Yellow Grosbeak one-bird theory

[Owen Robertson]

Hi all,

While going over photos of the Gilpin, Larimer, and Arapahoe Yellow Grosbeaks from this year, Archer Silverman and I noticed that all the birds show a small patch of missing feathers just below the right auricular. This feature isn't visible in all photos, even those of the right side, and we believe that to be the result of the bird holding its neck in such a way that adjacent feathers cover up the patch. However, it is still very consistent, and does not seem to be the result of misaligned feathers - it really does seem to be a lost patch of feathers. Because of this, we believe that all three records pertain to the same individual bird, which if true is almost as surprising as three separate birds! (Of course, it's also possible that the Hinsdale bird was the same individual, but the one photo we have doesn't show this mark). Another possible field mark we noticed is that on the left side of the bird's face, the auricular shows a noticeable dusky mark, but this could be due to the visible shafts of the auricular feathers and seems less individual. This also means that this bird almost certainly passed through Jefferson, Boulder, and perhaps even Denver counties on its travels. It's also a good reminder that when/if it stops coming to the Estes Park feeder, it could truly show up anywhere, so keep your eyes peeled! Below are photos from each location, demonstrating this field mark:

Larimer: ML638545906 photo copyright Linda Chittum

Gilpin: ML637845104 photo copyright Christian Nunes

Arapahoe: ML635348347 photo copyright Joy Lake

Any thoughts on this are greatly appreciated!

Good birding,

Owen & Archer

[chob...@gmail.com]

Interesting, but do we know if such feather arrangement is atypical of all Yellow Grosbeaks?

 

Chris Hobbs

chob...@gmail.com

--
--
You received this message because you are subscribed to the Google Groups "Colorado Birds" group.
To post to this group, send email to cob...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/cobirds
* All posts should be signed with the poster's full name and city. Include bird species and location in the subject line when appropriate.
* Join Colorado Field Ornithologists https://cobirds.org/membership/
---
You received this message because you are subscribed to the Google Groups "Colorado Birds" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+u...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/cobirds/6da38e7a-6d16-45ca-9c0e-5da0deb5ea2dn%40googlegroups.com.