, K.C.; Misaka, T.; Edwards, S.V.; Liberles, S. D. (2014). "Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor". Science. 345 (6199): 929–933. Bibcode:2014Sci...345..929B. doi:10.1126/science.1255097. PMC 4302410. PMID 25146290. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4302410 ↩

  107. Rico-Guevara, A.; Araya-Salas, M. (2015). "Bills as daggers? A test for sexually dimorphic weapons in a lekking hummingbird". Behavioral Ecology. 26 (1): 21–29. doi:10.1093/beheco/aru182. https://doi.org/10.1093%2Fbeheco%2Faru182 ↩

  108. "Hummingbirds' 22-million-year-old history of remarkable change is far from complete". ScienceDaily. 3 April 2014. Retrieved 30 September 2014. https://www.sciencedaily.com/releases/2014/04/140403132207.htm ↩

  109. "Hummingbirds' 22-million-year-old history of remarkable change is far from complete". ScienceDaily. 3 April 2014. Retrieved 30 September 2014. https://www.sciencedaily.com/releases/2014/04/140403132207.htm ↩

  110. Abrahamczyk, S.; Renner, S.S. (2015). "The temporal build-up of hummingbird/plant mutualisms in North America and temperate South America". BMC Evolutionary Biology. 15 (1): 104. Bibcode:2015BMCEE..15..104A. doi:10.1186/s12862-015-0388-z. PMC 4460853. PMID 26058608. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4460853 ↩

  111. Abrahamczyk, S.; Souto-Vilarós, D.; McGuire, J.A.; Renner, S.S. (2015). "Diversity and clade ages of West Indian hummingbirds and the largest plant clades dependent on them: a 5–9 Myr young mutualistic system". Biological Journal of the Linnean Society. 114 (4): 848–859. doi:10.1111/bij.12476. https://zenodo.org/record/890511 ↩

  112. Abrahamczyk, S.; Souto-Vilaros, D.; Renner, S. S. (2014). "Escape from extreme specialization: Passionflowers, bats and the sword-billed hummingbird". Proceedings of the Royal Society B: Biological Sciences. 281 (1795): 20140888. doi:10.1098/rspb.2014.0888. PMC 4213610. PMID 25274372. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4213610 ↩

  113. Stiles, Gary (1981). "Geographical aspects of bird flower coevolution, with particular reference to Central America" (PDF). Annals of the Missouri Botanical Garden. 68 (2): 323–351. Bibcode:1981AnMBG..68..323S. doi:10.2307/2398801. JSTOR 2398801. S2CID 87692272. https://www.biodiversitylibrary.org/pdf2/002816500087380.pdf ↩

  114. Maglianesi, M.A.; Blüthgen, N.; Böhning-Gaese, K. & Schleuning, M. (2014). "Morphological traits determine specialization and resource use in plant–hummingbird networks in the Neotropics". Ecology. 95 (12): 3325–334. Bibcode:2014Ecol...95.3325M. doi:10.1890/13-2261.1. https://www.researchgate.net/publication/268518487 ↩

  115. Abrahamczyk, Stefan; Poretschkin, Constantin & Renner, Susanne S. (2017). "Evolutionary flexibility in five hummingbird/plant mutualistic systems: testing temporal and geographic matching". Journal of Biogeography. 44 (8): 1847–855. Bibcode:2017JBiog..44.1847A. doi:10.1111/jbi.12962. S2CID 90399556. /wiki/Bibcode_(identifier) ↩

  116. Simon, Matt (10 July 2015). "Absurd Creature of the Week: The World's Tiniest Bird Weighs Less Than a Dime". Wired. Retrieved 8 March 2017. https://www.wired.com/2015/07/absurd-creature-of-the-week-bee-hummingbird ↩

  117. Dalsgaard, Bo; Martín González, Ana M.; Olesen, Jens M.; et al. (2009). "Plant-hummingbird interactions in the West Indies: Floral specialisation gradients associated with environment and hummingbird size". Oecologia. 159 (4): 757–766. Bibcode:2009Oecol.159..757D. doi:10.1007/s00442-008-1255-z. PMID 19132403. S2CID 35922888. /wiki/Bibcode_(identifier) ↩

  118. Rodríguez-Gironés, M.A. & Santamaría, L. (2004). "Why are so many bird flowers red?". PLOS Biology. 2 (10): e350. doi:10.1371/journal.pbio.0020350. PMC 521733. PMID 15486585. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC521733 ↩

  119. Altschuler, D. L. (2003). "Flower color, hummingbird pollination, and habitat irradiance in four Neotropical forests". Biotropica. 35 (3): 344–355. doi:10.1646/02113. S2CID 55929111. /wiki/Biotropica ↩

  120. Nicolson, S.W. & Fleming, P.A. (2003). "Nectar as food for birds: the physiological consequences of drinking dilute sugar solutions". Plant Systematics and Evolution. 238 (1–4): 139–153. Bibcode:2003PSyEv.238..139N. doi:10.1007/s00606-003-0276-7. S2CID 23401164. http://researchrepository.murdoch.edu.au/id/eprint/4725 ↩

  121. Junker, Robert R.; Blüthgen, Nico; Brehm, Tanja; Binkenstein, Julia; Paulus, Justina; Martin Schaefer, H. & Stang, Martina (13 December 2012). "Specialization on traits as basis for the niche-breadth of flower visitors and as structuring mechanism of ecological networks". Functional Ecology. 27 (2): 329–341. doi:10.1111/1365-2435.12005. https://doi.org/10.1111%2F1365-2435.12005 ↩

  122. Junker, Robert R.; Blüthgen, Nico; Brehm, Tanja; Binkenstein, Julia; Paulus, Justina; Martin Schaefer, H. & Stang, Martina (13 December 2012). "Specialization on traits as basis for the niche-breadth of flower visitors and as structuring mechanism of ecological networks". Functional Ecology. 27 (2): 329–341. doi:10.1111/1365-2435.12005. https://doi.org/10.1111%2F1365-2435.12005 ↩

  123. Martín González, Ana M.; Dalsgaard, Bo; et al. (30 July 2015). "The macroecology of phylogenetically structured hummingbird-plant networks". Global Ecology and Biogeography. 24 (11): 1212–224. Bibcode:2015GloEB..24.1212M. doi:10.1111/geb.12355. hdl:10026.1/3407. /wiki/Bibcode_(identifier) ↩

  124. Colwell, Robert K. (1 November 2000). "Rensch's Rule Crosses the Line: Convergent Allometry of Sexual Size Dimorphism in Hummingbirds and Flower Mites". The American Naturalist. 156 (5): 495–510. Bibcode:2000ANat..156..495C. doi:10.1086/303406. PMID 29587514. S2CID 4401233. /wiki/Bibcode_(identifier) ↩

  125. Lisle, Stephen P. De; Rowe, Locke (1 November 2013). "Correlated Evolution of Allometry and Sexual Dimorphism across Higher Taxa". The American Naturalist. 182 (5): 630–639. Bibcode:2013ANat..182..630D. doi:10.1086/673282. PMID 24107370. S2CID 25612107. /wiki/Bibcode_(identifier) ↩

  126. Lisle, Stephen P. De; Rowe, Locke (1 November 2013). "Correlated Evolution of Allometry and Sexual Dimorphism across Higher Taxa". The American Naturalist. 182 (5): 630–639. Bibcode:2013ANat..182..630D. doi:10.1086/673282. PMID 24107370. S2CID 25612107. /wiki/Bibcode_(identifier) ↩

  127. Berns, Chelsea M.; Adams, Dean C. (11 November 2012). "Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds". Evolutionary Biology. 40 (2): 246–260. doi:10.1007/s11692-012-9206-3. ISSN 0071-3260. S2CID 276492. /wiki/Doi_(identifier) ↩

  128. Berns, Chelsea M.; Adams, Dean C. (11 November 2012). "Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds". Evolutionary Biology. 40 (2): 246–260. doi:10.1007/s11692-012-9206-3. ISSN 0071-3260. S2CID 276492. /wiki/Doi_(identifier) ↩

  129. Berns, Chelsea M.; Adams, Dean C. (11 November 2012). "Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds". Evolutionary Biology. 40 (2): 246–260. doi:10.1007/s11692-012-9206-3. ISSN 0071-3260. S2CID 276492. /wiki/Doi_(identifier) ↩

  130. Berns, Chelsea M.; Adams, Dean C. (11 November 2012). "Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds". Evolutionary Biology. 40 (2): 246–260. doi:10.1007/s11692-012-9206-3. ISSN 0071-3260. S2CID 276492. /wiki/Doi_(identifier) ↩

  131. Temeles, Ethan J.; Miller, Jill S.; Rifkin, Joanna L. (12 April 2010). "Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation". Philosophical Transactions of the Royal Society of London B: Biological Sciences. 365 (1543): 1053–063. doi:10.1098/rstb.2009.0284. ISSN 0962-8436. PMC 2830232. PMID 20194168. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830232 ↩

  132. Berns, Chelsea M.; Adams, Dean C. (11 November 2012). "Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds". Evolutionary Biology. 40 (2): 246–260. doi:10.1007/s11692-012-9206-3. ISSN 0071-3260. S2CID 276492. /wiki/Doi_(identifier) ↩

  133. Colwell, Robert K. (1 November 2000). "Rensch's Rule Crosses the Line: Convergent Allometry of Sexual Size Dimorphism in Hummingbirds and Flower Mites". The American Naturalist. 156 (5): 495–510. Bibcode:2000ANat..156..495C. doi:10.1086/303406. PMID 29587514. S2CID 4401233. /wiki/Bibcode_(identifier) ↩

  134. Colwell, Robert K. (1 November 2000). "Rensch's Rule Crosses the Line: Convergent Allometry of Sexual Size Dimorphism in Hummingbirds and Flower Mites". The American Naturalist. 156 (5): 495–510. Bibcode:2000ANat..156..495C. doi:10.1086/303406. PMID 29587514. S2CID 4401233. /wiki/Bibcode_(identifier) ↩

  135. Colwell, Robert K. (1 November 2000). "Rensch's Rule Crosses the Line: Convergent Allometry of Sexual Size Dimorphism in Hummingbirds and Flower Mites". The American Naturalist. 156 (5): 495–510. Bibcode:2000ANat..156..495C. doi:10.1086/303406. PMID 29587514. S2CID 4401233. /wiki/Bibcode_(identifier) ↩

  136. Temeles, Ethan J.; Miller, Jill S.; Rifkin, Joanna L. (12 April 2010). "Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation". Philosophical Transactions of the Royal Society of London B: Biological Sciences. 365 (1543): 1053–063. doi:10.1098/rstb.2009.0284. ISSN 0962-8436. PMC 2830232. PMID 20194168. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830232 ↩

  137. Temeles, Ethan J.; Miller, Jill S.; Rifkin, Joanna L. (12 April 2010). "Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation". Philosophical Transactions of the Royal Society of London B: Biological Sciences. 365 (1543): 1053–063. doi:10.1098/rstb.2009.0284. ISSN 0962-8436. PMC 2830232. PMID 20194168. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830232 ↩

  138. Lisle, Stephen P. De; Rowe, Locke (1 November 2013). "Correlated Evolution of Allometry and Sexual Dimorphism across Higher Taxa". The American Naturalist. 182 (5): 630–639. Bibcode:2013ANat..182..630D. doi:10.1086/673282. PMID 24107370. S2CID 25612107. /wiki/Bibcode_(identifier) ↩

  139. Berns, Chelsea M.; Adams, Dean C. (11 November 2012). "Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds". Evolutionary Biology. 40 (2): 246–260. doi:10.1007/s11692-012-9206-3. ISSN 0071-3260. S2CID 276492. /wiki/Doi_(identifier) ↩

  140. Temeles, Ethan J.; Miller, Jill S.; Rifkin, Joanna L. (12 April 2010). "Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation". Philosophical Transactions of the Royal Society of London B: Biological Sciences. 365 (1543): 1053–063. doi:10.1098/rstb.2009.0284. ISSN 0962-8436. PMC 2830232. PMID 20194168. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830232 ↩

  141. Temeles, Ethan J.; Miller, Jill S.; Rifkin, Joanna L. (12 April 2010). "Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation". Philosophical Transactions of the Royal Society of London B: Biological Sciences. 365 (1543): 1053–063. doi:10.1098/rstb.2009.0284. ISSN 0962-8436. PMC 2830232. PMID 20194168. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830232 ↩

  142. Temeles, Ethan J.; Miller, Jill S.; Rifkin, Joanna L. (12 April 2010). "Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation". Philosophical Transactions of the Royal Society of London B: Biological Sciences. 365 (1543): 1053–063. doi:10.1098/rstb.2009.0284. ISSN 0962-8436. PMC 2830232. PMID 20194168. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830232 ↩

  143. Venable, G.X.; Gahm, K.; Prum, R.O. (June 2022). "Hummingbird plumage color diversity exceeds the known gamut of all other birds". Communications Biology. 5 (1): 576. doi:10.1038/s42003-022-03518-2. PMC 9226176. PMID 35739263. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9226176 ↩

  144. Venable, G.X.; Gahm, K.; Prum, R.O. (June 2022). "Hummingbird plumage color diversity exceeds the known gamut of all other birds". Communications Biology. 5 (1): 576. doi:10.1038/s42003-022-03518-2. PMC 9226176. PMID 35739263. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9226176 ↩

  145. Venable, G.X.; Gahm, K.; Prum, R.O. (June 2022). "Hummingbird plumage color diversity exceeds the known gamut of all other birds". Communications Biology. 5 (1): 576. doi:10.1038/s42003-022-03518-2. PMC 9226176. PMID 35739263. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9226176 ↩

  146. Venable, G.X.; Gahm, K.; Prum, R.O. (June 2022). "Hummingbird plumage color diversity exceeds the known gamut of all other birds". Communications Biology. 5 (1): 576. doi:10.1038/s42003-022-03518-2. PMC 9226176. PMID 35739263. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9226176 ↩

  147. "Hummingbird characteristics". learner.org. Annenberg Learner, The Annenberg Foundation. 2015. Archived from the original on 11 November 2016. Retrieved 30 August 2010. https://web.archive.org/web/20161111085045/http://learner.org/jnorth/search/HummerNotes1.html ↩

  148. Venable, G.X.; Gahm, K.; Prum, R.O. (June 2022). "Hummingbird plumage color diversity exceeds the known gamut of all other birds". Communications Biology. 5 (1): 576. doi:10.1038/s42003-022-03518-2. PMC 9226176. PMID 35739263. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9226176 ↩

  149. Williamson S (2001). A Field Guide to Hummingbirds of North America. Section: Plumage and Molt. Houghton Mifflin Harcourt. pp. 13–18. ISBN 978-0-618-02496-4. 978-0-618-02496-4 ↩

  150. Williamson S (2001). A Field Guide to Hummingbirds of North America. Section: Plumage and Molt. Houghton Mifflin Harcourt. pp. 13–18. ISBN 978-0-618-02496-4. 978-0-618-02496-4 ↩

