Friday, May 11, 2007

The Brewster's Back

It's been a couple of days since I got out back--last time, not a warbler to be heard (although I've heard a black-and-white a number of times from across the street over the last ten days or so). Last weekend hummingbirds, house wrens, and chimney swifts arrived in the hamlet--now tree swallows and wrens are squabbling over the two nesting boxes in the yard. Chipping sparrows are getting very serious in their various battles and courting dances. Then this morning, warblers. Out in the far field, my old friend the Brewster's Warbler was singing from the same perches that have accomodated this bird over the last few years. Joining him, one of those American place-name warblers, Nashville, I think. Didn't get the best look, and don't know the song well enough to be sure. In the woods beyond, an ovenbird and a wood thrush sang.

The Eastern Towhee has been back for a while now--but there seemed to be a number of them singing back there this morning. And at least one of them was letting me get much better looks than I normally do of this bird. The towhee has been a difficult bird for me for some reason. It took me years to learn its song. It has a very distinctive call and song, very beautiful. And for several years at first hearing it sounded like something marvellous I'd never heard before. Last year I felt like maybe it'd sunk in. And, voila, this year I knew the call the first time I heard it. Today I was treated to the song as well.

The Brewster's has never been a problem. It's song is distinctive and memorable, for me--at least the song sung by my birds. This bird, a hybrid of the Golden-winged and Blue-winged Warblers, was one of the most interesting things I discovered during my days as an atlasser. The expansion of the range of the Blue-winged Warbler has been a problem for the Golden-winged, or at least has added to its troubles. The birds are very closely related and hybridize happily. The consequence is likely to be the eventually swamping out of the Golden-winged Warbler. (Click here for the Golden-winged Warbler Atlas Project at Cornell) I had a Golden-winged singing in the far field for most of the summer of 2004. Since that summer it's been all Brewster's. The next year, 2005, I saw a Brewster's in the company of a female Blue-winged Warbler, both carrying food for nearby, noisy fledglings. My surmise is that the 2004 bird mated late, with a blue-winged, starting the dynasty that still breeds back there. The bird I saw this morning was singing the same mixed song I know so well, and had the classic Brewster's markings, except that he had yellow under his chin as well as on the top of his head. Others have a different idea of the classic Brewster's, this page has photographs of a couple of interesting examples, and a blue-winged for comparison.

The Golden-winged warbler has recently been designated a "species of special concern" in Ontario.

2 comments:

John said...

I initially had trouble with the towhees, also. I think that part of the problem is that not all birds sing the standard "drink-your-tea" song. Instead there seem to be a bunch of variants with different numbers of initial syllables that can make it sound like a different species.

Pamela Martin said...

That there are variant singers among towhees is certainly true--after I wrote the post I went and checked the exemplar of the towhee song at Wildspaces--quite different from the song I heard this morning. But I do think that I hear quite a similar song every year--some sounds just seem harder to file in the brain than others.

Brains, of course, differ too. Translations of song into English words only rarely helps me--thinking too much impedes identification for me too. The only things that seems to work for me for most songs is lots of experience of the singing bird, and the occasional good look.