Allen's Hummingbird (Selasphorus sasin): Complete Guide to California's Brilliant Early Arrival

Allen's Hummingbird is a small, compact hummingbird with vivid rufous coloration and one of the fastest wingbeat rates recorded for any North American species --- up to 55 beats per second during displays. The defining field challenge for this species is separation from the nearly identical Rufous Hummingbird, and the key to that separation lies almost entirely in back color.

Male Appearance

The adult male Allen's Hummingbird is a richly colored bird with a distinctive green back and crown --- this is the single most important field mark separating him from the male Rufous Hummingbird, whose back is entirely rufous. The flanks, rump, and tail are rich rufous-orange. The gorget is a spectacular blazing orange-red (sometimes described as flame or copper-orange), iridescent and capable of appearing black in poor light. The tail is moderately forked. The overall combination --- green back, rufous body and tail, brilliant gorget --- makes adult males identifiable in good views, though the distinction from Rufous requires seeing the back clearly.

Female Appearance

Female Allen's Hummingbirds are essentially identical to female Rufous Hummingbirds in the field. Both have green backs, rufous flanks, white underparts, and spotted or streaked throats with occasional orange-red gorget feathers. The tail pattern --- rufous at the base, black subterminal band, white tips on outer feathers --- is identical or nearly so. Even in hand, females of the two species are separated only by tail feather shape (the outermost rectrix of Allen's females is slightly narrower and more pointed), a feature requiring close examination. Range and season provide the most practical separation: in coastal California from January through June, an unidentified female in this group is almost certainly Allen's.

Juvenile Appearance

Juvenile Allen's are similar to females. Young males begin developing orange-red gorget feathers during their first summer and fall. Juveniles of both sexes show fine buffy feather edges on the upperparts. Juvenile males can be particularly challenging --- some show a mix of green and rufous on the back that overlaps with both Allen's and Rufous patterns before the full adult plumage is acquired.

Similar Species & How to Tell Them Apart

Rufous Hummingbird (Selasphorus rufus): The primary confusion species. Key difference: Adult male Rufous has an entirely rufous back; adult male Allen's has a green back. Females are essentially inseparable in the field --- rely on range and timing. In coastal California before May, assume Allen's. After June, incoming Rufous migrants must be considered.

Broad-Tailed Hummingbird (Selasphorus platycercus): Larger; male has a rose-magenta gorget and green back but lacks rufous flanks. Ranges overlap minimally.

Anna's Hummingbird (Calypte anna): Year-round California resident; larger with a rose-red crown and gorget on males. Females are larger and grayer. The most frequent co-occurring species with Allen's throughout California.

Calliope Hummingbird (Selasphorus calliope): Noticeably smaller with a streaked gorget on males. Female Calliope is smaller with paler flanks than female Allen's.

The migratory subspecies of Allen's Hummingbird follows one of the earliest and most compressed migration schedules of any North American hummingbird. Adult males begin arriving on California coastal breeding territories in late December through January --- the earliest returning hummingbird in the continental U.S. This early arrival gives males time to establish territories before females arrive 2--4 weeks later, allowing successful pairs to potentially raise multiple broods during a long nesting season.

Spring migration is essentially a northward progression along the California and southern Oregon coast, with males leading and females following. After breeding, adults begin departing coastal California by June and July --- extremely early for a "summer" bird. They migrate south and inland, moving through interior California, Nevada, and Arizona en route to wintering grounds in western Mexico (primarily Jalisco and Michoacán).

This creates an interesting identification situation: by July and August, Rufous Hummingbirds are migrating south through California in large numbers, while some Allen's are also present. The two species are effectively sympatric during this window, making late-summer identification particularly challenging. By September, most migratory Allen's have departed; the Rufous passage continues into October and November.

The sedentary S. s. sedentarius does not migrate and remains in the greater Los Angeles area year-round.

Allen's Hummingbirds are bold, territorial, and frequent feeder visitors --- especially in California coastal gardens where sedentary populations have made year-round feeding possible and valuable.

Year-round availability: In Southern California and the Bay Area, keep feeders available year-round. Sedentary Allen's in greater LA have no migration and depend on garden resources through winter. Migratory Allen's arrive in coastal California as early as January.

Multiple feeders: Allen's males are highly territorial. Placing 3--4 feeders around the garden --- some visible from the dominant male's favorite perch, some hidden from his view --- allows subordinate birds, females, and juveniles to feed without constant harassment.

Feeder height and placement: Mount feeders at 5--6 feet, near cover (shrubs or trees the birds can retreat to) but with clear flight paths. Allen's Hummingbirds prefer open approaches.

Cleanliness: In Southern California's warm winter and spring temperatures, nectar can ferment quickly. Change nectar every 2--3 days during warmer months (above 70°F), every 4--5 days in cool coastal conditions. Rinse feeders thoroughly; black mold in feeders is harmful and must be scrubbed out with a brush before refilling.

Nectar formula: Always use plain white cane sugar and water, 1:4 ratio. Never honey (dangerous fungal risk), artificial sweeteners (zero calories), or red dye (unnecessary and potentially harmful).

Explore the NectarBloom Hummingbird Trail for detailed feeder recommendations by California region and season.

Allen's Hummingbird nests earlier than almost any other North American hummingbird --- a direct consequence of the male's January arrival and the mild, relatively predictable winters of coastal California. Females begin nest construction as early as January in Southern California, with nesting activity peaking February through May.

The nest is a compact, deep cup constructed from plant fibers, thistledown, moss, and spider silk --- the spider silk being structurally critical, as it allows the nest to stretch as chicks grow and holds the wall structure together over multiple weeks of use. The exterior is decorated with lichen, plant fragments, and bark bits for camouflage. Nests are typically placed in dense shrubs, eucalyptus trees, or tangles of ivy or climbing roses --- sites that combine structural support with visual concealment. Coastal chaparral gardens offer abundant suitable nest sites, which may explain why the sedentary subspecies has adapted so successfully to urban and suburban Southern California.

Two white eggs are laid. Incubation lasts approximately 17--22 days. Chicks fledge at 22--25 days. Because of the early start and long mild-season window, females regularly raise two broods and occasionally attempt a third. Males provide no parental care --- they continue territorial defense at feeding sites throughout the breeding season.

Female Allen's show strong nest site fidelity, often returning to the same garden, same shrub, and even the same branch in successive years.

Allen's Hummingbird is classified as Least Concern by the IUCN Red List. However, the conservation picture is nuanced. The migratory subspecies (S. s. sasin) depends on the narrow coastal scrub and chaparral habitats of coastal California and southern Oregon --- a zone under sustained pressure from urban development, invasive plants, and altered fire regimes. Breeding Bird Survey trends for this subspecies show some evidence of decline in portions of its range, though data from coastal areas are sparse due to terrain challenges.

The sedentary subspecies (S. s. sedentarius) is, if anything, expanding --- its colonization of the Los Angeles metropolitan area represents a rare case of a bird species benefiting from urbanization. The trade-offs include dependency on garden plants and feeders (non-native habitat elements) and exposure to window strikes, outdoor cats, and pesticide-related insect declines.

Habitat conservation in coastal California --- particularly protection of native coastal scrub and chaparral --- is the most meaningful systemic intervention for the migratory subspecies. For backyard birders, maintaining clean feeders with appropriate nectar, planting native California species, reducing pesticide use, and keeping cats indoors are direct and practical contributions.