Greetings All

Today I was among the throng of birders looking for Hoary Redpolls. Among the
Commons, there was an interesting female redpoll, found by Sam Terry and/or
Kevin Aanerud. The bird definitely had NO streaking on the undertail coverts.
It also had a distinctly marked rump. I strongly suspect (as did Kevin and
Sam) that this bird was an aberrant Common.

This brings up an important point. Separating such similar species,
especially when one is a vagrant, needs to be based on more than one ID
point. I don't have the excellent Birding article by Czaplak immediately at
hand, but from what I recall, only three marks are (supposedly) definitive
for Hoary:

1) large unmarked rump patch
Some Commons can have small unmarked areas on the rump, and adult males
sometimes have an entirely unmarked, but rosypink, rump.

2) unmarked undertail coverts
Yes, some Hoaries can have a single fine streak on the undertail coverts, but
this is rare (from what I remember of a search at the Field Museum of Natural
History, less than 10 percent, and maybe less than 5 percent). No Hoaries
should have multiple undercovert streaks. A single streak can also be shown
on Common Redpolls, and indeed, a couple birds seen today showed this. Thus,
a redpoll in Washington with a single undertail streak, just by probability,
is much more likely a Common. I would suspect that Commons with lightly
marked undertail coverts would also be more lightly marked on the flanks and
elsewhere.

3) contrastingly pale lower scapulars.
The scapular mark is only shown on some Hoaries, so if it is absent, Hoary is
still a possibility.

The bill shape/size can be quite useful, but is very tricky.

Other marks, such as flank streaking and face coloration, show virtually
complete overlap.

I am not saying that anyone did or did not see Hoary Redpolls, but I felt a
note of caution was warranted, especially given the odd bird seen today.

Cheers
Steven Mlodinow
Everett WA
SGMlod at aol.com



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