Hummingbirds
Selasphorus sasin
The Allen's Hummingbird is a small, compact hummingbird known for its vibrant coppery-orange and green plumage. Males display a brilliant reddish-orange throat, while females and immatures are bronze-green with rufous flanks. This species is a remarkably early migrant compared to most North American birds, with some individuals beginning their northbound journey as early as December.
Typical adult measurements.
Individuals and populations vary.
01 / The telltale details
Start with shape and behavior. Then look for the smaller details.
Iridescent reddish-orange throat (gorget), bronze-green back, coppery-orange tail, eye patch, and flanks.
Bronze-green upperparts, paler coppery sides, and a white throat with variable bronze spotting, sometimes with a small central reddish-orange patch.
Similar to adult females, with bronze-green upperparts and rufous on the flanks, but typically with less throat spotting.
When perched, the tail extends past the wings, and the outermost tail feather is notably narrower than the others.
02 / A place in the world
Allen's Hummingbirds breed in moist coastal areas, including scrub, chaparral, and forests. They can also be found in open oak woods, streamside groves, and well-wooded suburban areas and city parks.
The breeding range is a narrow strip along coastal Oregon and California. A migratory subspecies winters in central Mexico, while a non-migratory subspecies resides year-round on California's Channel Islands and has expanded its range to the adjacent southern California mainland.
One subspecies (S. s. sasin) is migratory, traveling between coastal Oregon/California and central Mexico. Another subspecies (S. s. sedentarius) is non-migratory, residing year-round in southern California, including the Channel Islands. Males often migrate earlier than females and juveniles.
03 / Listen a little closer
Both sexes emit high-pitched "tick" calls while feeding and sharp chattering sounds during interactions or territorial defense. Male courtship displays include buzzy humming and a sharp, metallic tail squeal.
04 / The life behind the feathers
Their primary food source is nectar, which they obtain by probing tubular flowers. They also consume small insects, caught both in mid-air and gleaned from plants.
Allen's Hummingbirds feed by inserting their long bills into flowers to access nectar. They also actively catch small insects, either by hawking them in flight or by picking them off vegetation.
Females construct open cup nests from plant down, reinforced with grass or leaves, and camouflaged with lichens, moss, or bark held together with spider silk. Nests are typically placed in shrubs or on small tree branches.
Males are highly territorial, aggressively defending their breeding grounds from other hummingbirds and even larger birds. During courtship, males perform elaborate aerial displays, including pendulous arcs and high dives.
One more reason to pay attention
The scientific name *Selasphorus sasin* has an interesting history; the species was initially named *Selasphorus alleni* but an earlier description took precedence.
Allen's Hummingbirds are important pollinators for various plants, including some federally endangered species.
The oldest recorded Allen's Hummingbird lived to be at least 5 years and 11 months old.
05 / An eye for the difference
Adult male Allen's typically has a green back, while adult male Rufous usually has an all-rufous back. Females and immatures are nearly indistinguishable in the field.
Anna's Hummingbirds are generally larger and males have an iridescent rose-pink gorget and crown, contrasting with the Allen's reddish-orange gorget and green crown.
AI-assisted species research. Prepared September 2026. Details can vary across regions and populations.