Outside opinions on record 2003-25

Note from Steve Summers asking for "outside" opinions:

I was wondering if you could send me your impressions on the attached thrasher photos. These were taken in St. George UT on 21 June 2003. I'm leaving for Ecuador for 3 weeks next Sat. so if possible could you answer this before then? Here are their replies.

  
From Guy McCaskie (Calif.)

Steve,

Difficult. I believe the bird is a Curve-billed/Bendire's Thrasher. Of the two, the length of the bill, the lack of paleness at the base of the lower mandible, and the apparent grayish wash on the flanks, all lead me to Curve-billed Thrasher. The evident lack of markings on the breast, and apparent lack of faint wing-bars could be a result of wear, or the fact that the bird was hatched this year.

Guy

From Paul Lehman (New Jersey)

Hi Steve:

The thrasher looks like a worn Curve-billed to me. Certainly Crissal and Le Conte's don't fit for various reasons. The only other, but closest, choice is Bendire's, and that bill looks too good for Curve-billed and too long and decurved for even the "extreme" Bendire's to me. Too bad one can't see any breast spotting in the two photos, but it could be wear or it could be an artifact of the photos, or a combination of the two. Any comments from others?

I just got back from leading a Pacific NW tour in WA and BC. Highlights were Y-b Loon, Emperor Goose, and WA's third-ever Wilson's Storm-Petrel. There's been Little and Red-nk stints here in NJ, but I've seen neither. I did go on a quick chase to WV last week to see the stakeout Green Violet-ear there.

Have a great trip next week. I'm off myself on Aug 13 for my w. Alaska tours and long stay-on at Gambell afterwards. Not back until early October.

Paul

From Jon Dunn (Calif.)

Hi Steve,

Sorry, but I was away in Arizona, New Mexico and Chihuahua so did not get your message. By the way I finally saw Thick-billed Parrots in Chihuahua-spectacular. I think I recall you seeing them back in December of 1973 at Rancho Liebre.

Anyway, the bird to me is pretty clearly a Curve-billed Thrasher. I say this because of the obviously long and strongly decurved bill that appears entirely black. The bird is worn so it's hard to judge the patterning of the spots. I see pretty prominent white tail spots. Obviously the bird can't be a Crissal Thrasher with tail spots and a white crissum, so the issue becomes whether it's a Bendire's and I think that possibility is eliminated by bill shape and color. I also think a Bendire's would be buffier.

If I was on the Utah committee I'd vote to accept as Curve-billed based on the photos alone.

All best,

Jon

*** Note from David Sibley  ***

I asked David Sibley about juvenile Crissal Thrasher plumages, and eventually sent him Ed's photos from record 2003-25. His response is attached below.  ~ Rick Fridell

-----Original Message-----
From: David Sibley
Sent: Friday, November 14, 2003 7:26 AM
To: 'Rick Fridell'
Subject: RE: Request for Thrasher ID

Rick,

Thanks for your note and the photos. I was intrigued, since I couldn't answer the question about juvenile Crissal Thrashers. So I went to the collection at Harvard yesterday and checked the specimens there, and with some reservations I think it is safe to call the bird a Curve-billed.

Basically a juvenile Crissal looks like the adult, with brick-red undertail coverts, but with a shorter bill. So the strongest point in favor of Curve-billed rather than Crissal is the pale buff-colored undertail coverts matching the belly of this bird. The bill shape is perfect for Curve-billed, but on the rest of the bird there is very little to go on - tail pattern, wing pattern, head pattern, etc are all similar enough that the photos offer no evidence either way. My only reservation in calling it Curve-billed is the fact that no breast spots are visible in either photo. However, given the poor quality of the photos, and the fact that some Curve-billeds from
Arizona have very weak spots, I think this is acceptable.

It is safe to say that this is not a Curve-billed from one of the more southerly or easterly populations, which have more contrasting spots below, and distinct white tips on the wing coverts and tail feathers. If accepted as a Curve-billed it has to be the subspecies palmeri.

Hope this is helpful,
David Sibley