Mystery Bird: Black-necked Stilt, Himantopus (himantopus) mexicanus

tags: , , , , ,

[Mystery bird] Black-necked Stilt chick, Himantopus (himantopus) mexicanus, photographed on Bolivar Peninsula, Galveston County, Texas. [I will identify this bird for you in 48 hours]

Image: Joseph Kennedy, 27 May 2007 [larger view].

Nikon D200, Kowa 883 telescope with TSN-PZ camera eyepiece 1/1000s f/1.0 at 1000.0mm iso400.

Please name at least one field mark that supports your identification.

Review all mystery birds to date.

More like this

From what I can see of the beak, it's a wader chick - and from my observations of it's European relatives and checking the odd photo on the web, I'd go for American Avocet.

By Paul King (not verified) on 10 Mar 2010 #permalink

Get dowwwwn...

It's not completely clear to me if that's water or very fine sand. If water, then it's definitely a walrus; if sand, then it's probably a beached walrus.

The identification would be more certain if there were some oyster shells and a carpenter nearby.

Nice thing about downy young -- since they can't fly, range maps are much more reliable -- you don't get too many vagrants at this age.

Turns out there are only 6 species of shorebirds that nest on the Texas coast (surprised me, actually, I was expecting 3 or 4 more). Willett, American Oystercatcher, Wilson's Plover, Killdeer, American Avocet, and Black-necked Stilt.

Turns out there are only 6 species of shorebirds that nest on the Texas coast ⦠American Oystercatcher, â¦

and

The identification would be more certain if there were some oyster shells ⦠nearby.

Proof! It's definitely a walrus.  ;-)

Thanks for the breakdown Paul... let's see...

I have no idea what key field marks are used when identifying chicks other than looking for the parents (!) but it appears to me that one might be the extent of that eyeline and another, which should eliminate a couple from Paul's list, the tone/pattern of coloration but I suspect that is probably very variable...

I think we we can easily eliminate an American Avocet chick because it should be more "black and white" rather than "brown and buff" and also an American Oystercatcher chick because of the bill color, and lack of mottled coloration on the head and especially back...

By David Hilmy (not verified) on 10 Mar 2010 #permalink

the Willet chick seems to show the "brown and buff" but has a longer eyeline to the rear of the eye (is that age-related?) and apparently either a longer forward extension to that eyestripe or dark lores... but it appears that the Black-necked Stilt chick matches coloration, mottling, and the eyestripe... I guess if the bill was visible we could see how much shorter would the Willett's as compared to the Black-necked Stilt, but I think it is indeed the latter

By David Hilmy (not verified) on 10 Mar 2010 #permalink

I agree with the Black-necked Stilt. According to Baicich and Harrison (A Guide to the Nests, Eggs, and Nestlings of North American Birds), Willett should have a darker crown, instead of the thin dark stripe. I think it's harder to rule out American Avocet based on their work, although David's link certainly shows a very pale chick. I do wonder if there's some age-based variation, simply because B&H describe them as pale grayish-buff. They do seem to show less mottling, and fewer black patches above.

Hmmmm...

After checking the rest of David's links, I'm thinking there's considerably more variation than I had realized -- I'm not sure how many of those I would have gotten using B&H. Some of that may be geographic, especially with the Willett. There are two subspecies, and O'Brien, Crossley, and Karlson state that the two could be separate species.

I think I'm to the point where I'm going to agree with David, and then throw up my hands. Every time I look at something new I feel like I know less than I did before.

Hey Paul, one thing that I did find consistent with the American Avocet was that the eyeline extension rear of the eye (as seen in my first example) is very prominent, whereas ours is very slight, if at all..

American Avocet chick 1

American Avocet chick 2

By David Hilmy (not verified) on 10 Mar 2010 #permalink