  151. Williamson S (2001). A Field Guide to Hummingbirds of North America. Section: Plumage and Molt. Houghton Mifflin Harcourt. pp. 13–18. ISBN 978-0-618-02496-4. 978-0-618-02496-4 ↩

  152. Venable, G.X.; Gahm, K.; Prum, R.O. (June 2022). "Hummingbird plumage color diversity exceeds the known gamut of all other birds". Communications Biology. 5 (1): 576. doi:10.1038/s42003-022-03518-2. PMC 9226176. PMID 35739263. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9226176 ↩

  153. "Hummingbird characteristics". learner.org. Annenberg Learner, The Annenberg Foundation. 2015. Archived from the original on 11 November 2016. Retrieved 30 August 2010. https://web.archive.org/web/20161111085045/http://learner.org/jnorth/search/HummerNotes1.html ↩

  154. Williamson S (2001). A Field Guide to Hummingbirds of North America. Section: Plumage and Molt. Houghton Mifflin Harcourt. pp. 13–18. ISBN 978-0-618-02496-4. 978-0-618-02496-4 ↩

  155. Williamson S (2001). A Field Guide to Hummingbirds of North America. Section: Plumage and Molt. Houghton Mifflin Harcourt. pp. 13–18. ISBN 978-0-618-02496-4. 978-0-618-02496-4 ↩

  156. Hamilton, W.J. (1965). "Sun-oriented display of the Anna's hummingbird" (PDF). The Wilson Bulletin. 77 (1). https://sora.unm.edu/sites/default/files/journals/wilson/v077n01/p0038-p0044.pdf ↩

  157. Meadows, M.G.; Roudybush, T.E.; McGraw, K.J. (2012). "Dietary protein level affects iridescent coloration in Anna's hummingbirds, Calypte anna". Journal of Experimental Biology. 215 (16): 2742–750. Bibcode:2012JExpB.215.2742M. doi:10.1242/jeb.069351. PMC 3404802. PMID 22837446. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3404802 ↩

  158. Meadows, M.G.; Roudybush, T.E.; McGraw, K.J. (2012). "Dietary protein level affects iridescent coloration in Anna's hummingbirds, Calypte anna". Journal of Experimental Biology. 215 (16): 2742–750. Bibcode:2012JExpB.215.2742M. doi:10.1242/jeb.069351. PMC 3404802. PMID 22837446. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3404802 ↩

  159. Hightower, Ben J.; Wijnings, Patrick W.A.; Scholte, Rick; et al. (16 March 2021). "How oscillating aerodynamic forces explain the timbre of the hummingbird's hum and other animals in flapping flight". eLife. 10: e63107. doi:10.7554/elife.63107. ISSN 2050-084X. PMC 8055270. PMID 33724182. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8055270 ↩

  160. Hightower, Ben J.; Wijnings, Patrick W.A.; Scholte, Rick; et al. (16 March 2021). "How oscillating aerodynamic forces explain the timbre of the hummingbird's hum and other animals in flapping flight". eLife. 10: e63107. doi:10.7554/elife.63107. ISSN 2050-084X. PMC 8055270. PMID 33724182. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8055270 ↩

  161. Hightower, Ben J.; Wijnings, Patrick W.A.; Scholte, Rick; et al. (16 March 2021). "How oscillating aerodynamic forces explain the timbre of the hummingbird's hum and other animals in flapping flight". eLife. 10: e63107. doi:10.7554/elife.63107. ISSN 2050-084X. PMC 8055270. PMID 33724182. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8055270 ↩

  162. Eindhoven University of Technology (16 March 2021). "New measurement technique unravels what gives hummingbird wings their characteristic sound". Phys.org. Retrieved 13 May 2021. https://phys.org/news/2021-03-technique-unravels-hummingbird-wings-characteristic.html ↩

  163. Hightower, Ben J.; Wijnings, Patrick W.A.; Scholte, Rick; et al. (16 March 2021). "How oscillating aerodynamic forces explain the timbre of the hummingbird's hum and other animals in flapping flight". eLife. 10: e63107. doi:10.7554/elife.63107. ISSN 2050-084X. PMC 8055270. PMID 33724182. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8055270 ↩

  164. Eindhoven University of Technology (16 March 2021). "New measurement technique unravels what gives hummingbird wings their characteristic sound". Phys.org. Retrieved 13 May 2021. https://phys.org/news/2021-03-technique-unravels-hummingbird-wings-characteristic.html ↩

  165. Ingersoll, Rivers; Lentink, David (15 October 2018). "How the hummingbird wingbeat is tuned for efficient hovering". Journal of Experimental Biology. 221 (20). Bibcode:2018JExpB.221B8228I. doi:10.1242/jeb.178228. ISSN 1477-9145. PMID 30323114. https://doi.org/10.1242%2Fjeb.178228 ↩

  166. Ocampo, Diego; Barrantes, Gilbert; Uy, J. Albert C. (27 September 2018). "Morphological adaptations for relatively larger brains in hummingbird skulls". Ecology and Evolution. 8 (21): 10482–10488. Bibcode:2018EcoEv...810482O. doi:10.1002/ece3.4513. ISSN 2045-7758. PMC 6238128. PMID 30464820. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6238128 ↩

  167. Lisney, T.J.; Wylie, D.R.; Kolominsky, J.; Iwaniuk, A.N. (2015). "Eye morphology and retinal topography in hummingbirds (Trochilidae Aves)". Brain, Behavior and Evolution. 86 (3–4): 176–190. doi:10.1159/000441834. PMID 26587582. https://www.karger.com/Article/FullText/441834 ↩

  168. Lisney, T.J.; Wylie, D.R.; Kolominsky, J.; Iwaniuk, A.N. (2015). "Eye morphology and retinal topography in hummingbirds (Trochilidae Aves)". Brain, Behavior and Evolution. 86 (3–4): 176–190. doi:10.1159/000441834. PMID 26587582. https://www.karger.com/Article/FullText/441834 ↩

  169. Lisney, T.J.; Wylie, D.R.; Kolominsky, J.; Iwaniuk, A.N. (2015). "Eye morphology and retinal topography in hummingbirds (Trochilidae Aves)". Brain, Behavior and Evolution. 86 (3–4): 176–190. doi:10.1159/000441834. PMID 26587582. https://www.karger.com/Article/FullText/441834 ↩

  170. Iwaniuk, A.N.; Wylie, D.R. (2007). "Neural specialization for hovering in hummingbirds: hypertrophy of the pretectal nucleus Lentiformis mesencephali" (PDF). Journal of Comparative Neurology. 500 (2): 211–221. doi:10.1002/cne.21098. PMID 17111358. S2CID 15678218. http://www.psych.ualberta.ca/~dwylie/Iwaniuk%20and%20Wylie%20JCN%202007.pdf ↩

  171. Gaede, A.H.; Goller, B.; Lam, J.P.; Wylie, D.R.; Altshuler, D.L. (2017). "Neurons responsive to global visual motion have unique tuning properties in hummingbirds". Current Biology. 27 (2): 279–285. Bibcode:2017CBio...27..279G. doi:10.1016/j.cub.2016.11.041. PMID 28065606. S2CID 28314419. https://doi.org/10.1016%2Fj.cub.2016.11.041 ↩

  172. Gaede, A.H.; Goller, B.; Lam, J.P.; Wylie, D.R.; Altshuler, D.L. (2017). "Neurons responsive to global visual motion have unique tuning properties in hummingbirds". Current Biology. 27 (2): 279–285. Bibcode:2017CBio...27..279G. doi:10.1016/j.cub.2016.11.041. PMID 28065606. S2CID 28314419. https://doi.org/10.1016%2Fj.cub.2016.11.041 ↩

  173. "Hummingbirds see motion in an unexpected way". ScienceDaily. 5 January 2017. Retrieved 24 April 2017. https://www.sciencedaily.com/releases/2017/01/170105123115.htm ↩

  174. Stoddard, M.C.; Eyster, H.N.; Hogan, B.G.; et al. (15 June 2020). "Wild hummingbirds discriminate nonspectral colors". Proceedings of the National Academy of Sciences. 117 (26): 15112–122. Bibcode:2020PNAS..11715112S. doi:10.1073/pnas.1919377117. ISSN 0027-8424. PMC 7334476. PMID 32541035. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7334476 ↩

  175. Stoddard, M.C.; Eyster, H.N.; Hogan, B.G.; et al. (15 June 2020). "Wild hummingbirds discriminate nonspectral colors". Proceedings of the National Academy of Sciences. 117 (26): 15112–122. Bibcode:2020PNAS..11715112S. doi:10.1073/pnas.1919377117. ISSN 0027-8424. PMC 7334476. PMID 32541035. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7334476 ↩

  176. Gaede, A.H.; Goller, B.; Lam, J.P.; Wylie, D.R.; Altshuler, D.L. (2017). "Neurons responsive to global visual motion have unique tuning properties in hummingbirds". Current Biology. 27 (2): 279–285. Bibcode:2017CBio...27..279G. doi:10.1016/j.cub.2016.11.041. PMID 28065606. S2CID 28314419. https://doi.org/10.1016%2Fj.cub.2016.11.041 ↩

  177. "Hummingbirds see motion in an unexpected way". ScienceDaily. 5 January 2017. Retrieved 24 April 2017. https://www.sciencedaily.com/releases/2017/01/170105123115.htm ↩

  178. Goller, B.; Altshuler, D.L. (2014). "Hummingbirds control hovering flight by stabilizing visual motion". Proceedings of the National Academy of Sciences. 111 (51): 18375–380. Bibcode:2014PNAS..11118375G. doi:10.1073/pnas.1415975111. PMC 4280641. PMID 25489117. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4280641 ↩

  179. Goller, B.; Altshuler, D.L. (2014). "Hummingbirds control hovering flight by stabilizing visual motion". Proceedings of the National Academy of Sciences. 111 (51): 18375–380. Bibcode:2014PNAS..11118375G. doi:10.1073/pnas.1415975111. PMC 4280641. PMID 25489117. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4280641 ↩

  180. Gaede, A.H.; Goller, B.; Lam, J.P.; Wylie, D.R.; Altshuler, D.L. (2017). "Neurons responsive to global visual motion have unique tuning properties in hummingbirds". Current Biology. 27 (2): 279–285. Bibcode:2017CBio...27..279G. doi:10.1016/j.cub.2016.11.041. PMID 28065606. S2CID 28314419. https://doi.org/10.1016%2Fj.cub.2016.11.041 ↩

  181. Duque, F.G.; Carruth, L.L. (2022). "Vocal communication in hummingbirds". Brain, Behavior and Evolution (Review). 97 (3–4): 241–252. doi:10.1159/000522148. PMID 35073546. S2CID 246278322. https://www.karger.com/Article/FullText/522148 ↩

  182. "Song sounds of various hummingbird species". All About Birds. The Cornell Lab of Ornithology, Cornell University, Ithaca, New York. 2015. Retrieved 25 June 2016. https://www.allaboutbirds.org/guide/browse.aspx?shape=37,11 ↩

  183. Duque, F.G.; Carruth, L.L. (2022). "Vocal communication in hummingbirds". Brain, Behavior and Evolution (Review). 97 (3–4): 241–252. doi:10.1159/000522148. PMID 35073546. S2CID 246278322. https://www.karger.com/Article/FullText/522148 ↩

  184. Duque, F.G.; Carruth, L.L. (2022). "Vocal communication in hummingbirds". Brain, Behavior and Evolution (Review). 97 (3–4): 241–252. doi:10.1159/000522148. PMID 35073546. S2CID 246278322. https://www.karger.com/Article/FullText/522148 ↩

  185. Duque, F.G.; Carruth, L.L. (2022). "Vocal communication in hummingbirds". Brain, Behavior and Evolution (Review). 97 (3–4): 241–252. doi:10.1159/000522148. PMID 35073546. S2CID 246278322. https://www.karger.com/Article/FullText/522148 ↩

  186. Duque, F.G.; Carruth, L.L. (2022). "Vocal communication in hummingbirds". Brain, Behavior and Evolution (Review). 97 (3–4): 241–252. doi:10.1159/000522148. PMID 35073546. S2CID 246278322. https://www.karger.com/Article/FullText/522148 ↩

  187. Pytte, C.L.; Ficken, M.S.; Moiseff, A. (2004). "Ultrasonic singing by the blue-throated hummingbird: A comparison between production and perception". Journal of Comparative Physiology A. 190 (8): 665–673. doi:10.1007/s00359-004-0525-4. PMID 15164219. S2CID 7231117. https://www.researchgate.net/publication/8542654 ↩

  188. Pytte, C.L.; Ficken, M.S.; Moiseff, A. (2004). "Ultrasonic singing by the blue-throated hummingbird: A comparison between production and perception". Journal of Comparative Physiology A. 190 (8): 665–673. doi:10.1007/s00359-004-0525-4. PMID 15164219. S2CID 7231117. https://www.researchgate.net/publication/8542654 ↩

  189. Pytte, C.L.; Ficken, M.S.; Moiseff, A. (2004). "Ultrasonic singing by the blue-throated hummingbird: A comparison between production and perception". Journal of Comparative Physiology A. 190 (8): 665–673. doi:10.1007/s00359-004-0525-4. PMID 15164219. S2CID 7231117. https://www.researchgate.net/publication/8542654 ↩

  190. Duque, F.G.; Carruth, L.L. (2022). "Vocal communication in hummingbirds". Brain, Behavior and Evolution (Review). 97 (3–4): 241–252. doi:10.1159/000522148. PMID 35073546. S2CID 246278322. https://www.karger.com/Article/FullText/522148 ↩

  191. Duque, F.G.; Rodríguez-Saltos, C.A.; Wilczynsk, W. (September 2018). "High-frequency vocalizations in Andean hummingbirds". Current Biology. 28 (17): R927 – R928. Bibcode:2018CBio...28.R927D. doi:10.1016/j.cub.2018.07.058. PMID 30205060. S2CID 52188456. https://doi.org/10.1016%2Fj.cub.2018.07.058 ↩

  192. Monte, Amanda; Cerwenka, Alexander F.; Ruthensteiner, Bernhard; Gahr, Manfred; Düring, Daniel N. (6 July 2020). "The hummingbird syrinx morphome: a detailed three-dimensional description of the black jacobin's vocal organ". BMC Zoology. 5 (1): 7. doi:10.1186/s40850-020-00057-3. hdl:20.500.11850/429165. ISSN 2056-3132. S2CID 220509046. https://doi.org/10.1186%2Fs40850-020-00057-3 ↩

  193. Monte, Amanda; Cerwenka, Alexander F.; Ruthensteiner, Bernhard; Gahr, Manfred; Düring, Daniel N. (6 July 2020). "The hummingbird syrinx morphome: a detailed three-dimensional description of the black jacobin's vocal organ". BMC Zoology. 5 (1): 7. doi:10.1186/s40850-020-00057-3. hdl:20.500.11850/429165. ISSN 2056-3132. S2CID 220509046. https://doi.org/10.1186%2Fs40850-020-00057-3 ↩

