Thursday, April 24, 2014

Allen's Hummingbird

Allen's Hummingbird
Allen's Hummingbird. March 30, 2014. San Elijo Lagoon, California. Greg Gillson.
Allen's and Rufous Hummingbirds are very similar. For the green females, the distinction between the two species is the width of certain tail feathers. For males, the Rufous has a rusty back, while the Allen's back is green. There is some overlap, with a few Rufous having some green feathers on the upper back. In this case, again, there are differences in the widths of tail feathers. The males' courtship display flights are different, and presumably the females can tell them apart.

Allen's Hummingbirds breed along a narrow coastal strip from southern California to extreme southern Oregon. In fact, Allen's Hummingbirds barely make it 30 miles into southern Oregon. From this point northward to Alaska and inland Rufous Hummingbirds breed.

There are two subspecies of Allen's Hummingbirds. One is sedentary (non-migratory), found on the Channel Islands off Los Angeles, and only on the mainland in recent years. All the other Allen's Hummingbirds migrate to a very small area to winter in southern Mexico in the states of Mexico, Morelos, and Puebla.

I found Allen's Hummingbirds here in San Diego County in January, thus one of the resident form, now expanding their range farther from Los Angeles. Many other Allen's, presumably of the migrant race, arrived in March. And I did see one Rufous Hummingbird migrating through in March, too.