Allen's Hummingbird, Selasphorus sasin


Allen's Hummingbird
The back and crown on male Allen's Hummingbirds are green, as shown above (also note the ant in
his bill!) The same areas on the similar male
Rufous Hummingbird are rufous, sometimes with a few
green feathers. (A very few Rufous males show extensive green backs; an all- or mostly-rufous back is
diagnostic of Rufous.)
 


Allen's Hummingbird
Female Allen's and Rufous Hummingbirds generally can't be distinguished in the field by structure or plumage, except in the rare case where (as in the picture above) the tail feathers are visible. The Allen's second tail feathers out from the center (R2) are lanceolate (spear-shaped) as can be seen especially clearly on this bird's left side in this picture. The same feathers on the Rufous are notched on one side. The R2 distinction holds for both sexes; see the male Allen's below showing a lanceolate right R2. Another way of distinguishing females is that in coastal California, nesting females are invariably Allen's; Rufous are seen there only in migration.


Allen's Hummingbird
Above, a male Allen's showing tail feathers; the outer two, R4 and 5, overlapping on the bird's right, are narrower
in Allen's of both sexes than in Rufous. Below, another male Allen's with tail feathers spread, showing the lanceolate
R2 on both sides, and on the bird's left, R4 and 5 adjoining but visibly narrower than the corresponding feathers in
Rufous. 



Allen's Hummingbird

Allen's Hummingbird
The pictures on this page were mostly taken at the UC Santa Cruz Arboretum, where Ruby-cluster bushes in the Australia section attract Allen's Hummingbirds, and make this probably the best place to observe and photograph this species. The males show off the distinctive Allen's display flight -- a series of short back-and-forth horizontal shuttles, followed by a steep ascent and then a rapid dive with a short turn upward at the end, accompanied by a wing-generated whistle.  


Allen's Hummingbird

Allen's Hummingbird

Allen's Hummingbird
The hummingbird's remarkable tongue can be as long as its head; it allows the bird to gather nectar by a combination of scooping and sucking, first revealed in 2012 by high-speed video of a hummer's drinking action.