  194. Riede, Tobias; Olson, Christopher R. (6 February 2020). "The vocal organ of hummingbirds shows convergence with songbirds". Scientific Reports. 10 (1): 2007. Bibcode:2020NatSR..10.2007R. doi:10.1038/s41598-020-58843-5. ISSN 2045-2322. PMC 7005288. PMID 32029812. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7005288 ↩

  195. Jarvis, Erich D.; Ribeiro, Sidarta; da Silva, Maria Luisa; Ventura, Dora; Vielliard, Jacques; Mello, Claudio V. (2000). "Behaviourally driven gene expression reveals song nuclei in hummingbird brain". Nature. 406 (6796): 628–632. Bibcode:2000Natur.406..628J. doi:10.1038/35020570. PMC 2531203. PMID 10949303. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2531203 ↩

  196. Gahr M. (2000). "Neural song control system of hummingbirds: comparison to swifts, vocal learning (Songbirds) and nonlearning (Suboscines) passerines, and vocal learning (Budgerigars) and nonlearning (Dove, owl, gull, quail, chicken) nonpasserines". J Comp Neurol. 486 (2): 182–196. doi:10.1002/1096-9861(20001016)426:2<182::AID-CNE2>3.0.CO;2-M. PMID 10982462. S2CID 10763166. /wiki/Doi_(identifier) ↩

  197. Jarvis, Erich D.; Ribeiro, Sidarta; da Silva, Maria Luisa; Ventura, Dora; Vielliard, Jacques; Mello, Claudio V. (2000). "Behaviourally driven gene expression reveals song nuclei in hummingbird brain". Nature. 406 (6796): 628–632. Bibcode:2000Natur.406..628J. doi:10.1038/35020570. PMC 2531203. PMID 10949303. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2531203 ↩

  198. Jarvis, Erich D.; Ribeiro, Sidarta; da Silva, Maria Luisa; Ventura, Dora; Vielliard, Jacques; Mello, Claudio V. (2000). "Behaviourally driven gene expression reveals song nuclei in hummingbird brain". Nature. 406 (6796): 628–632. Bibcode:2000Natur.406..628J. doi:10.1038/35020570. PMC 2531203. PMID 10949303. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2531203 ↩

  199. Renne, Paul R.; Deino, Alan L.; Hilgen, Frederik J.; et al. (7 February 2013). "Time Scales of Critical Events Around the Cretaceous-Paleogene Boundary" (PDF). Science. 339 (6120): 684–687. Bibcode:2013Sci...339..684R. doi:10.1126/science.1230492. PMID 23393261. S2CID 6112274. Archived from the original (PDF) on 7 February 2017. Retrieved 1 April 2018. https://web.archive.org/web/20170207164818/http://www.cugb.edu.cn/uploadCms/file/20600/20131028144132060.pdf ↩

  200. Duque, F.G.; Rodríguez-Saltos, C.A.; Wilczynsk, W. (September 2018). "High-frequency vocalizations in Andean hummingbirds". Current Biology. 28 (17): R927 – R928. Bibcode:2018CBio...28.R927D. doi:10.1016/j.cub.2018.07.058. PMID 30205060. S2CID 52188456. https://doi.org/10.1016%2Fj.cub.2018.07.058 ↩

  201. Duque, F.G.; Rodríguez-Saltos, C.A.; Wilczynsk, W. (September 2018). "High-frequency vocalizations in Andean hummingbirds". Current Biology. 28 (17): R927 – R928. Bibcode:2018CBio...28.R927D. doi:10.1016/j.cub.2018.07.058. PMID 30205060. S2CID 52188456. https://doi.org/10.1016%2Fj.cub.2018.07.058 ↩

  202. Duque, F.G.; Carruth, L.L. (2022). "Vocal communication in hummingbirds". Brain, Behavior and Evolution (Review). 97 (3–4): 241–252. doi:10.1159/000522148. PMID 35073546. S2CID 246278322. https://www.karger.com/Article/FullText/522148 ↩

  203. Hargrove, J.L. (2005). "Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds". Nutrition Journal. 4: 36. doi:10.1186/1475-2891-4-36. PMC 1325055. PMID 16351726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325055 ↩

  204. Altshuler, D.L.; Dudley, R. (2002). "The ecological and evolutionary interface of hummingbird flight physiology". The Journal of Experimental Biology. 205 (Pt 16): 2325–336. Bibcode:2002JExpB.205.2325A. doi:10.1242/jeb.205.16.2325. PMID 12124359. https://journals.biologists.com/jeb/article/205/16/2325/9117/The-ecological-and-evolutionary-interface-of ↩

  205. Suarez, R.K. (1992). "Hummingbird flight: Sustaining the highest mass-specific metabolic rates among vertebrates". Experientia. 48 (6): 565–570. doi:10.1007/bf01920240. PMID 1612136. S2CID 21328995. /wiki/Doi_(identifier) ↩

  206. Suarez R.K.; Lighton J.R.; Brown G.S.; Mathieu-Costello O. (June 1991). "Mitochondrial respiration in hummingbird flight muscles". Proceedings of the National Academy of Sciences of the United States of America. 88 (11): 4870–3. Bibcode:1991PNAS...88.4870S. doi:10.1073/pnas.88.11.4870. PMC 51768. PMID 2052568. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC51768 ↩

  207. Welch, K.C. Jr.; Chen, C.C. (2014). "Sugar flux through the flight muscles of hovering vertebrate nectarivores: A review". Journal of Comparative Physiology B. 184 (8): 945–959. doi:10.1007/s00360-014-0843-y. PMID 25031038. S2CID 11109453. /wiki/Doi_(identifier) ↩

  208. Suarez, R.K.; Lighton, J.R.; Moyes, C.D.; et al. (1 December 1990). "Fuel selection in rufous hummingbirds: ecological implications of metabolic biochemistry". Proceedings of the National Academy of Sciences of the United States of America. 87 (23): 9207–10. Bibcode:1990PNAS...87.9207S. doi:10.1073/pnas.87.23.9207. PMC 55133. PMID 2251266. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC55133 ↩

  209. Barlett, Paige (2018). "Fueling the hummingbird's extreme biology". Johns Hopkins Medicine. Archived from the original on 22 March 2023. Retrieved 27 March 2023. https://web.archive.org/web/20230322213148/https://www.hopkinsmedicine.org/research/advancements-in-research/fundamentals/in-depth/fueling-the-hummingbirds-extreme-biology ↩

  210. Campbell, Don (3 December 2013). "Hummingbird metabolism unique in burning glucose and fructose equally". University of Toronto - Scarborough. Retrieved 27 March 2023. https://utsc.utoronto.ca/news-events/archived/hummingbird-metabolism-unique-burning-glucose-and-fructose-equally ↩

  211. Chen, Chris Chin Wah; Welch, Kenneth Collins (2014). "Hummingbirds can fuel expensive hovering flight completely with either exogenous glucose or fructose". Functional Ecology. 28 (3): 589–600. Bibcode:2014FuEco..28..589C. doi:10.1111/1365-2435.12202. https://doi.org/10.1111%2F1365-2435.12202 ↩

  212. Welch, K.C. Jr.; Suarez, R.K. (2007). "Oxidation rate and turnover of ingested sugar in hovering Anna's (Calypte anna) and rufous (Selasphorus rufus) hummingbirds". Journal of Experimental Biology. 210 (Pt 12): 2154–162. Bibcode:2007JExpB.210.2154W. doi:10.1242/jeb.005363. PMID 17562889. https://doi.org/10.1242%2Fjeb.005363 ↩

  213. Suarez, Raul; Welch, Kenneth (12 July 2017). "Sugar metabolism in hummingbirds and nectar bats". Nutrients. 9 (7): 743. doi:10.3390/nu9070743. ISSN 2072-6643. PMC 5537857. PMID 28704953. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537857 ↩

  214. Callier, Viviane (24 February 2023). "Evolution Turns These Knobs to Make a Hummingbird Hyperquick and a Cavefish Sluggishly Slow". Scientific American. Retrieved 27 February 2023. https://www.scientificamerican.com/article/evolution-turns-these-knobs-to-make-a-hummingbird-hyperquick-and-a-cavefish-sluggishly-slow/ ↩

  215. Osipova, Ekaterina; Barsacchi, Rico; Brown, Tom; et al. (13 January 2023). "Loss of a gluconeogenic muscle enzyme contributed to adaptive metabolic traits in hummingbirds". Science. 379 (6628): 185–190. Bibcode:2023Sci...379..185O. doi:10.1126/science.abn7050. ISSN 0036-8075. PMID 36634192. S2CID 255749672. https://www.science.org/doi/10.1126/science.abn7050 ↩

  216. Callier, Viviane (24 February 2023). "Evolution Turns These Knobs to Make a Hummingbird Hyperquick and a Cavefish Sluggishly Slow". Scientific American. Retrieved 27 February 2023. https://www.scientificamerican.com/article/evolution-turns-these-knobs-to-make-a-hummingbird-hyperquick-and-a-cavefish-sluggishly-slow/ ↩

  217. Osipova, Ekaterina; Barsacchi, Rico; Brown, Tom; et al. (13 January 2023). "Loss of a gluconeogenic muscle enzyme contributed to adaptive metabolic traits in hummingbirds". Science. 379 (6628): 185–190. Bibcode:2023Sci...379..185O. doi:10.1126/science.abn7050. ISSN 0036-8075. PMID 36634192. S2CID 255749672. https://www.science.org/doi/10.1126/science.abn7050 ↩

  218. Chen, Chris Chin Wah; Welch, Kenneth Collins (2014). "Hummingbirds can fuel expensive hovering flight completely with either exogenous glucose or fructose". Functional Ecology. 28 (3): 589–600. Bibcode:2014FuEco..28..589C. doi:10.1111/1365-2435.12202. https://doi.org/10.1111%2F1365-2435.12202 ↩

  219. Hargrove, J.L. (2005). "Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds". Nutrition Journal. 4: 36. doi:10.1186/1475-2891-4-36. PMC 1325055. PMID 16351726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325055 ↩

  220. Hargrove, J.L. (2005). "Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds". Nutrition Journal. 4: 36. doi:10.1186/1475-2891-4-36. PMC 1325055. PMID 16351726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325055 ↩

  221. Skutch, Alexander F. & Singer, Arthur B. (1973). The Life of the Hummingbird. New York: Crown Publishers. ISBN 978-0-517-50572-4. 978-0-517-50572-4 ↩

  222. Hargrove, J.L. (2005). "Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds". Nutrition Journal. 4: 36. doi:10.1186/1475-2891-4-36. PMC 1325055. PMID 16351726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325055 ↩

  223. Hargrove, J.L. (2005). "Adipose energy stores, physical work, and the metabolic syndrome: Lessons from hummingbirds". Nutrition Journal. 4: 36. doi:10.1186/1475-2891-4-36. PMC 1325055. PMID 16351726. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1325055 ↩

  224. Lasiewski, Robert C. (1964). "Body temperatures, heart and breathing rate, and evaporative water loss in hummingbirds". Physiological Zoology. 37 (2): 212–223. doi:10.1086/physzool.37.2.30152332. S2CID 87037075. /wiki/Doi_(identifier) ↩

  225. Powers, Donald R.; Langland, Kathleen M.; Wethington, Susan M.; Powers, Sean D.; Graham, Catherine H.; Tobalske, Bret W. (2017). "Hovering in the heat: effects of environmental temperature on heat regulation in foraging hummingbirds". Royal Society Open Science. 4 (12): 171056. doi:10.1098/rsos.171056. ISSN 2054-5703. PMC 5750011. PMID 29308244. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5750011 ↩

  226. Evangelista, Dennis; Fernández, María José; Berns, Madalyn S.; Hoover, Aaron; Dudley, Robert (2010). "Hovering energetics and thermal balance in Anna's hummingbirds (Calypte anna)". Physiological and Biochemical Zoology. 83 (3): 406–413. doi:10.1086/651460. ISSN 1522-2152. PMID 20350142. S2CID 26974159. https://www.researchgate.net/publication/42638033 ↩

  227. Soniak, Matt (2 February 2016). "Infrared video shows how hummingbirds shed heat through their eyes and feet". Mental Floss. Retrieved 14 January 2020. https://www.mentalfloss.com/article/74571/infrared-video-shows-how-hummingbirds-shed-heat-through-their-eyes-and-feet ↩

  228. Powers, Donald R.; Langland, Kathleen M.; Wethington, Susan M.; Powers, Sean D.; Graham, Catherine H.; Tobalske, Bret W. (2017). "Hovering in the heat: effects of environmental temperature on heat regulation in foraging hummingbirds". Royal Society Open Science. 4 (12): 171056. doi:10.1098/rsos.171056. ISSN 2054-5703. PMC 5750011. PMID 29308244. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5750011 ↩

  229. Udvardy, Miklos D.F. (1983). "The role of the feet in behavioral thermoregulation of hummingbirds" (PDF). Condor. 85 (3): 281–285. doi:10.2307/1367060. JSTOR 1367060. https://sora.unm.edu/sites/default/files/journals/condor/v085n03/p0281-p0285.pdf ↩

  230. Powers, Donald R.; Langland, Kathleen M.; Wethington, Susan M.; Powers, Sean D.; Graham, Catherine H.; Tobalske, Bret W. (2017). "Hovering in the heat: effects of environmental temperature on heat regulation in foraging hummingbirds". Royal Society Open Science. 4 (12): 171056. doi:10.1098/rsos.171056. ISSN 2054-5703. PMC 5750011. PMID 29308244. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5750011 ↩

  231. Powers, Donald R.; Langland, Kathleen M.; Wethington, Susan M.; Powers, Sean D.; Graham, Catherine H.; Tobalske, Bret W. (2017). "Hovering in the heat: effects of environmental temperature on heat regulation in foraging hummingbirds". Royal Society Open Science. 4 (12): 171056. doi:10.1098/rsos.171056. ISSN 2054-5703. PMC 5750011. PMID 29308244. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5750011 ↩

  232. Udvardy, Miklos D.F. (1983). "The role of the feet in behavioral thermoregulation of hummingbirds" (PDF). Condor. 85 (3): 281–285. doi:10.2307/1367060. JSTOR 1367060. https://sora.unm.edu/sites/default/files/journals/condor/v085n03/p0281-p0285.pdf ↩

  233. Suarez, R.K.; Gass, C.L. (2002). "Hummingbirds foraging and the relation between bioenergetics and behavior". Comparative Biochemistry and Physiology. Part A. 133 (2): 335–343. doi:10.1016/S1095-6433(02)00165-4. PMID 12208304."How do hummingbirds thrive in the Andes?". The Guardian. 13 December 2013. Retrieved 15 August 2022. /wiki/Doi_(identifier) ↩

  234. Bakken, B.H.; McWhorter, T.J.; Tsahar, E.; Martinez del Rio, C. (2004). "Hummingbirds arrest their kidneys at night: diel variation in glomerular filtration rate in Selasphorus platycercus". The Journal of Experimental Biology. 207 (25): 4383–391. Bibcode:2004JExpB.207.4383B. doi:10.1242/jeb.01238. hdl:2440/55466. PMID 15557024. https://doi.org/10.1242%2Fjeb.01238 ↩

