The Allen's Hummingbird, Selasphorus sasin, is a species of hummingbird, a
family of small passerine birds.
The Allen's Hummingbird is a small bird, with mature adults reaching only 3 to 3½ inches in length. The male Allen's has a
green back and forehead, with rust-colored rufous flanks, rump, and tail. The male's throat is also 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 throat. Females are mostly green, featuring rufous colors only on the tail, which also has white tips. The
female and immature Allen's Hummingbirds are so similar to the female Rufous
Hummingbird that the two are almost indistinguishable in the field. Both species' breeding seasons and ranges are common
factors used to differentiate between the two species in a particular geographical area.
The Allen's Hummingbird is common only in the brushy woods, gardens, and meadows of coastal California from Santa Barbara north, and a minuscule portion of lower Oregon. The nominate race of Allen's Hummingbird, S.s. sasin is migratory, and winters along the Pacific coast of central Mexico. A
second race S.s. sedentarius is a permanent resident on the Channel Islands off southern California. 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.
The courtship flight of the male Allen's Hummingbird is a frantic back and forth flight arc of about 25 feet similar to the
motion of a swinging pendulum, followed by a high-speed dive from about 100 feet. The male is also highly aggressive and
territorial. Hot-tempered despite its diminutive stature, a male Allen's Hummingbird will chase any other males from its
territory, as well as any other hummingbird species, and they have even been known to attack and rout predatory birds several
times larger than themselves such as kestrels and hawks.
The Allen's Hummingbird constructs its nest out of plant fibers, down, and weed stems, coating the nest with lichens 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 two white eggs, which she will incubate for 15 to 17 days. The young will leave the nest about three weeks after
hatching. The mother will continue to feed the fledglings for several more weeks, then the young are left to fend for
themselves.
Like all hummingbirds, the Allen's Hummingbird's high rate of metabolism requires it to feed frequently, about every 10 to 15
minutes. The Allen's Hummingbird drinks nectar from flowers, as well as eating any small insects
it finds crawling around the flower blossom, which provide it with needed protein.
A hybrid between this species and Anna's
Hummingbird has been described as Floresi's Hummingbird, "Selasphorus" floresii (Ridgway, 1909; Taylor, 1909).
References
- BirdLife International (2004). Selasphorus sasin. 2006 IUCN Red List of Threatened
Species. IUCN 2006. Retrieved on 09 May 2006. Database entry
includes justification for why this species is of least concern
- Ridgway, Robert (1909): Hybridism and Generic Characters in the Trochilidae. Auk, 26(4): 440-442. PDF fulltext
- Taylor, Walter P. (1909): An instance of hybridization in hummingbirds, with remarks on the weight of generic
characters in the Trochilidae. Auk, 26(3): 291-293. PDF fulltext
External links
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