Hummingbird

Hummingbird Temporal range: Rupelian 30–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N
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 Linnaeus, 1758
Subfamilies
Subfamiles: †Eurotrochilus Florisuginae Phaethornithinae Polytminae Lesbiinae Patagoninae Trochilinae (For an alphabetic species list, see List of hummingbird species)

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]