  235. Bakken, B.H.; McWhorter, T.J.; Tsahar, E.; Martinez del Rio, C. (2004). "Hummingbirds arrest their kidneys at night: diel variation in glomerular filtration rate in Selasphorus platycercus". The Journal of Experimental Biology. 207 (25): 4383–391. Bibcode:2004JExpB.207.4383B. doi:10.1242/jeb.01238. hdl:2440/55466. PMID 15557024. https://doi.org/10.1242%2Fjeb.01238 ↩

  236. Bakken, B.H.; Sabat, P. (2006). "Gastrointestinal and renal responses to water intake in the green-backed firecrown (Sephanoides sephanoides), a South American hummingbird". AJP: Regulatory, Integrative and Comparative Physiology. 291 (3): R830–836. doi:10.1152/ajpregu.00137.2006. hdl:10533/177203. PMID 16614056. S2CID 2391784. http://americanae.aecid.es/americanae/es/registros/registro.do?tipoRegistro=MTD&idBib=3228740 ↩

  237. Bakken, B.H.; McWhorter, T.J.; Tsahar, E.; Martinez del Rio, C. (2004). "Hummingbirds arrest their kidneys at night: diel variation in glomerular filtration rate in Selasphorus platycercus". The Journal of Experimental Biology. 207 (25): 4383–391. Bibcode:2004JExpB.207.4383B. doi:10.1242/jeb.01238. hdl:2440/55466. PMID 15557024. https://doi.org/10.1242%2Fjeb.01238 ↩

  238. Bakken, B.H.; Sabat, P. (2006). "Gastrointestinal and renal responses to water intake in the green-backed firecrown (Sephanoides sephanoides), a South American hummingbird". AJP: Regulatory, Integrative and Comparative Physiology. 291 (3): R830–836. doi:10.1152/ajpregu.00137.2006. hdl:10533/177203. PMID 16614056. S2CID 2391784. http://americanae.aecid.es/americanae/es/registros/registro.do?tipoRegistro=MTD&idBib=3228740 ↩

  239. Lotz, Chris N.; Martínez Del Rio, Carlos (2004). "The ability of rufous hummingbirds Selasphorus rufus to dilute and concentrate urine". Journal of Avian Biology. 35: 54–62. doi:10.1111/j.0908-8857.2004.03083.x.Gayman, Deann (2 December 2013). "New study reveals how hummingbirds evolved to fly at high altitude". Department of Communication and Marketing, University of Nebraska-Lincoln. Retrieved 15 August 2022. /wiki/Doi_(identifier) ↩

  240. Bakken, B.H.; Sabat, P. (2006). "Gastrointestinal and renal responses to water intake in the green-backed firecrown (Sephanoides sephanoides), a South American hummingbird". AJP: Regulatory, Integrative and Comparative Physiology. 291 (3): R830–836. doi:10.1152/ajpregu.00137.2006. hdl:10533/177203. PMID 16614056. S2CID 2391784. http://americanae.aecid.es/americanae/es/registros/registro.do?tipoRegistro=MTD&idBib=3228740 ↩

  241. Beuchat, C.A.; Preest, M.R.; Braun, E.J. (1999). "Glomerular and medullary architecture in the kidney of Anna's Hummingbird". Journal of Morphology. 240 (2): 95–100. doi:10.1002/(sici)1097-4687(199905)240:2<95::aid-jmor1>3.0.co;2-u. PMID 29847878. S2CID 44156688. /wiki/Doi_(identifier) ↩

  242. Projecto-Garcia, Joana; Natarajan, Chandrasekhar; Moriyama, Hideaki; et al. (2 December 2013). "Repeated elevational transitions in hemoglobin function during the evolution of Andean hummingbirds". Proceedings of the National Academy of Sciences of the United States of America. 110 (51): 20669–20674. Bibcode:2013PNAS..11020669P. doi:10.1073/pnas.1315456110. ISSN 0027-8424. PMC 3870697. PMID 24297909. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3870697 ↩

  243. Suarez, R.K.; Gass, C.L. (2002). "Hummingbirds foraging and the relation between bioenergetics and behavior". Comparative Biochemistry and Physiology. Part A. 133 (2): 335–343. doi:10.1016/S1095-6433(02)00165-4. PMID 12208304."How do hummingbirds thrive in the Andes?". The Guardian. 13 December 2013. Retrieved 15 August 2022. /wiki/Doi_(identifier) ↩

  244. Lim, Marisa C.W.; Witt, Christopher C.; Graham, Catherine H.; Dávalos, Liliana M. (22 May 2019). "Parallel molecular evolution in pathways, genes, and sites in high-elevation hummingbirds revealed by comparative transcriptomics". Genome Biology and Evolution. 11 (6): 1573–1585. doi:10.1093/gbe/evz101. ISSN 1759-6653. PMC 6553505. PMID 31114863. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6553505 ↩

  245. Projecto-Garcia, Joana; Natarajan, Chandrasekhar; Moriyama, Hideaki; et al. (2 December 2013). "Repeated elevational transitions in hemoglobin function during the evolution of Andean hummingbirds". Proceedings of the National Academy of Sciences of the United States of America. 110 (51): 20669–20674. Bibcode:2013PNAS..11020669P. doi:10.1073/pnas.1315456110. ISSN 0027-8424. PMC 3870697. PMID 24297909. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3870697 ↩

  246. Suarez, R.K.; Gass, C.L. (2002). "Hummingbirds foraging and the relation between bioenergetics and behavior". Comparative Biochemistry and Physiology. Part A. 133 (2): 335–343. doi:10.1016/S1095-6433(02)00165-4. PMID 12208304."How do hummingbirds thrive in the Andes?". The Guardian. 13 December 2013. Retrieved 15 August 2022. /wiki/Doi_(identifier) ↩

  247. Lotz, Chris N.; Martínez Del Rio, Carlos (2004). "The ability of rufous hummingbirds Selasphorus rufus to dilute and concentrate urine". Journal of Avian Biology. 35: 54–62. doi:10.1111/j.0908-8857.2004.03083.x.Gayman, Deann (2 December 2013). "New study reveals how hummingbirds evolved to fly at high altitude". Department of Communication and Marketing, University of Nebraska-Lincoln. Retrieved 15 August 2022. /wiki/Doi_(identifier) ↩

  248. Greig, Emma I.; Wood, Eric M.; Bonter, David N. (5 April 2017). "Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding". Proceedings of the Royal Society B: Biological Sciences. 284 (1852): 20170256. doi:10.1098/rspb.2017.0256. ISSN 0962-8452. PMC 5394677. PMID 28381617. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394677 ↩

  249. Battey, C. J. (2019). "Ecological release of the Anna's hummingbird during a northern range expansion". The American Naturalist. 194 (3): 306–315. Bibcode:2019ANat..194..306B. doi:10.1086/704249. ISSN 0003-0147. PMID 31553208. S2CID 164398193. https://doi.org/10.1086%2F704249 ↩

  250. Greig, Emma I.; Wood, Eric M.; Bonter, David N. (5 April 2017). "Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding". Proceedings of the Royal Society B: Biological Sciences. 284 (1852): 20170256. doi:10.1098/rspb.2017.0256. ISSN 0962-8452. PMC 5394677. PMID 28381617. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394677 ↩

  251. Battey, C. J. (2019). "Ecological release of the Anna's hummingbird during a northern range expansion". The American Naturalist. 194 (3): 306–315. Bibcode:2019ANat..194..306B. doi:10.1086/704249. ISSN 0003-0147. PMID 31553208. S2CID 164398193. https://doi.org/10.1086%2F704249 ↩

  252. Beuchat, C.A.; Chaplin, S.B.; Morton, M.L. (1979). "Ambient temperature and the daily energetics of two species of hummingbirds, Calypte anna and Selasphorus rufus". Physiological Zoology. 52 (3): 280–295. doi:10.1086/physzool.52.3.30155751. S2CID 87185364. /wiki/Doi_(identifier) ↩

  253. Powers, D. R. (1991). "Diurnal variation in mass, metabolic rate, and respiratory quotient in Anna's and Costa's hummingbirds" (PDF). Physiological Zoology. 64 (3): 850–870. doi:10.1086/physzool.64.3.30158211. JSTOR 30158211. S2CID 55730100. http://www.dpowerslab.com/wp-content/uploads/2011/09/PZ1991.pdf ↩

  254. Shankar, Anusha; Schroeder, Rebecca J.; Wethington, Susan M.; Graham, Catherine H.; Powers, Donald R. (May 2020). "Hummingbird torpor in context: duration, more than temperature, is the key to nighttime energy savings". Journal of Avian Biology. 51 (5): jav.02305. doi:10.1111/jav.02305. ISSN 0908-8857. S2CID 216458501. https://onlinelibrary.wiley.com/doi/10.1111/jav.02305 ↩

  255. Battey, C. J. (2019). "Ecological release of the Anna's hummingbird during a northern range expansion". The American Naturalist. 194 (3): 306–315. Bibcode:2019ANat..194..306B. doi:10.1086/704249. ISSN 0003-0147. PMID 31553208. S2CID 164398193. https://doi.org/10.1086%2F704249 ↩

  256. Clark CJ, Russell SM (2012). "Anna's hummingbird (Calypte anna)". The Birds of North America Online. The Birds of North America, Cornell University Laboratory of Ornithology. doi:10.2173/bna.226. https://birdsoftheworld.org/bow/species/annhum/1.0/introduction ↩

  257. Battey, C. J. (2019). "Ecological release of the Anna's hummingbird during a northern range expansion". The American Naturalist. 194 (3): 306–315. Bibcode:2019ANat..194..306B. doi:10.1086/704249. ISSN 0003-0147. PMID 31553208. S2CID 164398193. https://doi.org/10.1086%2F704249 ↩

  258. Greig, Emma I.; Wood, Eric M.; Bonter, David N. (5 April 2017). "Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding". Proceedings of the Royal Society B: Biological Sciences. 284 (1852): 20170256. doi:10.1098/rspb.2017.0256. ISSN 0962-8452. PMC 5394677. PMID 28381617. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394677 ↩

  259. Battey, C. J. (2019). "Ecological release of the Anna's hummingbird during a northern range expansion". The American Naturalist. 194 (3): 306–315. Bibcode:2019ANat..194..306B. doi:10.1086/704249. ISSN 0003-0147. PMID 31553208. S2CID 164398193. https://doi.org/10.1086%2F704249 ↩

  260. Greig, Emma I.; Wood, Eric M.; Bonter, David N. (5 April 2017). "Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding". Proceedings of the Royal Society B: Biological Sciences. 284 (1852): 20170256. doi:10.1098/rspb.2017.0256. ISSN 0962-8452. PMC 5394677. PMID 28381617. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394677 ↩

  261. "Official City Bird: Anna's Hummingbird". City of Vancouver. 2019. Retrieved 6 November 2019. https://vancouver.ca/parks-recreation-culture/official-city-bird.aspx ↩

  262. Green, Gregory A. (2 October 2018). "Anna's Hummingbird: Our winter hummingbird". BirdWatching. Retrieved 6 November 2019. https://www.birdwatchingdaily.com/news/species-profiles/annas-hummingbird-our-winter-hummingbird/# ↩

  263. Bakken, B.H.; McWhorter, T.J.; Tsahar, E.; Martinez del Rio, C. (2004). "Hummingbirds arrest their kidneys at night: diel variation in glomerular filtration rate in Selasphorus platycercus". The Journal of Experimental Biology. 207 (25): 4383–391. Bibcode:2004JExpB.207.4383B. doi:10.1242/jeb.01238. hdl:2440/55466. PMID 15557024. https://doi.org/10.1242%2Fjeb.01238 ↩

  264. Hainsworth, F.R.; Wolf, L.L. (1970). "Regulation of oxygen consumption and body temperature during torpor in a hummingbird, Eulampis jugularis". Science. 168 (3929): 368–369. Bibcode:1970Sci...168..368R. doi:10.1126/science.168.3929.368. PMID 5435893. S2CID 30793291. /wiki/Bibcode_(identifier) ↩

  265. Hiebert, S.M. (1992). "Time-dependent thresholds for torpor initiation in the rufous hummingbird (Selasphorus rufus)". Journal of Comparative Physiology B. 162 (3): 249–255. doi:10.1007/bf00357531. PMID 1613163. S2CID 24688360. /wiki/Doi_(identifier) ↩

  266. Wolf, Blair O.; McKechnie, Andrew E.; Schmitt, C. Jonathan; Czenze, Zenon J.; Johnson, Andrew B.; Witt, Christopher C. (2020). "Extreme and variable torpor among high-elevation Andean hummingbird species". Biology Letters. 16 (9): 20200428. doi:10.1098/rsbl.2020.0428. ISSN 1744-9561. PMC 7532710. PMID 32898456. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7532710 ↩

  267. Greenwood, Veronique (8 September 2020). "These hummingbirds take extreme naps. Some may even hibernate". The New York Times. ISSN 0362-4331. Retrieved 9 September 2020. https://www.nytimes.com/2020/09/08/science/hummingbirds-torpor-hibernation.html ↩

  268. Wolf, Blair O.; McKechnie, Andrew E.; Schmitt, C. Jonathan; Czenze, Zenon J.; Johnson, Andrew B.; Witt, Christopher C. (2020). "Extreme and variable torpor among high-elevation Andean hummingbird species". Biology Letters. 16 (9): 20200428. doi:10.1098/rsbl.2020.0428. ISSN 1744-9561. PMC 7532710. PMID 32898456. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7532710 ↩

  269. Wolf, Blair O.; McKechnie, Andrew E.; Schmitt, C. Jonathan; Czenze, Zenon J.; Johnson, Andrew B.; Witt, Christopher C. (2020). "Extreme and variable torpor among high-elevation Andean hummingbird species". Biology Letters. 16 (9): 20200428. doi:10.1098/rsbl.2020.0428. ISSN 1744-9561. PMC 7532710. PMID 32898456. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7532710 ↩

  270. Bakken, B.H.; McWhorter, T.J.; Tsahar, E.; Martinez del Rio, C. (2004). "Hummingbirds arrest their kidneys at night: diel variation in glomerular filtration rate in Selasphorus platycercus". The Journal of Experimental Biology. 207 (25): 4383–391. Bibcode:2004JExpB.207.4383B. doi:10.1242/jeb.01238. hdl:2440/55466. PMID 15557024. https://doi.org/10.1242%2Fjeb.01238 ↩

  271. Hiebert, S.M.; Salvante, K.G.; Ramenofsky, M.; Wingfield, J.C. (2000). "Corticosterone and nocturnal torpor in the rufous hummingbird (Selasphorus rufus)". General and Comparative Endocrinology. 120 (2): 220–234. doi:10.1006/gcen.2000.7555. PMID 11078633. /wiki/Doi_(identifier) ↩

