Allen's Hummingbird

The Allen's hummingbird (Selasphorus sasin) is a diminutive avian jewel, with mature adults measuring a mere 3 to 3.5 inches in length and tipping the scales at approximately 2 to 4 grams. The male is resplendent with a green back and forehead, complemented by rust-colored flanks, rump, and tail. His throat shimmers with an iridescent orange-red hue. The female and immature Allen's hummingbirds share a similar color palette but are distinguished by the absence of the iridescent throat patch, displaying instead a series of speckles. Females are predominantly green with rufous only on the tail, which is also tipped with white. The immature birds are nearly indistinguishable from the female rufous hummingbird in the field.

Identification Tips

To distinguish the adult male Allen's hummingbird from its close relative, the rufous hummingbird, one must look for the absence of a notch in the second rectrix (R2), particularly in the green-backed variety. The timing of breeding seasons and geographical ranges are also key factors in differentiating between the two species.

Habitat

Allen's hummingbirds are commonly found in the brushy woods, gardens, and meadows of coastal California and southern coastal Oregon.

Distribution

The migratory subspecies, S. s. sasin, breeds in southern Oregon and California, wintering in south-central Mexico. The S. s. sedentarius subspecies is a permanent resident on the Channel Islands off southern California and has expanded its range to parts of Los Angeles, Orange, and Riverside Counties.

Behaviour

The male Allen's hummingbird performs a courtship display that is a frenetic back-and-forth arc, akin to a pendulum, followed by a high-speed dive from great heights, with tail feathers creating a distinctive flutter. These birds are fiercely territorial; males will chase away competitors and even larger predatory birds. After mating, the male does not assist in rearing the young.

Song & Calls

Both male and female Allen's hummingbirds communicate with high-pitched vocalizations in social interactions, whether familial or territorial.

Breeding

Females prefer to nest in forests with large trees, using plant fibers, down, and weed stems to construct their nests, which are camouflaged with lichens and spider webs. The nest-building process takes about a week. Females lay one or two white eggs and incubate them for 15 to 17 days. The fledglings leave the nest after about three weeks but are fed by the mother for several more weeks before becoming independent.

Diet and Feeding

With a high metabolic rate, Allen's hummingbirds feed frequently on nectar and small insects such as flies, ants, beetles, spiders, and wasps. They play a crucial role in pollination, supporting the survival of various plant species, including the endangered Western Lily.

Conservation status

Despite being classified as Least Concern by the IUCN, the Allen's hummingbird has experienced a significant population decline, losing about 83% of its population in the last fifty years. However, they have shown adaptability by utilizing invasive plants and bird feeders in their changing habitats.