Sunday, November 27, 2011

Learning about birds... at your feeder

Spotted TowheeMale Spotted Towhee, Beaverton, Oregon, 27 November 2011 by Greg Gillson.


For improving one's birding skills, Kenn Kaufman (Kaufman Field Guide to Advanced Birding) recommends a bird feeder as a learning tool. Even a common species observed closely over time can teach about age and gender differences, molt and plumages, hybridization, and individual or population variation. Learning how to observe these items on common birds will let us more quickly and accurately identify rare birds--a source of joy and excitement for many birders.

Earlier this year I learned something very interesting by observing the birds at my feeder. Although perhaps not surprising, I observed a subspecies of Spotted Towhee not previously documented in western Oregon. I wrote about it here: (Barely spotted towhee gets super spotted visitor).

Now that I am attune to this particular ID challenge, I was ready today when I again spotted an unusual towhee visitor to my feeder. The top photo shows a resident male Spotted Towhee, typical of those found in western Washington and Oregon, the so called Oregon Towhee (Pipilo maculatus oreganus).

The ID of the above bird is straightforward. Compared to all other populations it has fewer spots on its scapulars and wings. The rufous sides are darker than other populations. Finally, the spots on the undertail are very small, perhaps restricted to only the outermost tail feathers of each side of the tail.

Compare the bird above with the bird below, seen about 15 minutes apart in the same tree--photographed through my very dirty window!

Spotted TowheeMale Spotted Towhee, Beaverton, Oregon, 27 November 2011 by Greg Gillson.


This bird is paler orange on the side and undertail coverts. It has more and larger spots on the scapulars and wings. Obviously, the white tail spots take up more than half the tail and are spread out on at least three of the outer tail feathers.

This bird matches one of the "Interior" forms of Spotted Towhee. The new National Geographic Field Guide to the Birds of North America, Sixth Edition has range maps showing the various subspecies of Spotted Towhees.

Without a specimen to measure fine variations, it is only speculation as to which exact subspecies may be represented. And due to individual variation, even a specimen may not be unequivocally decisive in this matter. However, it is sufficient to separate the Pacific form (to which the Oregon Towhee belongs) from the Interior form to report this to eBird. In fact, birders in Washington are noting the winter influx of the Interior form of Spotted Towhees into western Washington where, as in western Oregon, they were previously undocumented.

These new winter distribution records are found, not from scientists studying specimens or conducting field research, but by amateur bird watchers at their backyard feeders!

What's in your feeder?