  272. Powers, D.R.; Brown, A.R.; Van Hook, J.A. (2003). "Influence of normal daytime fat deposition on laboratory measurements of torpor use in territorial versus nonterritorial hummingbirds". Physiological and Biochemical Zoology. 76 (3): 389–397. doi:10.1086/374286. PMID 12905125. S2CID 6475160. https://digitalcommons.georgefox.edu/cgi/viewcontent.cgi?article=1025&context=bio_fac ↩

  273. Shankar, Anusha; Schroeder, Rebecca J.; Wethington, Susan M.; Graham, Catherine H.; Powers, Donald R. (May 2020). "Hummingbird torpor in context: duration, more than temperature, is the key to nighttime energy savings". Journal of Avian Biology. 51 (5): jav.02305. doi:10.1111/jav.02305. ISSN 0908-8857. S2CID 216458501. https://onlinelibrary.wiley.com/doi/10.1111/jav.02305 ↩

  274. Shankar, Anusha; Schroeder, Rebecca J.; Wethington, Susan M.; Graham, Catherine H.; Powers, Donald R. (May 2020). "Hummingbird torpor in context: duration, more than temperature, is the key to nighttime energy savings". Journal of Avian Biology. 51 (5): jav.02305. doi:10.1111/jav.02305. ISSN 0908-8857. S2CID 216458501. https://onlinelibrary.wiley.com/doi/10.1111/jav.02305 ↩

  275. "The hummingbird project of British Columbia". Rocky Point Bird Observatory, Vancouver Island, British Columbia. 2010. Archived from the original on 2 February 2017. Retrieved 25 June 2016. https://web.archive.org/web/20170202002338/http://rpbo.org/hummingbirds.php ↩

  276. "The hummingbird project of British Columbia". Rocky Point Bird Observatory, Vancouver Island, British Columbia. 2010. Archived from the original on 2 February 2017. Retrieved 25 June 2016. https://web.archive.org/web/20170202002338/http://rpbo.org/hummingbirds.php ↩

  277. Churchfield, Sara (1990). The natural history of shrews. Cornell University Press. pp. 35–37. ISBN 978-0-8014-2595-0. 978-0-8014-2595-0 ↩

  278. "Longevity Records Of North American Birds". United States Geological Survey. Retrieved 26 January 2021. https://www.pwrc.usgs.gov/BBL/longevity/Longevity_main.cfm ↩

  279. "Longevity Records AOU Numbers 3930–4920". Patuxent Wildlife Research Center, Bird Banding Laboratory. 31 August 2009. Retrieved 27 September 2009. https://www.pwrc.usgs.gov/BBL/homepage/long3930.cfm ↩

  280. Fisher, R. Jr. (1994). "Praying mantis catches and eats hummingbird". Birding. 26: 376. ↩

  281. Lorenz, S. (2007). "Carolina mantid (Stagmomantis carolina) captures and feeds on a broad-tailed hummingbird (Selasphorus platycercus)". Bulletin of the Texas Ornithological Society. 40: 37–38. ↩

  282. Nyffeler, Martin; Maxwell, Michael R.; Remsen, J.V. (2017). "Bird predation by praying mantises: A global perspective". The Wilson Journal of Ornithology. 129 (2): 331–344. doi:10.1676/16-100.1. ISSN 1559-4491. S2CID 90832425. https://bioone.org/journals/the-wilson-journal-of-ornithology/volume-129/issue-2/16-100.1/Bird-Predation-By-Praying-Mantises-A-Global-Perspective/10.1676/16-100.1.full ↩

  283. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  284. Stiteler, Sharon (29 October 2015). "Which animals prey on hummingbirds?". National Audubon Society. Retrieved 4 November 2021. https://www.audubon.org/news/which-animals-prey-hummingbirds ↩

  285. Oniki-Willis, Yoshika; Willis, Edwin O; Lopes, Leonardo E; Rozsa, Lajos (2023). "Museum-based research on the lice (Insecta: Phthiraptera) infestations of hummingbirds (Aves: Trochilidae) – prevalence, genus richness, and parasite associations". Diversity. 15 (1): 54. Bibcode:2023Diver..15...54O. doi:10.3390/d15010054. https://doi.org/10.3390%2Fd15010054 ↩

  286. Sychra, Oldřich; et al. (2024). "Multivariate study of lice (Insecta: Psocodea: Phthiraptera) assemblages hosted by hummingbirds (Aves: Trochilidae)". Parasitology. 151 (2): 191–199. doi:10.1017/S0031182023001294. PMC 10941040. PMID 38116659. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10941040 ↩

  287. Oniki, Y; Willis, E.O. (2000). "Nesting behavior of the swallow-tailed hummingbird, Eupetomena macroura (Trochilidae, Aves)". Brazilian Journal of Biology. 60 (4): 655–662. doi:10.1590/s0034-71082000000400016. hdl:11449/28969. PMID 11241965. https://doi.org/10.1590%2Fs0034-71082000000400016 ↩

  288. "Hummingbird nesting". Public Broadcasting System – Nature; from Learner.org, Journey North. 2016. Archived from the original (video) on 2 February 2017. Retrieved 12 May 2016. https://web.archive.org/web/20170202001143/http://www.learner.org/jnorth/humm/spring2016/c051316_nest.html ↩

  289. Oniki, Y; Willis, E.O. (2000). "Nesting behavior of the swallow-tailed hummingbird, Eupetomena macroura (Trochilidae, Aves)". Brazilian Journal of Biology. 60 (4): 655–662. doi:10.1590/s0034-71082000000400016. hdl:11449/28969. PMID 11241965. https://doi.org/10.1590%2Fs0034-71082000000400016 ↩

  290. "Hummingbird nesting". Public Broadcasting System – Nature; from Learner.org, Journey North. 2016. Archived from the original (video) on 2 February 2017. Retrieved 12 May 2016. https://web.archive.org/web/20170202001143/http://www.learner.org/jnorth/humm/spring2016/c051316_nest.html ↩

  291. "Hummingbird Q&A: Nest and eggs". Operation Rubythroat: The Hummingbird Project, Hilton Pond Center for Piedmont Natural History. 2014. Retrieved 21 June 2014. http://www.rubythroat.org/questionsnesteggs01.html ↩

  292. "Ruby-throated hummingbird". All About Birds, Cornell University Laboratory of Ornithology. 2023. Retrieved 23 April 2023. https://www.allaboutbirds.org/guide/Ruby-throated_Hummingbird/ ↩

  293. "Hummingbird nesting". Public Broadcasting System – Nature; from Learner.org, Journey North. 2016. Archived from the original (video) on 2 February 2017. Retrieved 12 May 2016. https://web.archive.org/web/20170202001143/http://www.learner.org/jnorth/humm/spring2016/c051316_nest.html ↩

  294. "Hummingbird nesting". Public Broadcasting System – Nature; from Learner.org, Journey North. 2016. Archived from the original (video) on 2 February 2017. Retrieved 12 May 2016. https://web.archive.org/web/20170202001143/http://www.learner.org/jnorth/humm/spring2016/c051316_nest.html ↩

  295. "Ruby-throated hummingbird". All About Birds, Cornell University Laboratory of Ornithology. 2023. Retrieved 23 April 2023. https://www.allaboutbirds.org/guide/Ruby-throated_Hummingbird/ ↩

  296. Oniki, Y; Willis, E.O. (2000). "Nesting behavior of the swallow-tailed hummingbird, Eupetomena macroura (Trochilidae, Aves)". Brazilian Journal of Biology. 60 (4): 655–662. doi:10.1590/s0034-71082000000400016. hdl:11449/28969. PMID 11241965. https://doi.org/10.1590%2Fs0034-71082000000400016 ↩

  297. Oniki, Y; Willis, E.O. (2000). "Nesting behavior of the swallow-tailed hummingbird, Eupetomena macroura (Trochilidae, Aves)". Brazilian Journal of Biology. 60 (4): 655–662. doi:10.1590/s0034-71082000000400016. hdl:11449/28969. PMID 11241965. https://doi.org/10.1590%2Fs0034-71082000000400016 ↩

  298. Mohrman, Eric (22 November 2019). "How do hummingbirds mate?". Sciencing, Leaf Group Media. Retrieved 8 February 2020. https://sciencing.com/hummingbirds-mate-4566850.html ↩

  299. Warrick, Douglas R.; Tobalske, Bret W.; Powers, Donald R. (2005). "Aerodynamics of the hovering hummingbird". Nature. 435 (7045): 1094–097. Bibcode:2005Natur.435.1094W. doi:10.1038/nature03647. PMID 15973407. S2CID 4427424. https://digitalcommons.georgefox.edu/cgi/viewcontent.cgi?article=1033&context=bio_fac ↩

  300. Sapir, N.; Dudley, R. (2012). "Backward flight in hummingbirds employs unique kinematic adjustments and entails low metabolic cost". Journal of Experimental Biology. 215 (20): 3603–611. Bibcode:2012JExpB.215.3603S. doi:10.1242/jeb.073114. PMID 23014570. https://doi.org/10.1242%2Fjeb.073114 ↩

  301. Tobalske, Bret W.; Warrick, Douglas R.; Clark, Christopher J.; Powers, Donald R.; Hedrick, Tyson L.; Hyder, Gabriel A.; Biewener, Andrew A. (2007). "Three-dimensional kinematics of hummingbird flight". J Exp Biol. 210 (13): 2368–382. Bibcode:2007JExpB.210.2368T. doi:10.1242/jeb.005686. PMID 17575042. https://doi.org/10.1242%2Fjeb.005686 ↩

  302. Warrick, Douglas R.; Tobalske, Bret W.; Powers, Donald R. (2005). "Aerodynamics of the hovering hummingbird". Nature. 435 (7045): 1094–097. Bibcode:2005Natur.435.1094W. doi:10.1038/nature03647. PMID 15973407. S2CID 4427424. https://digitalcommons.georgefox.edu/cgi/viewcontent.cgi?article=1033&context=bio_fac ↩

  303. Warrick, Douglas R.; Tobalske, Bret W.; Powers, Donald R. (2005). "Aerodynamics of the hovering hummingbird". Nature. 435 (7045): 1094–097. Bibcode:2005Natur.435.1094W. doi:10.1038/nature03647. PMID 15973407. S2CID 4427424. https://digitalcommons.georgefox.edu/cgi/viewcontent.cgi?article=1033&context=bio_fac ↩

  304. Tobalske, B.W.; Biewener, A.A.; Warrick, D.R.; Hedrick, T.L.; Powers, D.R. (2010). "Effects of flight speed upon muscle activity in hummingbirds". Journal of Experimental Biology. 213 (14): 2515–523. Bibcode:2010JExpB.213.2515T. doi:10.1242/jeb.043844. PMID 20581281. https://doi.org/10.1242%2Fjeb.043844 ↩

  305. Videler, J.J. (2005). Avian Flight. Oxford University Press, Ornithology Series. p. 34. ISBN 978-0-19-856603-8. 978-0-19-856603-8 ↩

  306. Fernández, M.J.; Dudley, R.; Bozinovic, F. (2011). "Comparative energetics of the giant hummingbird (Patagona gigas)". Physiological and Biochemical Zoology. 84 (3): 333–340. doi:10.1086/660084. PMID 21527824. S2CID 31616893. /wiki/Doi_(identifier) ↩

  307. Gill, V. (30 July 2014). "Hummingbirds edge out helicopters in hover contest". BBC News. Retrieved 1 September 2014. https://www.bbc.com/news/28563737 ↩

  308. Feinsinger, Peter; Colwell, Robert K.; Terborgh, John; Chaplin, Susan Budd (1979). "Elevation and the Morphology, Flight Energetics, and Foraging Ecology of Tropical Hummingbirds". The American Naturalist. 113 (4): 481–497. Bibcode:1979ANat..113..481F. doi:10.1086/283408. ISSN 0003-0147. S2CID 85317341. /wiki/Bibcode_(identifier) ↩

  309. Morelle, R. (8 November 2011). "Hummingbirds shake their heads to deal with rain". BBC News. Retrieved 22 March 2014. /wiki/Rebecca_Morelle ↩

  310. St. Fleur, N. (20 July 2012). "Hummingbird rain trick: New study shows tiny birds alter posture in storms" (video). Huffington Post. Retrieved 22 March 2014. http://www.huffingtonpost.com/2012/07/19/hummingbird-rain-video_n_1685752.html ↩

  311. Wilcox, Sean; Clark, Christopher (2022). "Sexual selection for flight performance in hummingbirds". Behavioral Ecology. 33 (6): 1093–1106. doi:10.1093/beheco/arac075. https://academic.oup.com/beheco/article/33/6/1093/6686581 ↩

  312. Wilcox, Sean; Clark, Christopher (2022). "Sexual selection for flight performance in hummingbirds". Behavioral Ecology. 33 (6): 1093–1106. doi:10.1093/beheco/arac075. https://academic.oup.com/beheco/article/33/6/1093/6686581 ↩

  313. Clark, C.J. (2011). "Wing, tail, and vocal contributions to the complex acoustic signals of courting Calliope hummingbirds". Current Zool. 57 (2): 187–196. doi:10.1093/czoolo/57.2.187. https://doi.org/10.1093%2Fczoolo%2F57.2.187 ↩

  314. Ravi, Sridhar; Crall, James D.; McNeilly, Lucas; Gagliardi, Susan F.; Biewener, Andrew A.; Combes, Stacey A. (2015). "Hummingbird flight stability and control in freestream turbulent winds". J Exp Biol. 218 (Pt 9): 1444–452. doi:10.1242/jeb.114553. PMID 25767146. https://doi.org/10.1242%2Fjeb.114553 ↩

  315. Ravi, Sridhar; Crall, James D.; McNeilly, Lucas; Gagliardi, Susan F.; Biewener, Andrew A.; Combes, Stacey A. (2015). "Hummingbird flight stability and control in freestream turbulent winds". J Exp Biol. 218 (Pt 9): 1444–452. doi:10.1242/jeb.114553. PMID 25767146. https://doi.org/10.1242%2Fjeb.114553 ↩

  316. Ravi, Sridhar; Crall, James D.; McNeilly, Lucas; Gagliardi, Susan F.; Biewener, Andrew A.; Combes, Stacey A. (2015). "Hummingbird flight stability and control in freestream turbulent winds". J Exp Biol. 218 (Pt 9): 1444–452. doi:10.1242/jeb.114553. PMID 25767146. https://doi.org/10.1242%2Fjeb.114553 ↩

  317. Goller, B.; Altshuler, D.L. (2014). "Hummingbirds control hovering flight by stabilizing visual motion". Proceedings of the National Academy of Sciences. 111 (51): 18375–380. Bibcode:2014PNAS..11118375G. doi:10.1073/pnas.1415975111. PMC 4280641. PMID 25489117. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4280641 ↩

  318. Goller, B.; Altshuler, D.L. (2014). "Hummingbirds control hovering flight by stabilizing visual motion". Proceedings of the National Academy of Sciences. 111 (51): 18375–380. Bibcode:2014PNAS..11118375G. doi:10.1073/pnas.1415975111. PMC 4280641. PMID 25489117. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4280641 ↩

