[Birdtalk] It's a starling (I think)

[Mark Stackhouse]

Hi Jim,

Brown-headed Cowbird is not a bad thought for this confusing bird, and 
you've caused me to review my original conclusion, which is that the 
bird is a female or juvenile Cassin's Finch. One of the things that 
makes this one tough is the fact that this bird has been bathing, so 
that plumage features are darker and less discernible due to the 
feathers being extremely ruffled. However, some things can even be seen 
in the plumage - though we're probably better off using structural 
characters as much as possible for this i.d.

The first thing that said Cassin's Finch to me was the bill. Cassin's 
Finch has a very straight culmen (that's the ridge or line formed by 
the top and bottom of the bill), which separates it from other finches 
like House Finch. However, cowbirds also have a rather straight culmen, 
especially in the lower mandible. But if you look at a cowbird in 
profile, like many icterids (blackbird family members), the top of the 
bill forms a line right onto the forehead and across the top of the 
head in a rather flat profile. The "quiz" bird shows a steeper forehead 
that rises from the bill to a peak behind the eye - just like a 
Cassin's Finch has. This is especially visible in the second photo. I 
also thought the bill was a bit short for a cowbird, but this can be 
hard to judge.

Other structural features that point to Cassin's Finch include the 
general shape, which looks too round in the body and short in length - 
cowbirds are a bit longer and lankier looking. The tail is the wrong 
shape, and I think, a bit too short. Cassin's Finches have notched 
tails, which can be seen in the first photo, but cowbirds have more 
rounded tails.

Now to the plumage features that we can use. There's not much here, but 
both photos show the pale post-ocular patch that's so distinctive on 
the head of female and juvenile Cassin's Finches, contrasting with a 
darker crown, something that shouldn't appear on a cowbird Also, both 
photos show a distinct, thin eyering, again a feature of Cassin's 
Finch,, but not of cowbird.

This was a interesting puzzle and illustrates how difficult i.d. from 
photos can be - and how different it is from field i.d. where so much 
more in the way of behavior, etc. is useable. With photos it seems as 
though we always end up with a fine analysis of minute features.

Good birding!

Mark Stackhouse
mark at westwings.com
801-487-9453 (Salt Lake City, Utah, USA)
011-52-323-285-1243 (San Blas, Nayarit, Mexico)

On Jul 29, 2006, at 8:04 PM, Jim Bailey wrote:

> I think the consensus is wrong on the #1 bird. I don't know how a 
> cowbird can be mistaken for a cassin's finch. I agree on the other 2 
> birds.
>
> I'm going to dangle here in the wind with my opinion :-(
>
> Fun quiz, Carol.
>
> Jim
>
> ----- Original Message ----- From: <cldavis at xmission.com>
> To: <birdtalk at utahbirds.org>
> Sent: Saturday, July 29, 2006 7:40 PM
> Subject: [Birdtalk] It's a starling (I think)
>
>
>> I finally decided to do an image search on Google for an immature 
>> starling
>> and after a few non-ringers, I came up with an almost identical bird 
>> to the
>> #3 bird in the quiz.  Thanks to all who contributed their 
>> opinions--it was a
>> lot of fun!
>>
>> The concensus of opinion on the #1 bird seems to be Cassin's Finch 
>> and the
>> #2 bird, Pygmy Nuthatch.  I guess the thing to remember in birding 
>> and in
>> life itself is what appears to be a beautiful Northern Flicker may 
>> just
>> turn out to be a European Starling. Here's the link:
>>
>> http://gunnarpettersson.com/mapparna/filerna.asp?mapp=225Stare
>>
>>
>> Carol
>> P. S. I could have sworn that was a flicker...
>> _______________________________________________
>> Birdtalk mailing list
>> Birdtalk at utahbirds.org
>> http://utahbirds.org/mailman/listinfo/birdtalk
>
> _______________________________________________
> Birdtalk mailing list
> Birdtalk at utahbirds.org
> http://utahbirds.org/mailman/listinfo/birdtalk
>