Allen’s Hummingbird is a small species of hummingbird that only grows up to 3 to 3.5 inches in length upon reaching the age of maturity.
There are two recognized subspecies of Allen’s Hummingbirds, which only have a slight difference in physical appearance. The Sedentarius of the southernmost regions of California are non-migratory. The smaller one, Sasin, spends the winter in Mexico.
The Allen’s Hummingbird was first noticed by Charles Andrew Allen, who eventually described the bird to American scientists. The bird was later on named after him.
Compared with other Northern American birds, the Allen’s Hummingbird is considered as an early migrant to the US. The Allen’s that are heading towards the North may leave on spring migration as early as December and arrive on their summer breeding grounds as early as January. Adult males may start heading towards the south in mid-May and arrive on winter grounds as early as August.
Both sexes of Allen’s Hummingbirds have a body length of about 3.5 inches. Their wingspan reaches up to 4.3 inches from tip to tip. Their weight ranges from 2 to 4 grams.
The Allen’s Hummingbird closely resembles the Rufous Hummingbird. It has a small and compact build with an extensive rusty look in most of its plumages. Apparently, the male and female Allen’s hummingbirds have different physical features.
The adult male Allen’s Hummingbird has an iridescent red throat, which has elongated feathers that are slightly projecting to the sides. The color of the top of the bird’s head and back are metallic bronze and bronze green. The sides of the face and chest, as well as the bird’s flanks are plain cinnamon-rufous. It has a white chest. There is a white spot that can be found behind the bird’s black eye.
The male Allen’s tail feathers are pointed and are colored orange, although its tips are darkish in color. Its outermost tail feather is noticeably narrow. Its belly and under tail coverts are described as ‘buffy’. Its wings, along with the legs and feet, are often described as dusky.
On the other hand, the female Allen’s Hummingbird has a metallic bronze-green back and a whitish chin, throat, and chest. The center of the bird’s throat has patches of red feathers that are of different sizes. Similar to the male, the sides and flanks of the female are also cinnamon-rufous.
It has dusky wings. The three pairs of outermost tail feathers show an interesting color variation. The base color of the feathers is orange, the middle is black, and the tip is white. The middle pair of the feathers in the tail is bronze-green in color, the tips are dusky, the edges are orange and the base is green. The next pair has a rufous base, bronze-green middle, and black tips. The bird’s undertail coverts are pale cinnamon.
Most of the juvenile Allen’s Hummingbirds look like the adult female, although they exhibit less spotting on the throat and less rufous on their flanks. Also, younger juveniles are rustier in the base of the tail.
Habitat, Food, Nesting and Behavior
The range of the Allen’s Hummingbird’s breeding location runs along a narrow strip of coastal California and southern Oregon.
They breed in moist coastal areas, scrub, chaparral, and forests. During winter, they would seek shelter from forest edges and scrub clearings with flowers. They feed on flower nectar, small insects, and tree sap.
Aside from differences in physical characteristics, breeding male and female Allen’s hummingbirds also differ in habitat choice. The male Allen’s sets up a habitat that overseas open areas of coastal scrub vegetation or riparian shrubs, as these spaces allow him to conspicuously perch on exposed leafless branches. On the other hand, the female Allen’s Hummingbird selects nest locations in more densely vegetated areas and forests.
The nest of Allen’s Hummingbirds closely resembles an open cup of plant down with an outer layer of grass or leaves. The outside is usually covered with lichens, moss, or pieces of bark that are held together by a spider web. The nest is usually placed in a shrub or a small twig or branch of a tree. The female would then lay two white eggs, which she incubates for about 15 to 17 days.
The baby Allen’s Hummingbirds are helpless upon birth, with black skin and some down on back. However, after three weeks from hatching, the young birds already leave the nest. The mother bird continues to take care of the baby birds for several more weeks until they are left to fend for themselves.
The Allen’s Hummingbirds hover at flowers and sap wells, especially because their high rate of metabolism requires them to feed frequently. They also love catching flying insects, or plucking them out from leaves. These animal food serves as their sources of protein.
The Allen’s Hummingbird has a ‘Least Concern’ status under the International Union for Conservation of Nature and Natural Resources (IUCN). Its populations are reported to be declining, which explains why the species was included in the 2014 State of the Birds Watch List. This means that the Allen’s Hummingbird belong to the animal species most in danger of extinction if no significant conservation action will be undertaken by different conservation groups and authorities.