Prolonged hovering and flying backwards are unique to hummingbirds. This amazing flight ability requires huge amount of food (caloric input) in order to sustain the flights. This is why hummingbirds have to constantly be feeding during the day and go torpid at night. If a human used energy at the rate that a hummingbird does, he/she would have to consume about four hundred pounds of potatoes and a thousand quarter-pound hamburgers every day.
(Arizona-Sonora Desert Museum 1998)
Perception Channels: visual ; tactile ; acoustic ; chemical
US Federal List: no special status
CITES: appendix ii
IUCN Red List of Threatened Species: least concern
There is neither positive nor negative economic importance for the Allen's Hummingbird, but they do help in the pollination of flowers.
Allen's Hummingbird has a long narrow bill and long tongue. This feature allows it to obtain nectar from flowers. They feed every ten to fifteen minutes and visit approximately 1,000 flowers a day. Nectar is their main source of energy, but they also obtain protein from small insects like flies, ants, small beetles, tiny wasps, and other small insects. Because the hovering flight used by these birds to gather nectar requires phenomenal amounts of energy, the Allen's hummingbird has to consume over twice its weight of nectar each day.
(Cassidy 1990, Arizona-Sonora Desert Museum 1998, Stokes 1989)
Allen's Hummingbird, Selasphorus sasin, is a migratory bird which summers along the pacific coast of the United States from Oregon to southern California. During the winter it migrates to northwestern Mexico.
(Peterson 1990, Terres 1980)
Biogeographic Regions: nearctic (Native )
The Allen's Hummingbirds can be found in bushy woods, gardens, flower filled mountain meadows, and parks.
(Cassidy 1990, Stokes 1996)
Terrestrial Biomes: savanna or grassland ; forest
Average lifespan
Status: wild: 48 months.
Allen's Hummingbirds are among the smallest birds, they are only 7.5 to 9 cm (3-3.5 in.) long and typically weigh a little over 3 grams (0.1 oz.). In appearance they resemble their closest relative, the Rufous Hummingbird. A male Allen's hummingbird has a fiery red-orange throat, white collar, and metallic green on its back and cap. The female's upper body is green. The tail and sides are orange-brown and the throat and central belly is white with iridescent dots on its throat.
(Stokes 1996, Farrand 1988, Terres 1980)
Average mass: 3 g.
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 3 g.
Average basal metabolic rate: 0.06853 W.
Female Allen's hummingbirds usually start building their nest before they mate. After mating the female alone has to finish the half built nest. She uses moss, bits of vegetation, spider webs, bark flakes, and pine needles to finish the cup-shaped nest. This nest is only about 4 cm (1.5 in.) from top to bottom and 4-5 cm (1.5-2 in.) in diameter. She lays only two eggs, which are about 1 cm (1/2 in.).
The female alone incubates the eggs for about 16 to 22 days. Once the baby hummingbirds are hatched, the mother fearlessly protects her young. She alone has the duty to feed them until they are ready to leave the nest. She feeds them by inserting her bill into the baby's mouth and regurgitating food from her crop. Chicks usually fledge (leave the nest) in about 22 days and are immediately independant of their mother.(Baicich 1997, Ehrlich 1988, Terres 1980, Stokes 1989)
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average time to hatching: 16 days.
Average eggs per season: 2.
Allen's hummingbird (Selasphorus sasin) is a species of hummingbird that breeds in the western United States. It is one of seven species in the genus Selasphorus.
Allen's hummingbird is a small bird, with mature adults reaching only 3 to 3.5 in (76 to 89 mm) in length. The male has a green back and forehead, with rust-colored (rufous) flanks, rump, and tail. The male's throat is an iridescent orange-red. The female and immature Allen's hummingbirds are similarly colored, but lack the iridescent throat patch, instead having a series of speckles on their throats. Females are mostly green, featuring rufous color only on the tail, which also has white tips. Immature Allen's hummingbirds are so similar to the female rufous hummingbird, the two are almost indistinguishable in the field. The lack of a notch in the second rectrix (R2) is considered an important field mark to distinguish the adult male Allen's hummingbird from rufous hummingbird, particularly the hard to distinguish green-backed variety.[3] Both species' breeding seasons and ranges are common factors used to differentiate between the two species in a particular geographical area.
Allen's hummingbird was formally described by the French naturalist René Lesson in 1829 and given the binomial name Ornismya sasin.[4] The specific epithet is a Wakashan or Nootka Native American name for a hummingbird.[5] The type locality is San Francisco.[6] Allen's hummingbird is now placed in the genus Selasphorus that was introduced by William Swainson in 1832.[7][8] The common name commemorates Charles Andrew Allen, an American collector and taxidermist who identified the bird in 1879 in Nicasio, California.[9]
Two subspecies are recognised:[8]
A hybrid between this species and Anna's hummingbird has been described as Floresi's hummingbird, "Selasphorus" floresii.[10][11]
Allen's hummingbird is common only in the brushy woods, gardens, and meadows of coastal California from Santa Barbara north, and southern coastal Oregon. The nominate race, S. s. sasin, is migratory, and in southern central Mexico. A second, S. s. sedentarius, is a permanent resident on the Channel Islands off southern California.[12] This population colonized the Palos Verdes Peninsula of Los Angeles County in the 1960s and has since spread over much of Los Angeles and Orange Counties, south through San Diego County, and east to the western end of Riverside County.
The courtship flight of male Allen's hummingbirds is a frantic back-and-forth flight arc of about 25 ft (7.6 m) similar to the motion of a swinging pendulum, followed by a high-speed dive from about 100 ft (30 m) during which tail feathers emit a characteristic sharp flutter to further attract attention of the female.[13] Aggressive and territorial, male Allen's hummingbirds will chase any other males from their territory, as well as any other hummingbird species, and have even been known to attack and rout predatory birds several times larger than themselves, such as kestrels and hawks.
Allen's hummingbird constructs its nest out of plant fibers, down, and weed stems, coating the nest with lichens and spider webs to give it structure. The nest is placed above ground on a tree branch or the stalk or stem of a plant. The female lays one or two white eggs, which she incubates for 15 to 17 days. The young leave the nest about three weeks after hatching. The mother continues to feed the fledglings for several more weeks, then the young are left to fend for themselves.
Like all hummingbirds, Allen's hummingbird's high rate of metabolism requires it to feed frequently. It drinks nectar from flowers and eats any small insects in flight or on flower blossoms, providing needed protein.
Feeding
Adult female tending a nest
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Juvenile male or female
In art
Allen's hummingbird (Selasphorus sasin) is a species of hummingbird that breeds in the western United States. It is one of seven species in the genus Selasphorus.
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