On a bright spring morning, a variety of calls and song will drift from the oaks. They include the burry call of a western wood pewee, the hurried, rich tones of a lazuli bunting, the whinny of a downy woodpecker and the mewing of a wood duck.
Wood duck!? A wood duck in an oak tree?
Well, it's possible. They do roost in trees and nest in tree cavities. But then you'll realize that all these sounds are coming from a single tree, and the sounds seem to be a part of a larger chorus of chaotic sounds.
Maybe a starling is trying to impress friends and potential mates. Starlings are known for mimicry. But no, not this time. Possibly it's a mockingbird. A few individuals call the Rogue Valley home, and mockingbirds are talented mimics that put starlings to shame. No, it's not a mockingbird either.
This performer with the astonishing range is a bird that gets little respect. Even its name suggests unimportance — the lesser goldfinch. Two kinds of goldfinches live in the valley, the American and lesser — three if you include the closely related pine siskin.
The male American goldfinch in breeding plumage is a dazzling yellow with a black cap and wings. It is so impressive that Washington has chosen it to represent the state. American goldfinches are common in the valley at times, usually in agricultural lands.
The tiny lesser goldfinch is not as brightly-colored. Males have a black cap and bright yellow belly, but the back is a drab green. Females have no bright colors at all, just a small patch of white in the wings.
Lesser goldfinches are not so common in the hedgerows and pastures, but they are one of the most common birds among the oaks and on chaparral-covered hillsides. They outnumber the American goldfinch and pine siskin by far in my yard.
American goldfinches and pine siskins sing pleasing if not terribly impressive songs, but I have never heard them mimic other birds. This is curious. Why should one species mimic while close relatives do not?
In other species, the male with the most elaborate song gets the girl. Embellishment comes with age. Cowbirds, starlings and marsh wrens all continue to add to their song or add new songs with each succeeding year. A male with a complex song or large repertoire is an older male that has successfully negotiated the hazards of life and is, therefore, a male of high quality and a worthy mate. Borrowing sounds from other species is one way of adding to a song.
Do lesser goldfinches live longer than American goldfinches or pine siskins, giving them a greater reason to refine their song? That is a question for an enterprising researcher some day.
While waiting for the answer, I will continue to enjoy the small flock of lesser goldfinches with their modest splash of color at my sock feeder filled with nyjer seed. As I listen to the song of a contented male, I add still one more species to my growing list of birds mimicked by lesser goldfinches. This time it is the song of the oak titmouse.
Stewart Janes is a biology professor at Southern Oregon University. He can be reached at firstname.lastname@example.org.