A | B | C | D | E | F | G | H | CH | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
| Hummingbird Temporal range: Rupelian
| |
|---|---|
| |
| Four hummingbirds from Trinidad and Tobago | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Clade: | Strisores |
| Order: | Apodiformes |
| Family: | Trochilidae Vigors, 1825 |
| Type genus | |
| Trochilus | |
| Subfamilies | |
|
Subfamiles:
| |
Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With approximately 366 species and 113 genera,[1] they occur from Alaska to Tierra del Fuego, but most species are found in Central and South America.[2] As of 2024, 21 hummingbird species are listed as endangered or critically endangered, with numerous species declining in population.[3][4]
Hummingbirds have varied specialized characteristics to enable rapid, maneuverable flight: exceptional metabolic capacity, adaptations to high altitude, sensitive visual and communication abilities, and long-distance migration in some species. Among all birds, male hummingbirds have the widest diversity of plumage color, particularly in blues, greens, and purples.[5] Hummingbirds are the smallest mature birds, measuring 7.5–13 cm (3–5 in) in length. The smallest is the 5 cm (2.0 in) bee hummingbird, which weighs less than 2.0 g (0.07 oz), and the largest is the 23 cm (9 in) giant hummingbird, weighing 18–24 grams (0.63–0.85 oz). Noted for long beaks, hummingbirds are specialized for feeding on flower nectar, but all species also consume small insects.
They are known as hummingbirds because of the humming sound created by their beating wings, which flap at high frequencies audible to other birds and humans. They hover at rapid wing-flapping rates, which vary from around 12 beats per second in the largest species to 80 per second in small hummingbirds.
Hummingbirds have the highest mass-specific metabolic rate of any homeothermic animal.[6][7] To conserve energy when food is scarce and at night when not foraging, they can enter torpor, a state similar to hibernation, and slow their metabolic rate to 1⁄15 of its normal rate.[7][8] While most hummingbirds do not migrate, the rufous hummingbird has one of the longest migrations among birds, traveling twice per year between Alaska and Mexico, a distance of about 3,900 miles (6,300 km).
Hummingbirds split from their sister group, the swifts and treeswifts, around 42 million years ago.[9] The oldest known fossil hummingbird is Eurotrochilus, from the Rupelian Stage of Early Oligocene Europe.[10]
Description
_adult_male_non-breeding.jpg)
Hummingbirds are the smallest known and smallest living avian theropod dinosaurs.[11][12][13] 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.[14]
Morphology
Across the estimated 366 species, hummingbird weights range from as small as 2 grams (0.071 oz) to as large as 20 grams (0.71 oz).[14][15] They have characteristic long, narrow beaks (bills) which may be straight (of varying lengths) or highly curved.[14][15] 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.[14][16]
Hummingbirds have compact bodies with relatively long, bladelike wings having anatomical structure enabling helicopter-like flight in any direction, including the ability to hover.[14][15] Particularly while hovering, the wing beats produce the humming sounds, which function to alert other birds.[14] In some species, the tail feathers produce sounds used by males during courtship flying.[14][15] Hummingbirds have extremely rapid wing-beats as high as 80 per second, supported by a high metabolic rate dependent on foraging for sugars from flower nectar.[7][15]
.jpg)
Hummingbird legs are short with no knees, and have feet with three toes pointing forward and one backward – the hallux.[17][18] The toes of hummingbirds are formed as claws with ridged inner surfaces to aid gripping onto flower stems or petals.[18] 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.[17][18]
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.[19] During flight, hummingbird feet are tucked up under the body, enabling optimal aerodynamics and maneuverability.[18]
Of those species that have been measured during flight, the top flight speeds of hummingbirds exceed 15 m/s (54 km/h; 34 mph).[16] 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).[20][21]
The sexes differ in feather coloration, with males having distinct brilliance and ornamentation of head, neck, wing, and breast feathers.[14][15] 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.[14]
Life cycle
.jpg)
.jpg)
Hummingbirds begin mating when they are a year old.[22] Sex occurs over 3–5 seconds when the male joins its cloaca with the female's, passing sperm to fertilize the female's eggs.[22]
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).[14][15] Typically, two pea-shaped white eggs (image) – the smallest of any bird – are incubated over 2–3 weeks in breeding season.[14][15] Fed by regurgitation only from the mother, the chicks fledge about 3 weeks after hatching.[15][23]
.jpg)
The average lifespan of a ruby-throated hummingbird is estimated to be 3–5 years, with most deaths occurring in yearlings,[23] although one banded ruby-throated hummingbird lived for 9 years and 2 months.[24] Bee hummingbirds live 7–10 years.[16]
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.[2] Several species exist only in the thousands or hundreds.[2]
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.[3] Two species – the Brace's emerald (Riccordia bracei) and Caribbean emerald (Riccordia elegans) – have been declared extinct.[3]
.jpg)
Of the 15 species of North American hummingbirds that inhabit the United States and Canada,[2] several have changed their range of distribution, while others showed declines in numbers since the 1970s,[2][4] 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.[2][4][25] The ruby-throated hummingbird population – the most populous North American hummingbird – decreased by 17% over the early 21st century.[4] 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.[2][25] By contrast, Anna's hummingbirds had large population growth at an accelerating rate since 2010,[4] and expanded their range northward to reside year-round in cold winter climates.[26]
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,[27] but are not related to hummingbirds, as their resemblance is due to convergent evolution.[28]
The hummingbird moth has flying and feeding characteristics similar to those of a hummingbird.[29] Hummingbirds may be mistaken for hummingbird hawk-moths, which are large, flying insects with hovering capabilities, and exist only in Eurasia.[27]
Range
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).[30]
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,[31] Colombia alone has more than 160[32] and the comparably small Ecuador has about 130 species.[33]
Taxonomy and systematics
The family Trochilidae was introduced in 1825 by Irish zoologist Nicholas Aylward Vigors with Trochilus as the type genus.[34][35] 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.[36] Hummingbirds' 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.[37]
As of 2023, 366 hummingbird species have been identified.[1] They have been traditionally divided into two subfamilies: the hermits (subfamily Phaethornithinae) and the typical hummingbirds (subfamily Trochilinae, all the others). Molecular phylogenetic studies have shown, though, that the hermits are sister to the topazes, making the former definition of the 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.[9] 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).[9][1]
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.[37][10]
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.[38]
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.[39]
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.[9] 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.[10][40][41]
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.[9]
A map of the hummingbird family tree – reconstructed from analysis of 284 species – shows rapid diversification from 22 million years ago.[42] 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.[9][43][44]
Molecular phylogenetic studies of the hummingbirds have shown that the family is composed of nine major clades.[43][9] 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.[45]
Molecular phylogenetic studies determined the relationships between the major groups of hummingbirds.[9][44] In the cladogram below, the English names are those introduced in 1997.[46] The scientific names are those introduced in 2013.[47]