Subject: Re: Strange Flycatcher
Date: May 5 13:58:28 1998
From: CHARLES E SWIFT - charless at umich.edu


On Tue, 5 May 1998, Michael Price wrote:

> Hi Tweets,
>
> Jane Westervelt writes:
>
> >In my experience, PS flycatchers commonly drop the first note of
> >their call, which, from my understanding of the differences in calls,
> >would make them sound like a Cordilleran. I've sat and watched
> >the same bird make both calls like you describe on numerous
> >occasions.
> >With that in mind, I'd like to think there was more reasoning than
> >song behind this split.
>
> Jane, I wish this made things simpler but it doesn't. Pacific-slope
> Flycatcher Empidonax difficilis is a common breeding bird in this type of
> habitat in Vancouver BC and while I heard a number of territorial and
> near-nest vocals, this is the first time I've heard the Cordilleran
> Flycatcher E. occidentalis call. Dick Cannings once played a tape with both
> their calls, and the Stanley Park bird was giving an exemplary occidentalis
> call, not simply dropping a note, unless the occidentalis call is simply the
> result of dropping a note.
>
> Which raises the question: how do you then separate difficilis from
> occidentalis without a sonogram dingus? Wotta headache this split has turned
> out to be.
>

Apparentley a lot of Northern Idaho birds give both calls which has made
them virtually impossible to seperate. Some folks who have lived here
longer than I can probably provide more information on this problem.

Thanks, Charles.

charless at umich.edu