About a month ago, as I was driving to Troy, Alabama, for a Rotary meeting, I happened to catch the tail end of the program Living on Earth on Troy public radio station WTSU. The segment I heard was called “The Hidden Sounds of Bird Song,” and in it renowned bird scientist Donald Kroodsma was being interviewed by program producer Laurie Sanders about his experiments with slowing down recorded bird songs to hear otherwise undetectable subtleties.
This was pretty interesting stuff, but the most arresting comment was this: “Depending on the species, a songbird may have just a few songs in its repertoire or it might have hundreds. A brown thrasher has more than 2,000.” One online source claims that the thrasher has “up to 3,000 catalogued sounds.” Whatever the number, the thrasher is generally acknowledged to have the largest song repertoire of all North American birds.
The Outdoor Alabama site says:
The brown thrasher belongs to the order Passeriformes, birds that have feet well adapted for perching, with three toes in front and one long toe behind. It is in the family Mimidae, which includes thrashers and mockingbirds. Members of this bird family sing loudly from conspicuous perches, imitating other bird songs. While mockingbirds repeat phrases many times, the brown thrasher usually emits the song twice.
Another site says, “The brown thrasher is known to be one of the best and most spectacular singers, with the largest repertoire of songs of all North American birds. It is also a very shy bird so that the chance of people actually spotting the bird is smaller than that of hearing the bird sing.”
I would tend to disagree with both statements.
I first became aware of brown thrashers when I heard them outside an open window, living up to their names by thrashing about in the dry leaves and underbrush. And I certainly have no difficulty spotting them; they are quite frequent visitors to our yards and gardens. But unlike their high-wire-artist cousins, the mockingbirds, which seem to love to perch on power lines and pine branches for their impressive concerts, I rarely see thrashers very far above the ground.
And I have never knowingly heard them sing.
Presumably there are two reasons for this: One is that I wouldn’t know it was a thrasher singing unless I could see it doing so. And since, unlike the mockingbird, it isn’t taking pains to be conspicuous doing it, I’m less likely to see it. The other is that, with such a large repertoire of songs, there is not any one specific call that I could easily identify. Mourning doves, for example, are dead easy. And other bird calls are equally distinctive even if I don’t know which birds to associate them with. But I would have to have a much better ear than I have for the sound of a thrasher’s voice to be able to identify it when it might well be singing a different song every time I hear it.
So I remain tantalized by the idea of these seemingly mute and retiring birds being such “spectacular singers,” and this causes me to give them a second look every time I see them, just to see if their lips are moving.
WalkThoughts 