  319. Clark, C.J. (2009). "Courtship dives of Anna's hummingbird offer insights into flight performance limits". Proceedings of the Royal Society B: Biological Sciences. 276 (1670): 3047–052. doi:10.1098/rspb.2009.0508. PMC 2817121. PMID 19515669. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2817121 ↩

  320. Clark, C.J. (2009). "Courtship dives of Anna's hummingbird offer insights into flight performance limits". Proceedings of the Royal Society B: Biological Sciences. 276 (1670): 3047–052. doi:10.1098/rspb.2009.0508. PMC 2817121. PMID 19515669. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2817121 ↩

  321. Clark, C.J. (2009). "Courtship dives of Anna's hummingbird offer insights into flight performance limits". Proceedings of the Royal Society B: Biological Sciences. 276 (1670): 3047–052. doi:10.1098/rspb.2009.0508. PMC 2817121. PMID 19515669. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2817121 ↩

  322. By comparison to humans, this is a G-force acceleration well beyond the threshold of causing near loss of consciousness (occurring at about +5 Gz) in fighter pilots during operation of a fixed-wing aircraft in a high-speed banked turn.[160][161] /wiki/Consciousness ↩

  323. Clark, C. J.; Feo, T.J. (2008). "The Anna's hummingbird chirps with its tail: A new mechanism of sonation in birds". Proceedings of the Royal Society B: Biological Sciences. 275 (1637): 955–962. doi:10.1098/rspb.2007.1619. PMC 2599939. PMID 18230592. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2599939 ↩

  324. Clark, C.J. (2014). "Harmonic hopping, and both punctuated and gradual evolution of acoustic characters in Selasphorus hummingbird tail-feathers". PLOS ONE. 9 (4): e93829. Bibcode:2014PLoSO...993829C. doi:10.1371/journal.pone.0093829. PMC 3983109. PMID 24722049. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983109 ↩

  325. Clark, C. J.; Feo, T.J. (2008). "The Anna's hummingbird chirps with its tail: A new mechanism of sonation in birds". Proceedings of the Royal Society B: Biological Sciences. 275 (1637): 955–962. doi:10.1098/rspb.2007.1619. PMC 2599939. PMID 18230592. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2599939 ↩

  326. Clark, C. J.; Feo, T. J. (2010). "Why do Calypte hummingbirds "sing" with both their tail and their syrinx? An apparent example of sexual sensory bias". The American Naturalist. 175 (1): 27–37. Bibcode:2010ANat..175...27C. doi:10.1086/648560. PMID 19916787. S2CID 29680714. /wiki/Bibcode_(identifier) ↩

  327. Clark, C. J.; Feo, T.J. (2008). "The Anna's hummingbird chirps with its tail: A new mechanism of sonation in birds". Proceedings of the Royal Society B: Biological Sciences. 275 (1637): 955–962. doi:10.1098/rspb.2007.1619. PMC 2599939. PMID 18230592. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2599939 ↩

  328. Clark, C.J.; Elias, D.O.; Prum, R.O. (2013). "Hummingbird feather sounds are produced by aeroelastic flutter, not vortex-induced vibration". Journal of Experimental Biology. 216 (18): 3395–403. doi:10.1242/jeb.080317. PMID 23737562. https://doi.org/10.1242%2Fjeb.080317 ↩

  329. Clark, C.J. (2011). "Wing, tail, and vocal contributions to the complex acoustic signals of courting Calliope hummingbirds" (PDF). Current Zoology. 57 (2): 187–196. doi:10.1093/czoolo/57.2.187. Archived from the original (PDF) on 16 July 2015. Retrieved 31 May 2015. https://web.archive.org/web/20150716160821/http://www.actazool.org/temp/%7BACDC40CC-89E0-41E6-A4B2-7C7FB6734F1E%7D.pdf ↩

  330. Kovacevic, M. (30 January 2008). "Hummingbird sings with its tail feathers". Cosmos Magazine. Archived from the original on 3 May 2012. Retrieved 13 July 2013. https://web.archive.org/web/20120503042604/http://www.cosmosmagazine.com/news/1829/hummingbird-sings-with-its-tail-feathers ↩

  331. Clark, C.J. (2014). "Harmonic hopping, and both punctuated and gradual evolution of acoustic characters in Selasphorus hummingbird tail-feathers". PLOS ONE. 9 (4): e93829. Bibcode:2014PLoSO...993829C. doi:10.1371/journal.pone.0093829. PMC 3983109. PMID 24722049. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983109 ↩

  332. Miller, Sarah J.; Inouye, David W. (1983). "Roles of the Wing Whistle in the Territorial Behaviour of Male Broad-tailed Hummingbirds (Selasphorus platycercus)". Animal Behaviour. 31 (3): 689–700. doi:10.1016/S0003-3472(83)80224-3. S2CID 53160649. Retrieved 13 July 2014 – via hummingbirds.net. http://www.hummingbirds.net/miller1983.html ↩

  333. Miller, Sarah J.; Inouye, David W. (1983). "Roles of the Wing Whistle in the Territorial Behaviour of Male Broad-tailed Hummingbirds (Selasphorus platycercus)". Animal Behaviour. 31 (3): 689–700. doi:10.1016/S0003-3472(83)80224-3. S2CID 53160649. Retrieved 13 July 2014 – via hummingbirds.net. http://www.hummingbirds.net/miller1983.html ↩

  334. Miller, Sarah J.; Inouye, David W. (1983). "Roles of the Wing Whistle in the Territorial Behaviour of Male Broad-tailed Hummingbirds (Selasphorus platycercus)". Animal Behaviour. 31 (3): 689–700. doi:10.1016/S0003-3472(83)80224-3. S2CID 53160649. Retrieved 13 July 2014 – via hummingbirds.net. http://www.hummingbirds.net/miller1983.html ↩

  335. Lowe, Joe (12 September 2019). "Do hummingbirds migrate?". American Bird Conservancy. Retrieved 8 March 2023. https://abcbirds.org/blog/do-hummingbirds-migrate/ ↩

  336. Godshalk, Katrina. "Hummingbird migration". High Country Gardens. Retrieved 16 January 2023. https://www.highcountrygardens.com/gardening/best-plants-hummingbird-migration ↩

  337. López-Segoviano, Gabriel; Arenas-Navarro, Maribel; Vega, Ernesto; Arizmendi, Maria del Coro (2018). "Hummingbird migration and flowering synchrony in the temperate forests of northwestern Mexico". PeerJ. 6: e5131. doi:10.7717/peerj.5131. PMC 6037137. PMID 30002968. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6037137 ↩

  338. López-Segoviano, Gabriel; Arenas-Navarro, Maribel; Vega, Ernesto; Arizmendi, Maria del Coro (2018). "Hummingbird migration and flowering synchrony in the temperate forests of northwestern Mexico". PeerJ. 6: e5131. doi:10.7717/peerj.5131. PMC 6037137. PMID 30002968. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6037137 ↩

  339. "Hummingbird migration". Hummingbird Central. 2023. Retrieved 28 August 2018. https://www.hummingbirdcentral.com/hummingbird-migration.htm ↩

  340. "Hummingbird migration". Hummingbird Central. 2023. Retrieved 28 August 2018. https://www.hummingbirdcentral.com/hummingbird-migration.htm ↩

  341. "Hummingbird migration". Hummingbird Central. 2023. Retrieved 28 August 2018. https://www.hummingbirdcentral.com/hummingbird-migration.htm ↩

  342. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  343. "Hummingbird migration". Hummingbird Central. 2023. Retrieved 28 August 2018. https://www.hummingbirdcentral.com/hummingbird-migration.htm ↩

  344. "Hummingbird migration". Hummingbird Central. 2023. Retrieved 28 August 2018. https://www.hummingbirdcentral.com/hummingbird-migration.htm ↩

  345. "Hummingbird migration". Hummingbird Central. 2023. Retrieved 28 August 2018. https://www.hummingbirdcentral.com/hummingbird-migration.htm ↩

  346. "Rufous hummingbird". Cornell University Laboratory of Ornithology. 2023. Retrieved 29 April 2023. http://www.allaboutbirds.org/guide/Rufous_Hummingbird/lifehistory ↩

  347. "Rufous hummingbird". Cornell University Laboratory of Ornithology. 2023. Retrieved 29 April 2023. http://www.allaboutbirds.org/guide/Rufous_Hummingbird/lifehistory ↩

  348. "Rufous hummingbird". Cornell University Laboratory of Ornithology. 2023. Retrieved 29 April 2023. http://www.allaboutbirds.org/guide/Rufous_Hummingbird/lifehistory ↩

  349. Lowe, Joe (12 September 2019). "Do hummingbirds migrate?". American Bird Conservancy. Retrieved 8 March 2023. https://abcbirds.org/blog/do-hummingbirds-migrate/ ↩

  350. "Rufous hummingbird". Cornell University Laboratory of Ornithology. 2023. Retrieved 29 April 2023. http://www.allaboutbirds.org/guide/Rufous_Hummingbird/lifehistory ↩

  351. "Rufous hummingbird". Cornell University Laboratory of Ornithology. 2023. Retrieved 29 April 2023. http://www.allaboutbirds.org/guide/Rufous_Hummingbird/lifehistory ↩

  352. "Map of rufous hummingbird migration, Spring 2023". Journey North, Annenberg Learner. 29 April 2023. Retrieved 29 April 2023. https://maps.journeynorth.org/map/?map=hummingbird-rufous-first&year=2023 ↩

  353. "Rufous hummingbird". Cornell University Laboratory of Ornithology. 2023. Retrieved 29 April 2023. http://www.allaboutbirds.org/guide/Rufous_Hummingbird/lifehistory ↩

  354. McKinney, A.M.; Caradonna, P.J.; Inouye, D.W.; Barr, B; Bertelsen, C.D.; Waser, N.M. (2012). "Asynchronous changes in phenology of migrating broad-tailed hummingbirds and their early-season nectar resources" (PDF). Ecology. 93 (9): 1987–993. Bibcode:2012Ecol...93.1987M. doi:10.1890/12-0255.1. PMID 23094369. https://pure.au.dk/ws/files/83236748/McKinney_et_al._2012_with_cover.pdf ↩

  355. "Hummingbird". Encyclopaedia Britannica. 2023. Retrieved 7 March 2023. https://www.britannica.com/animal/hummingbird ↩

  356. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  357. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  358. Abrahamczyk, Stefan; Kessler, Michael (12 February 2010). "Hummingbird diversity, food niche characters, and assemblage composition along a latitudinal precipitation gradient in the Bolivian lowlands". Journal of Ornithology. 151 (3). Springer Science and Business Media LLC: 615–625. Bibcode:2010JOrni.151..615A. doi:10.1007/s10336-010-0496-x. S2CID 25235280. https://link.springer.com/article/10.1007/s10336-010-0496-x ↩

  359. PYKE, GRAHAM H. (1980). "The foraging behaviour of Australian honeyeaters: a review and some comparisons with hummingbirds". Austral Ecology. 5 (4). Wiley: 343–369. Bibcode:1980AusEc...5..343P. doi:10.1111/j.1442-9993.1980.tb01258.x. https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1442-9993.1980.tb01258.x ↩

  360. Spence, Austin R; Wilson Rankin, Erin E; Tingley, Morgan W (3 December 2021). "DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds". Ornithology. 139 (1). Oxford University Press (OUP). doi:10.1093/ornithology/ukab074. https://academic.oup.com/auk/article/139/1/ukab074/6429138 ↩

  361. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  362. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  363. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  364. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  365. Abrahamczyk, Stefan; Kessler, Michael (12 February 2010). "Hummingbird diversity, food niche characters, and assemblage composition along a latitudinal precipitation gradient in the Bolivian lowlands". Journal of Ornithology. 151 (3). Springer Science and Business Media LLC: 615–625. Bibcode:2010JOrni.151..615A. doi:10.1007/s10336-010-0496-x. S2CID 25235280. https://link.springer.com/article/10.1007/s10336-010-0496-x ↩

  366. Spence, Austin R; Wilson Rankin, Erin E; Tingley, Morgan W (3 December 2021). "DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds". Ornithology. 139 (1). Oxford University Press (OUP). doi:10.1093/ornithology/ukab074. https://academic.oup.com/auk/article/139/1/ukab074/6429138 ↩

  367. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  368. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  369. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  370. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  371. Spence, Austin R; Wilson Rankin, Erin E; Tingley, Morgan W (3 December 2021). "DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds". Ornithology. 139 (1). Oxford University Press (OUP). doi:10.1093/ornithology/ukab074. https://academic.oup.com/auk/article/139/1/ukab074/6429138 ↩

  372. Toledo, MCB.; Moreira, DM. (2008). "Analysis of the feeding habits of the swallow-tailed hummingbird, Eupetomena macroura (Gmelin, 1788), in an urban park in southeastern Brazil". Brazilian Journal of Biology. 68 (2). FapUNIFESP (SciELO): 419–426. doi:10.1590/s1519-69842008000200027. PMID 18660974. https://doi.org/10.1590%2Fs1519-69842008000200027 ↩

  373. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  374. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  375. Brice, Ann T.; Grau, C. Richard (1991). "Protein Requirements of Costa's Hummingbirds Calypte costae". Physiological Zoology. 64 (2). University of Chicago Press: 611–626. doi:10.1086/physzool.64.2.30158193. S2CID 87673164. https://www.journals.uchicago.edu/doi/abs/10.1086/physzool.64.2.30158193 ↩

  376. Brice, Ann T.; Grau, C. Richard (1991). "Protein Requirements of Costa's Hummingbirds Calypte costae". Physiological Zoology. 64 (2). University of Chicago Press: 611–626. doi:10.1086/physzool.64.2.30158193. S2CID 87673164. https://www.journals.uchicago.edu/doi/abs/10.1086/physzool.64.2.30158193 ↩

  377. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  378. Spence, Austin R; Wilson Rankin, Erin E; Tingley, Morgan W (3 December 2021). "DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds". Ornithology. 139 (1). Oxford University Press (OUP). doi:10.1093/ornithology/ukab074. https://academic.oup.com/auk/article/139/1/ukab074/6429138 ↩

  379. Brice, Ann T.; Grau, C. Richard (1991). "Protein Requirements of Costa's Hummingbirds Calypte costae". Physiological Zoology. 64 (2). University of Chicago Press: 611–626. doi:10.1086/physzool.64.2.30158193. S2CID 87673164. https://www.journals.uchicago.edu/doi/abs/10.1086/physzool.64.2.30158193 ↩

  380. Yanega, Gregor M.; Rubega, Margaret A. (2004). "Feeding mechanisms: Hummingbird jaw bends to aid insect capture". Nature. 428 (6983): 615. Bibcode:2004Natur.428..615Y. doi:10.1038/428615a. PMID 15071586. S2CID 4423676. https://doi.org/10.1038%2F428615a ↩

  381. Carroll, Scott P.; Moore, Laurel (1993). "Hummingbirds take their vitamins". Animal Behaviour. 46 (4). Elsevier BV: 817–820. doi:10.1006/anbe.1993.1261. S2CID 54417626. https://www.sciencedirect.com/science/article/abs/pii/S0003347283712613 ↩

