The Music of Many Pine Warblers – Not All Songs Alike
The simple, musical trill of a Pine Warbler may be much more than it seems.
With their sunny yellow throat and breast, Pine Warblers bring a welcome wash of color to the drab winter landscape. And now they’re bringing warm, spring-like music to the bare woods, too, in songs with a subtle and somewhat surprising variety of slightly different sounds.
Because Pine Warblers are fairly common here year-round, it’s easy to hear their songs as just a sort of background music, all sounding pretty much alike. But this year we’ve had an unusually large number in our neighborhood, and I can often hear two or three singing in different directions at the same time, and even more further down the road – so I’ve begun to notice and to listen more closely for their different voices and different expressions.
Usually described as a simple, loose, musical trill, the song of a Pine Warbler can sound soft, languid and lyrical; or more mellow and rich; like a delicate, pretty rattle; or a somewhat insistent purr. Occasionally it’s almost a dry monotone, like a Chipping Sparrow; more often, it’s a fluctuating, pulsing, floating warble – though in all of the variations, it’s still a recognizable Pine Warbler’s trill.
This morning I listened to two Pine Warblers singing at the same time, in different directions from where I stood. One sang from the pines in the old field. Its song was a classic sweet trill, but at the end of each trill, it dropped down to a lower pitch, just for a couple of notes. The Pine Warbler in the other direction sang a slower, more fluctuating series of notes with a sensual, pulsating rhythm – still a trill, but a quite different effect.
I don’t know how much the differences reflect different meanings or moods, and how much they reflect the voices and inflections of individual birds. From what I’ve been able to learn so far, it seems to be some of both.
The species account in Birds of North America Online notes that Pine Warblers are known to have more than one song type and may alternate types during periods of singing. Songs may vary in speed or frequency, and sometimes males sing two-parted songs, with trills of different frequencies and other variations. Beyond this, it says, little is known about their repertoire and delivery of songs.*
* Paul G. Rodewald, James H. Withgott and Kimberly G. Smith. 1999. Pine Warbler (Dendroica pinus), The Birds of North America Online (A. Poole, Ed.) Ithaca: Cornell Lab of Ornithology.