Credit: Karney, Lee / USFWS

The Allen's Hummingbird is a small bird, with mature adults reaching only 3 to 3½ inches (75 to 90 mm) in length.
The male Allen's has a green back and forehead, with rust-colored rufous flanks, rump, and tail.
The male's throat is also an iridescent orange-red.
The female and immature Allen's Hummingbirds are similarly colored, but lack the iridescent throat patch,
instead having a series of speckles on their throat.
Females are mostly green, featuring rufous colors only on the tail, which also has white tips.


Credit: Karney, Lee / USFWS

The Allen's Hummingbird is common only in the brushy woods, gardens, and meadows of coastal California
from Santa Barbara north, and a minuscule portion of lower Oregon.
The nominate race of Allen's Hummingbird S.s. sasin is migratory,
and winters along the Pacific coast of central Mexico.

The courtship flight of the male Allen's Hummingbird is a frantic back and forth flight arc of about 25 feet (10 m)
similar to the motion of a swinging pendulum, followed by a high-speed dive from about 100 feet (30 m).
The male is also highly aggressive and territorial. Hot-tempered despite its diminutive stature, a male Allen's
Hummingbird will chase any other males from its territory, as well as any other hummingbird species, and they
have even been known to attack and rout predatory birds several times larger than themselves
such as kestrels and hawks.
Text below two above pictures from Wikipedia


Credit: Karney, Lee / USFWS
http://www.mbr-pwrc.usgs.gov/id/framlst/i4340id.html

The hummingbird’s hovering and darting movements impose a huge metabolic burden.One crucial element of the bird’s
nectar-collection system -- its tongue. The tongue is about 2 cm long, twice as long as the beak.
When dipped into nectar it spontaneously wraps into a cylindrical straw shape, which then acts as a siphon.
The capillary rise of nectar up the column is quick, allowing the bird to fill its tongue up to 20 times per second.
After each dip the nectar is scraped free and swallowed.