A bell-like trill

[vaneramos]

Friday afternoon: clouds near Caledon

Another photo is posted in weather_pics.


Every year I participate in the North American Breeding Bird Survey. I wake up before dawn one morning in late June and drive 40 kilometres through cottage country, making frequent stops to identify every bird I can see or hear. Most counting is done by ear, so I have to recognize every song I'm likely to encounter. Some are unforgettable, like the weird call of an American bittern, but others require an annual refresher. Yesterday afternoon was spent downloading sound files for a reference disc.

Some vocalizations are harder to distinguish. I'm perplexed by the bell-like trills of the chipping sparrow, pine warbler and dark-eyed junco. Sometimes circumstances are a giveaway. Along the Eramosa River in winter, it could only be a junco.

Starting my route at 4:54 a.m. at the gas station in Dwight surrounded by statuesque white pines with the air full of overlapping trills, I'm almost certain they're pine warblers. But in the dawn light I can't fix my binoculars on a single bird. Every year I promise myself I'll go there a day ahead, with the luxury of standing for an hour until one singer shows his head and solves the problem once and for all.

Comments

[bill-bill.livejournal.com]

I spent many a minute standing at a BBS stop hoping the bird would sing one more time so I could be certain before putting it down as a pine warbler or a chipping sparrow. I've generally found chipping sparrows to be a tad drier, pine warblers to be clearer, more musical in tone, and juncos to be, well, hmmm.. the notes have a shape to them, a bit of upslur to each note. And the trill is a bit slower, which is probably why us humans can hear the shape of each individual note.

You can always just cross your fingers and hope they'll give a chip note, since the three have very different chips...

Around here pine warblers are highly localized, and juncos are only above 3000' elevation in the summer, but we've got worm-eating warblers thrown into the trill mix as well. But they tend to be buzzy and dry, not so musical as those other three.

Is your BBS route far enough north for orange-crowns? I've always picked them out as having a trill that is faster, thinner, and tends to drop in pitch at the end like the bird is running out of air.

[vaneramos.livejournal.com]

No, the cottage isn't far enough north for orange-crowns. They're not easy to find at Pelee during migration, either (I grew up on the Lake Erie shore just a few miles from the point). As a matter of fact, I think it would be a life bird for me.

I thought the pine warbler was more musical, but as I never saw one singing before yesterday, it was always guesswork. Hearing that colony in the pines yesterday has given me more confidence. It's interesting how one experience can fit the missing piece in a puzzle.

Listening to junco songs on the web, I've noticed a lot of regional variation. The ones we get around here in winter have a pretty rapid trill, but it is more musical than the chipping sparrow. Again it's harder to be certain on the BBS because the forest is dense and the vast majority of identification is by ear. Add to that the fact that I'll hear up to eight or nine species at a single stop, and it's sometimes overwhelming.