  382. Brice, Ann T.; Grau, C. Richard (1991). "Protein Requirements of Costa's Hummingbirds Calypte costae". Physiological Zoology. 64 (2). University of Chicago Press: 611–626. doi:10.1086/physzool.64.2.30158193. S2CID 87673164. https://www.journals.uchicago.edu/doi/abs/10.1086/physzool.64.2.30158193 ↩

  383. Chavez-Ramirez, Felipe; Dowd, McAlister (1992). "Arthropod Feeding by Two Dominican Hummingbird Species". The Wilson Bulletin. 104 (4). Wilson Ornithological Society: 743–747. JSTOR 4163229. Retrieved 2 September 2023. http://www.jstor.org/stable/4163229 ↩

  384. Kuban, Joseph F.; Neill, Robert L. (1980). "Feeding Ecology of Hummingbirds in the Highlands of the Chisos Mountains, Texas". The Condor. 82 (2). Oxford University Press (OUP): 180. doi:10.2307/1367475. JSTOR 1367475. https://academic.oup.com/condor/article-abstract/82/2/180/5204713 ↩

  385. Toledo, MCB.; Moreira, DM. (2008). "Analysis of the feeding habits of the swallow-tailed hummingbird, Eupetomena macroura (Gmelin, 1788), in an urban park in southeastern Brazil". Brazilian Journal of Biology. 68 (2). FapUNIFESP (SciELO): 419–426. doi:10.1590/s1519-69842008000200027. PMID 18660974. https://doi.org/10.1590%2Fs1519-69842008000200027 ↩

  386. Montgomerie, Robert D.; Redsell, Catherine A. (1980). "A Nesting Hummingbird Feeding Solely on Arthropods" (PDF). The Condor. 82 (4). Oxford University Press (OUP): 463. doi:10.2307/1367577. JSTOR 1367577. https://sora.unm.edu/sites/default/files/journals/condor/v082n04/p0463-p0464.pdf ↩

  387. Toledo, MCB.; Moreira, DM. (2008). "Analysis of the feeding habits of the swallow-tailed hummingbird, Eupetomena macroura (Gmelin, 1788), in an urban park in southeastern Brazil". Brazilian Journal of Biology. 68 (2). FapUNIFESP (SciELO): 419–426. doi:10.1590/s1519-69842008000200027. PMID 18660974. https://doi.org/10.1590%2Fs1519-69842008000200027 ↩

  388. Chavez-Ramirez, Felipe; Dowd, McAlister (1992). "Arthropod Feeding by Two Dominican Hummingbird Species". The Wilson Bulletin. 104 (4). Wilson Ornithological Society: 743–747. JSTOR 4163229. Retrieved 2 September 2023. http://www.jstor.org/stable/4163229 ↩

  389. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  390. Yanega, Gregor M.; Rubega, Margaret A. (2004). "Feeding mechanisms: Hummingbird jaw bends to aid insect capture". Nature. 428 (6983): 615. Bibcode:2004Natur.428..615Y. doi:10.1038/428615a. PMID 15071586. S2CID 4423676. https://doi.org/10.1038%2F428615a ↩

  391. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  392. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  393. Spence, Austin R; Wilson Rankin, Erin E; Tingley, Morgan W (3 December 2021). "DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds". Ornithology. 139 (1). Oxford University Press (OUP). doi:10.1093/ornithology/ukab074. https://academic.oup.com/auk/article/139/1/ukab074/6429138 ↩

  394. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  395. Spence, Austin R; Wilson Rankin, Erin E; Tingley, Morgan W (3 December 2021). "DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds". Ornithology. 139 (1). Oxford University Press (OUP). doi:10.1093/ornithology/ukab074. https://academic.oup.com/auk/article/139/1/ukab074/6429138 ↩

  396. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  397. Spence, Austin R; Wilson Rankin, Erin E; Tingley, Morgan W (3 December 2021). "DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds". Ornithology. 139 (1). Oxford University Press (OUP). doi:10.1093/ornithology/ukab074. https://academic.oup.com/auk/article/139/1/ukab074/6429138 ↩

  398. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  399. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  400. Montgomerie, Robert D.; Redsell, Catherine A. (1980). "A Nesting Hummingbird Feeding Solely on Arthropods" (PDF). The Condor. 82 (4). Oxford University Press (OUP): 463. doi:10.2307/1367577. JSTOR 1367577. https://sora.unm.edu/sites/default/files/journals/condor/v082n04/p0463-p0464.pdf ↩

  401. Toledo, MCB.; Moreira, DM. (2008). "Analysis of the feeding habits of the swallow-tailed hummingbird, Eupetomena macroura (Gmelin, 1788), in an urban park in southeastern Brazil". Brazilian Journal of Biology. 68 (2). FapUNIFESP (SciELO): 419–426. doi:10.1590/s1519-69842008000200027. PMID 18660974. https://doi.org/10.1590%2Fs1519-69842008000200027 ↩

  402. Brice, Ann T.; Grau, C. Richard (1991). "Protein Requirements of Costa's Hummingbirds Calypte costae". Physiological Zoology. 64 (2). University of Chicago Press: 611–626. doi:10.1086/physzool.64.2.30158193. S2CID 87673164. https://www.journals.uchicago.edu/doi/abs/10.1086/physzool.64.2.30158193 ↩

  403. PYKE, GRAHAM H. (1980). "The foraging behaviour of Australian honeyeaters: a review and some comparisons with hummingbirds". Austral Ecology. 5 (4). Wiley: 343–369. Bibcode:1980AusEc...5..343P. doi:10.1111/j.1442-9993.1980.tb01258.x. https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1442-9993.1980.tb01258.x ↩

  404. Montgomerie, Robert D.; Redsell, Catherine A. (1980). "A Nesting Hummingbird Feeding Solely on Arthropods" (PDF). The Condor. 82 (4). Oxford University Press (OUP): 463. doi:10.2307/1367577. JSTOR 1367577. https://sora.unm.edu/sites/default/files/journals/condor/v082n04/p0463-p0464.pdf ↩

  405. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  406. Weathers, Wesley W.; Stiles, F. Gary (1989). "Energetics and Water Balance in Free-Living Tropical Hummingbirds". The Condor. 91 (2). Oxford University Press (OUP): 324. doi:10.2307/1368310. JSTOR 1368310. https://academic.oup.com/condor/article-abstract/91/2/324/5189260 ↩

  407. Stiles, F. Gary (1995). "Behavioral, Ecological and Morphological Correlates of Foraging for Arthropods by the Hummingbirds of a Tropical Wet Forest". The Condor. 97 (4). Oxford University Press (OUP): 853–878. doi:10.2307/1369527. JSTOR 1369527. https://academic.oup.com/condor/article-abstract/97/4/853/5126159 ↩

  408. Céspedes, Laura N.; Pavan, Lucas I.; Hazlehurst, Jenny A.; Jankowski, Jill E. (9 April 2019). "The behavior and diet of the Shining Sunbeam (Aglaeactis cupripennis): A territorial high-elevation hummingbird". The Wilson Journal of Ornithology. 131 (1). Wilson Ornithological Society: 24. doi:10.1676/18-79. S2CID 91263467. https://meridian.allenpress.com/wjo/article-abstract/131/1/24/430191/The-behavior-and-diet-of-the-Shining-Sunbeam ↩

  409. Chavez-Ramirez, Felipe; Dowd, McAlister (1992). "Arthropod Feeding by Two Dominican Hummingbird Species". The Wilson Bulletin. 104 (4). Wilson Ornithological Society: 743–747. JSTOR 4163229. Retrieved 2 September 2023. http://www.jstor.org/stable/4163229 ↩

  410. del Hoyo, Josep; Andrew, Elliott; Sargatal, Jordi (1999). Handbook of the Birds of the World Vol. 5. Barn-owls to Hummingbirds. Barcelona: Lynx Edicions. pp. 475–680. ISBN 84-87334-25-3. 84-87334-25-3 ↩

  411. Chavez-Ramirez, Felipe; Dowd, McAlister (1992). "Arthropod Feeding by Two Dominican Hummingbird Species". The Wilson Bulletin. 104 (4). Wilson Ornithological Society: 743–747. JSTOR 4163229. Retrieved 2 September 2023. http://www.jstor.org/stable/4163229 ↩

  412. Abrahamczyk, Stefan; Kessler, Michael (12 February 2010). "Hummingbird diversity, food niche characters, and assemblage composition along a latitudinal precipitation gradient in the Bolivian lowlands". Journal of Ornithology. 151 (3). Springer Science and Business Media LLC: 615–625. Bibcode:2010JOrni.151..615A. doi:10.1007/s10336-010-0496-x. S2CID 25235280. https://link.springer.com/article/10.1007/s10336-010-0496-x ↩

  413. Spence, Austin R; Wilson Rankin, Erin E; Tingley, Morgan W (3 December 2021). "DNA metabarcoding reveals broadly overlapping diets in three sympatric North American hummingbirds". Ornithology. 139 (1). Oxford University Press (OUP). doi:10.1093/ornithology/ukab074. https://academic.oup.com/auk/article/139/1/ukab074/6429138 ↩

  414. Unwin, Mike (2011). The Atlas of Birds: Diversity, Behavior, and Conservation. Princeton University Press. p. 57. ISBN 978-1-4008-3825-7. 978-1-4008-3825-7 ↩

  415. Stevens, C. Edward; Hume, Ian D. (2004). Comparative Physiology of the Vertebrate Digestive System. Cambridge University Press. p. 126. ISBN 978-0-521-61714-7. 978-0-521-61714-7 ↩

  416. Diamond, Jared M.; Karasov, William H.; Phan, Duong; Carpenter, F. Lynn (1986). "Digestive physiology is a determinant of foraging bout frequency in hummingbirds". Nature. 320 (6057): 62–3. Bibcode:1986Natur.320...62D. doi:10.1038/320062a0. PMID 3951548. S2CID 4363635. https://www.nature.com/articles/320062a0 ↩

  417. Stonich, Kathryn (26 April 2021). "Hummingbirds of the United States: A Photo List of All Species". American Bird Conservancy. Retrieved 7 March 2023. https://abcbirds.org/blog21/types-of-hummingbirds/ ↩

  418. Ward, B.J.; Day, L.B.; Wilkening, S.R.; et al. (2012). "Hummingbirds have a greatly enlarged hippocampal formation". Biology Letters. 8 (4): 657–659. doi:10.1098/rsbl.2011.1180. PMC 3391440. PMID 22357941. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3391440 ↩

  419. Berns, Chelsea M.; Adams, Dean C. (11 November 2012). "Becoming Different But Staying Alike: Patterns of Sexual Size and Shape Dimorphism in Bills of Hummingbirds". Evolutionary Biology. 40 (2): 246–260. doi:10.1007/s11692-012-9206-3. ISSN 0071-3260. S2CID 276492. /wiki/Doi_(identifier) ↩

  420. Temeles, Ethan J.; Miller, Jill S.; Rifkin, Joanna L. (12 April 2010). "Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation". Philosophical Transactions of the Royal Society of London B: Biological Sciences. 365 (1543): 1053–063. doi:10.1098/rstb.2009.0284. ISSN 0962-8436. PMC 2830232. PMID 20194168. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830232 ↩

  421. Leimberger, K.G.; Dalsgaard, B.; Tobias, J.A.; Wolf, C.; Betts, M.G. (June 2022). "The evolution, ecology, and conservation of hummingbirds and their interactions with flowering plants". Biological Reviews of the Cambridge Philosophical Society. 97 (3): 923–959. doi:10.1111/brv.12828. hdl:10044/1/94632. PMID 35029017. S2CID 245971244. /wiki/Doi_(identifier) ↩

  422. Rico-Guevara, A.; Rubega, M.A.; Hurme, K.J.; Dudley, R. (2019). "Shifting paradigms in the mechanics of nectar extraction and hummingbird bill morphology". Integrative Organismal Biology. 1 (1): oby006. doi:10.1093/iob/oby006. PMC 7671138. PMID 33791513. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7671138 ↩

  423. Yanega, Gregor M.; Rubega, Margaret A. (2004). "Feeding mechanisms: Hummingbird jaw bends to aid insect capture". Nature. 428 (6983): 615. Bibcode:2004Natur.428..615Y. doi:10.1038/428615a. PMID 15071586. S2CID 4423676. https://doi.org/10.1038%2F428615a ↩

  424. Boehm, M.M.A.; Guevara-Apaza, D.; Jankowski, J.E.; Cronk, Q.C.B. (July 2022). "Floral phenology of an Andean bellflower and pollination by buff-tailed sicklebill hummingbird". Ecology and Evolution. 12 (6): e8988. Bibcode:2022EcoEv..12E8988B. doi:10.1002/ece3.8988. PMC 9168340. PMID 35784085. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9168340 ↩

  425. Leimberger, K.G.; Dalsgaard, B.; Tobias, J.A.; Wolf, C.; Betts, M.G. (June 2022). "The evolution, ecology, and conservation of hummingbirds and their interactions with flowering plants". Biological Reviews of the Cambridge Philosophical Society. 97 (3): 923–959. doi:10.1111/brv.12828. hdl:10044/1/94632. PMID 35029017. S2CID 245971244. /wiki/Doi_(identifier) ↩

  426. Betts, M.G.; Hadley, A.S.; Kress, W.J. (March 2015). "Pollinator recognition by a keystone tropical plant". Proceedings of the National Academy of Sciences of the United States of America. 112 (11): 3433–8. Bibcode:2015PNAS..112.3433B. doi:10.1073/pnas.1419522112. PMC 4371984. PMID 25733902. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4371984 ↩

  427. "Fiery-tailed awlbills". Beauty of Birds. 16 September 2021. Retrieved 8 March 2023. https://beautyofbirds.com/fierytailedawlbillhummingbirds/ ↩

  428. Baldwin, Maude W.; Toda, Yasuka; Nakagita, Tomoya; O'Connell, Mary J.; Klasing, Kirk C.; Misaka, Takumi; Edwards, Scott V.; Liberles, Stephen D. (2014). "Sensory biology. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor". Science. 345 (6199): 929–933. Bibcode:2014Sci...345..929B. doi:10.1126/science.1255097. PMC 4302410. PMID 25146290. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4302410 ↩

  429. Li, X. (2009). "T1R receptors mediate mammalian sweet and umami taste". American Journal of Clinical Nutrition. 90 (3): 733S – 37S. doi:10.3945/ajcn.2009.27462G. PMID 19656838. https://doi.org/10.3945%2Fajcn.2009.27462G ↩

  430. Baldwin, Maude W.; Toda, Yasuka; Nakagita, Tomoya; O'Connell, Mary J.; Klasing, Kirk C.; Misaka, Takumi; Edwards, Scott V.; Liberles, Stephen D. (2014). "Sensory biology. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor". Science. 345 (6199): 929–933. Bibcode:2014Sci...345..929B. doi:10.1126/science.1255097. PMC 4302410. PMID 25146290. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4302410 ↩

