[Tweeters] early Cassin's Vireo vs Purple Finch (heard only)

[Steve Hampton]

I'm putting this out here because I see it's not yet been brought up this
spring.

Purple Finches have a “disjunct song” that sounds remarkably like the
classic Cassin’s Vireo “question-answer” song. This fooled me the first
time I heard it. What’s more, PUFI tend to give this in March and April,
just before Cassin’s Vireos arrive in spring migration. If you hear an
early Cassin’s Vireo, it’s been suggested there’s a 110% chance that it’s a
Purple Finch. I know that's not quite true -- I've seen a lot of early CAVI
reports on eBird but at least one had a photo and several others mentioned
visual confirmation. If your first Cassin’s Vireo of the year is
heard-only, it’s worth trying hard to confirm with a visual, or wait and
see if it launches into a typical Purple Finch song (which sounds a bit
like the spiralling song of the Swainson's Thrush, though more warbling
than ethereal).

Cassin's Vireo should just be starting to arrive about now, but don't
really peak for a few weeks.

Three examples of the Purple Finch’s "disjunct song" are here:
https://academy.allaboutbirds.org/peterson-field-guide-to-bird-sounds/?speciesCode=purfin&species=Purple%20Finch%20-%20Haemorhous%20purpureus

Some examples of Cassin’s Finch’s "question-answer" song are here:
https://academy.allaboutbirds.org/peterson-field-guide-to-bird-sounds/?speciesCode=casvir&species=Cassin%27s%20Vireo%20-%20Vireo%20cassinii
good birding,

Steve Hampton
Port Townsend, WA  (qatáy)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman11.u.washington.edu/pipermail/tweeters/attachments/20220418/6bfb8e95/attachment.html>