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Purple Finches: Male or Female?
- To: carolinabirds@duke.edu (CAROLINA BIRDS)
- Subject: Purple Finches: Male or Female?
- From: "BILL HILTON JR. (Hilton Pond Center for Piedmont Natural History)"<hilton@hiltonpond.org>
- Date: Mon, 7 Feb 2000 20:56:29 -0500
- Sender: carolinabirds-owner@acpub.duke.edu
CarolinaBirders . . .
The thread on sexing Purple Finches (PUFI) at the feeder has been interesting.
As usual, Donna Bailey (see below) is right on with her supposition
that a "brown" PUFI with a pink wash might be an older female rather
than a young male. Sometimes brown PUFI also have a gold rump or
wash; I haven't looked hard at my data on this phenomenon, but I have
a gut feeling that these are more likely to be young males.
It's difficult to get an accurate sample of sex ratios in PUFI
without banding them; I'm fortunate to have that privilege, and have
found here at Hilton Pond that red (actually, I prefer "raspberry")
After-Second-Year male PUFI make up about 28% of the winter
population, while about 72% of them are brown, i.e., old females,
young females, or young males. If we make a flying leap of faith and
assume the M:F ratio among PUFI is roughly 1:1, we might conclude
that each of these three age/sex classes makes up about a third of
the brown birds.
There's a longer discussion of this topic on my new website for
Hilton Pond Center for Piedmont Natural History at
http://www.hiltonpond.org. (You KNEW I'd get a plug in somewhere,
didn't you?) I've posted a paper I wrote in 1994 for North American
Bird Bander about banding PUFI and House Finches at Hilton Pond; it's
in the section on "Technical Publications" and includes some photos
that didn't appear in the original article. I hope this section
proves useful to someone. :-)
Now I guess I'll have to stay up all night trying to figure out if
gold-rumped PUFI really are young males . . . . .
Happy Birding!
BILL
***********
>While my memory grows creakier with each passing day, I do seem to remember
>reading somewhere that older female Purple Finches could develop a pink wash
>across the breast, much as adult female Hooded Warblers sometimes have an
>almost complete "hood" and adult female Wilson's Warblers sometimes have a
>"black cap" nearly as extensive as the males. Still, the young male Purple
>Finches should show pink across the breast and at least a pink flush in the
>face, while the older females would have no pink in the face.
>
>But, yes, Janine, in general, the sex ratio at my feeders seems to run
>pretty close to 1:1. Usually, there is one more male than females and I
>don't think that is a "bias of the eye". I have an easier time picking out
>female Purple Finches that male Purple Finches because the female's white is
>so bright and "clean" amongst the buffier House Finches. As a matter of
>fact, last Sunday around here when the weather was nasty and I watched the
>feeder all day, eventualy tallying twenty Purple Finches in view at one
>time, the crowd was mostly male - there were 12 or 13 males to 7 or 8 females.
**********
BILL HILTON JR., "The Piedmont Naturalist"
Hilton Pond Center for Piedmont Natural History
1432 DeVinney Road
York, South Carolina 29745
USA
e-mail: <hilton@hiltonpond.org>
Voice: (803) 684-5852
eFax: (503) 218-0845
Operation RubyThroat Website: <http://www.rubythroat.org>
Hilton Pond Website: <http://www.hiltonpond.org>
"Never trust a person too lazy to get up for sunrise or too busy to
watch the sunset."
BHjr.
**********