  431. Baldwin, Maude W.; Toda, Yasuka; Nakagita, Tomoya; O'Connell, Mary J.; Klasing, Kirk C.; Misaka, Takumi; Edwards, Scott V.; Liberles, Stephen D. (2014). "Sensory biology. Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor". Science. 345 (6199): 929–933. Bibcode:2014Sci...345..929B. doi:10.1126/science.1255097. PMC 4302410. PMID 25146290. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4302410 ↩

  432. Rico-Guevara, Alejandro; Fan, Tai-Hsi; Rubega, Margaret A. (22 August 2015). "Hummingbird tongues are elastic micropumps". Proceedings of the Royal Society B. 282 (1813): 20151014. doi:10.1098/rspb.2015.1014. ISSN 0962-8452. PMC 4632618. PMID 26290074. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632618 ↩

  433. Frank, David; Gorman, James (8 September 2015). "ScienceTake | The hummingbird's tongue". The New York Times. ISSN 0362-4331. Retrieved 10 September 2015. https://www.nytimes.com/video/science/100000003892113/the-hummingbirds-tongue.html ↩

  434. Kim, W.; Peaudecerf, F.; Baldwin, M.W.; Bush, J.W. (2012). "The hummingbird's tongue: A self-assembling capillary syphon". Proceedings of the Royal Society B: Biological Sciences. 279 (1749): 4990–996. doi:10.1098/rspb.2012.1837. PMC 3497234. PMID 23075839. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3497234 ↩

  435. Rico-Guevara, A.; Rubega, M.A. (2011). "The hummingbird tongue is a fluid trap, not a capillary tube". Proceedings of the National Academy of Sciences. 108 (23): 9356–360. Bibcode:2011PNAS..108.9356R. doi:10.1073/pnas.1016944108. PMC 3111265. PMID 21536916. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111265 ↩

  436. Mosher, D. (2 May 2011). "High-speed video shows how hummingbirds really drink". Wired. Retrieved 13 August 2022. https://www.wired.com/wiredscience/2011/05/hummingbird-tongue-drinking ↩

  437. Rico-Guevara, Alejandro; Fan, Tai-Hsi; Rubega, Margaret A. (22 August 2015). "Hummingbird tongues are elastic micropumps". Proceedings of the Royal Society B. 282 (1813): 20151014. doi:10.1098/rspb.2015.1014. ISSN 0962-8452. PMC 4632618. PMID 26290074. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632618 ↩

  438. Frank, David; Gorman, James (8 September 2015). "ScienceTake | The hummingbird's tongue". The New York Times. ISSN 0362-4331. Retrieved 10 September 2015. https://www.nytimes.com/video/science/100000003892113/the-hummingbirds-tongue.html ↩

  439. Mosher, D. (2 May 2011). "High-speed video shows how hummingbirds really drink". Wired. Retrieved 13 August 2022. https://www.wired.com/wiredscience/2011/05/hummingbird-tongue-drinking ↩

  440. Gorman, James (8 September 2015). "The hummingbird's tongue: How it works". The New York Times. ISSN 0362-4331. Retrieved 10 September 2015. https://www.nytimes.com/2015/09/08/science/the-hummingbirds-tongue-how-it-works.html ↩

  441. Rico-Guevara, Alejandro; Fan, Tai-Hsi; Rubega, Margaret A. (22 August 2015). "Hummingbird tongues are elastic micropumps". Proceedings of the Royal Society B. 282 (1813): 20151014. doi:10.1098/rspb.2015.1014. ISSN 0962-8452. PMC 4632618. PMID 26290074. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632618 ↩

  442. Frank, David; Gorman, James (8 September 2015). "ScienceTake | The hummingbird's tongue". The New York Times. ISSN 0362-4331. Retrieved 10 September 2015. https://www.nytimes.com/video/science/100000003892113/the-hummingbirds-tongue.html ↩

  443. Kim, W.; Peaudecerf, F.; Baldwin, M.W.; Bush, J.W. (2012). "The hummingbird's tongue: A self-assembling capillary syphon". Proceedings of the Royal Society B: Biological Sciences. 279 (1749): 4990–996. doi:10.1098/rspb.2012.1837. PMC 3497234. PMID 23075839. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3497234 ↩

  444. Stahl, J.M.; Nepi, M.; Galetto, L.; Guimarães, E.; Machado, S.R. (2012). "Functional aspects of floral nectar secretion of Ananas ananassoides, an ornithophilous bromeliad from the Brazilian savanna". Annals of Botany. 109 (7): 1243–252. doi:10.1093/aob/mcs053. PMC 3359915. PMID 22455992. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3359915 ↩

  445. Avalos, G.; Soto, A.; Alfaro, W. (2012). "Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de la Muerte, Costa Rica". Revista de Biología Tropical. 60 (1): 65–73. doi:10.15517/rbt.v60i1.2362. PMID 22458209. https://doi.org/10.15517%2Frbt.v60i1.2362 ↩

  446. "Hummingbird Nectar Recipe". Nationalzoo.si.edu. 22 February 2017. Retrieved 7 September 2022. https://nationalzoo.si.edu/migratory-birds/hummingbird-nectar-recipe ↩

  447. Rousseu, F.; Charette, Y.; Bélisle, M. (2014). "Resource defense and monopolization in a marked population of ruby-throated hummingbirds (Archilochus colubris)". Ecology and Evolution. 4 (6): 776–793. Bibcode:2014EcoEv...4..776R. doi:10.1002/ece3.972. PMC 3967903. PMID 24683460. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3967903 ↩

  448. "How to Make Hummingbird Nectar". Audubon.com. Audubon Society. 14 April 2016. http://www.audubon.org/news/how-make-hummingbird-nectar ↩

  449. "Feeding Hummingbirds". www.kern.audubon.org. Audubon California Kern River Preserve. Archived from the original on 8 April 2022. Retrieved 6 April 2017. https://web.archive.org/web/20220408140247/http://www.kern.audubon.org/hummer_feeding.htm ↩

  450. "Feeders and Feeding Hummingbirds". Faq.gardenweb.com. 9 January 2008. Retrieved 25 January 2009. http://faq.gardenweb.com/faq/lists/hummingbird/2003021845028716.html ↩

  451. "Hummingbird F.A.Q.s from the Southeastern Arizona Bird Observatory". Sabo.org. 25 November 2008. Archived from the original on 2 November 2014. Retrieved 25 January 2009. https://web.archive.org/web/20141102002928/http://sabo.org/hbfaqs.htm#honey ↩

  452. Attracting Hummingbirds |Missouri Department of Conservation Archived 19 April 2012 at the Wayback Machine Retrieved on 2013-04-01 http://mdc.mo.gov/discover-nature/outdoor-recreation/nature-viewing/birding/ruby-throated-hummingbirds ↩

  453. Chambers, Lanny (2016). "Please Don't Use Red Dye". Hummingbirds.net. Retrieved 25 June 2016. http://www.hummingbirds.net/dye.html ↩

  454. Chambers, Lanny (2016). "Please Don't Use Red Dye". Hummingbirds.net. Retrieved 25 June 2016. http://www.hummingbirds.net/dye.html ↩

  455. "Should I Add Red Dye to My Hummingbird Food?". Trochilids.com. Retrieved 20 March 2010. http://www.trochilids.com/dye.html ↩

  456. Williamson, S. L. (2002). A Field Guide to Hummingbirds of North America. Peterson Field Guide Series. Boston: Houghton Mifflin. ISBN 0-618-02496-4. 0-618-02496-4 ↩

  457. Lisney, T.J.; Wylie, D.R.; Kolominsky, J.; Iwaniuk, A.N. (2015). "Eye morphology and retinal topography in hummingbirds (Trochilidae Aves)". Brain, Behavior and Evolution. 86 (3–4): 176–190. doi:10.1159/000441834. PMID 26587582. https://www.karger.com/Article/FullText/441834 ↩

  458. "Hummingbirds See Red". US National Audubon Society. 28 May 2013. Retrieved 23 April 2017. http://www.audubon.org/news/hummingbirds-see-red ↩

  459. "Hummingbirds take no notice of flower color". Phys.org. 16 March 2012. Retrieved 22 April 2017. https://phys.org/news/2012-03-hummingbirds.html ↩

  460. Hurly, T.A.; Franz, S; Healy, S.D. (2010). "Do rufous hummingbirds (Selasphorus rufus) use visual beacons?". Animal Cognition. 13 (2): 377–383. doi:10.1007/s10071-009-0280-6. PMID 19768647. S2CID 9189780. /wiki/Doi_(identifier) ↩

  461. Hurly, T.A.; Fox, T.A.O.; Zwueste, D.M.; Healy, S.D. (2014). "Wild hummingbirds rely on landmarks not geometry when learning an array of flowers" (PDF). Animal Cognition. 17 (5): 1157–165. doi:10.1007/s10071-014-0748-x. hdl:10023/6422. PMID 24691650. S2CID 15169177. https://research-repository.st-andrews.ac.uk/bitstream/10023/6422/1/Hurly_et_al_Anim_Cog_14.pdf ↩

  462. Hornsby, Mark A.W.; Healy, Susan D.; Hurly, T. Andrew (2017). "Wild hummingbirds can use the geometry of a flower array". Behavioural Processes. 139: 33–37. doi:10.1016/j.beproc.2017.01.019. hdl:10023/12652. ISSN 0376-6357. PMID 28161360. S2CID 10692583. /wiki/Doi_(identifier) ↩

  463. Herrera, G; Zagal, J. C.; Diaz, M; Fernández, M. J.; Vielma, A; Cure, M; Martinez, J; Bozinovic, F; Palacios, A. G. (2008). "Spectral sensitivities of photoreceptors and their role in colour discrimination in the green-backed firecrown hummingbird (Sephanoides sephaniodes)". Journal of Comparative Physiology A. 194 (9): 785–794. doi:10.1007/s00359-008-0349-8. hdl:10533/142104. PMID 18584181. S2CID 7491787. http://americanae.aecid.es/americanae/es/registros/registro.do?tipoRegistro=MTD&idBib=3262327 ↩

  464. Herrera, G; Zagal, J. C.; Diaz, M; Fernández, M. J.; Vielma, A; Cure, M; Martinez, J; Bozinovic, F; Palacios, A. G. (2008). "Spectral sensitivities of photoreceptors and their role in colour discrimination in the green-backed firecrown hummingbird (Sephanoides sephaniodes)". Journal of Comparative Physiology A. 194 (9): 785–794. doi:10.1007/s00359-008-0349-8. hdl:10533/142104. PMID 18584181. S2CID 7491787. http://americanae.aecid.es/americanae/es/registros/registro.do?tipoRegistro=MTD&idBib=3262327 ↩

  465. "Hummingbirds See Red". US National Audubon Society. 28 May 2013. Retrieved 23 April 2017. http://www.audubon.org/news/hummingbirds-see-red ↩

  466. Herrera, G; Zagal, J. C.; Diaz, M; Fernández, M. J.; Vielma, A; Cure, M; Martinez, J; Bozinovic, F; Palacios, A. G. (2008). "Spectral sensitivities of photoreceptors and their role in colour discrimination in the green-backed firecrown hummingbird (Sephanoides sephaniodes)". Journal of Comparative Physiology A. 194 (9): 785–794. doi:10.1007/s00359-008-0349-8. hdl:10533/142104. PMID 18584181. S2CID 7491787. http://americanae.aecid.es/americanae/es/registros/registro.do?tipoRegistro=MTD&idBib=3262327 ↩

  467. Kim, Ashley Y.; Rankin, David T.; Rankin, Erin E. Wilson (2021). "What is that smell? Hummingbirds avoid foraging on resources with defensive insect compounds". Behavioral Ecology and Sociobiology. 75 (9): 132. Bibcode:2021BEcoS..75..132K. doi:10.1007/s00265-021-03067-4. ISSN 0340-5443. https://doi.org/10.1007%2Fs00265-021-03067-4 ↩

  468. Werness, Hope B.; Benedict, Joanne H.; Thomas, Scott; Ramsay-Lozano, Tiffany (2004). The Continuum Encyclopedia of Animal Symbolism in Art. Continuum International Publishing Group. p. 229. ISBN 978-0-8264-1525-7. 978-0-8264-1525-7 ↩

  469. "Huitzilopochtli". Encyclopaedia Britannica. 2023. Retrieved 5 March 2023. https://www.britannica.com/topic/Huitzilopochtli ↩

  470. "Huitzilopochtli". Encyclopaedia Britannica. 2023. Retrieved 5 March 2023. https://www.britannica.com/topic/Huitzilopochtli ↩

  471. MacDonald, Fiona (2008). How to Be an Aztec Warrior. National Geographic Books. p. 25. ISBN 978-1-4263-0168-1. 978-1-4263-0168-1 ↩

  472. "Huitzilopochtli". Encyclopaedia Britannica. 2023. Retrieved 5 March 2023. https://www.britannica.com/topic/Huitzilopochtli ↩

  473. Golomb, Jason (28 September 2019). "Nasca lines". National Geographic. Archived from the original on 28 September 2019. Retrieved 5 March 2023. https://web.archive.org/web/20190928050205/https://www.nationalgeographic.com/history/archaeology/nasca-lines/ ↩

  474. "National Symbols of Trinidad and Tobago". National Library of Trinidad and Tobago, Port of Spain. 2016. Archived from the original on 7 May 2016. Retrieved 18 April 2016. https://web.archive.org/web/20160507114705/http://www.nalis.gov.tt/Research/SubjectGuide/NationalSymbols/tabid/215/Default.aspx?PageContentMode=1 ↩

  475. "Coins of Trinidad and Tobago". Central Bank of Trinidad and Tobago, Port of Spain. 2015. Archived from the original on 7 February 2017. Retrieved 18 April 2016. https://web.archive.org/web/20170207120816/http://www.central-bank.org.tt/content/coins ↩

  476. "Brand Refresh: Introducing the new Caribbean Airlines". Caribbean Airlines. 1 March 2020. Retrieved 5 March 2023. https://www.caribbean-airlines.com/#/pages/brand-refresh ↩

  477. "National Awards (The Hummingbird Medal)". Office of the President, Republic of Trinidad and Tobago. 2025. Retrieved 22 February 2025. https://otp.tt/trinidad-and-tobago/national-awards/ ↩

  478. "Sierra Azul Preserve - Overview". Midpeninsula Regional Open Space District. 2021. Retrieved 5 March 2023. http://www.openspace.org/preserves/sierra-azul#tabs-preserve_tabs-middle-4 ↩

  479. "Hummingbird Original". Gibson Brands, Inc. 2023. Retrieved 5 March 2023. https://www.gibson.com/en-US/Acoustic-Guitar/ACCFR6729/Antique-Natural ↩

  480. Garcia, Alexander (26 January 2017). "Connie Jiménez dressed as a hummingbird in the Miss Universe preliminary competition (translated from Spanish)". El Commercio. Retrieved 5 March 2023. https://www.elcomercio.com/tendencias/entretenimiento/conniejimenez-missecuador-missuniverso-trajes-competenciapreliminar.html ↩