Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!deimos!unmvax!nmtsun!john
From: john@nmtsun.nmt.edu (John Shipman)
Newsgroups: rec.birds
Subject: Re: Finch identification
Summary: It's subtle and tricky
Message-ID: <3837@nmtsun.nmt.edu>
Date: 24 Feb 90 08:17:33 GMT
References: <5896@blake.acs.washington.edu>
Reply-To: john@nmtsun.nmt.edu (John Shipman)
Organization: Zoological Data Processing
Lines: 37

Ann Harrington (annmh@blake.acs.washington.edu) writes:
+--
| My birdfeeder attracts a lot of finches of the Purple/Cassin's/House
| variety.  What I'd like to know is, does anyone have any clues as
| to how to tell these three varieties apart?...
+--

Discriminating among these three forms is tough, because all
are highly variable.  My neighbor Phil and I have had all
three forms in our backyards, although the Purple was a
notable rarity.

Disclaimer: I'm not an expert, and in general it's a bad
idea to try to identify birds on the basis of one or two
characters.  These are just the marks that have worked for
me.

The first thing to look for is the presence or absence of
a strong facial pattern.  The Cassin's and Purple have a
clearly marked dark ear patch, with a clear light line
above and below it.  The House Finch does not have a
strong, sharply delineated facial pattern.

Distinguishing Purple from Cassin's is much harder.  The
bill of the Cassin's is a trace longer and straighter, while
that of the Purple is not quite as long, and the top and
bottom edges are slightly curved in profile.  This
distinction is tough unless you have both forms occurring
together and can get long, close looks at them.

Don't expect always to be able to ID every finch you see,
but with time and direct comparisons you should be able
to call most of them.
-- 
John Shipman/Zoological Data Processing/Socorro, New Mexico
USENET: ucbvax!unmvax!nmtsun!john  CSNET: john@jupiter.nmt.edu
``Let's go outside and commiserate with nature.''  --Dave Farber