This page discusses an odd godwit, initially identified as Bar-tailed Godwit of the Siberian race baueri, that was discovered from Moonglow Dairy on Elkhorn Slough on 26 Oct 2003. The bird remained into November and has been nicely documented with photos, some of them shown below. For reasons detailed here, and as first proposed by Dan Singer on 10 Nov, this is actually an aberrant Marbled Godwit.

NOTE: The abbreviation "MTY" means "Monterey County" in the text below. Text by Don Roberson. Photos on this page are copyrighted by the photographers to whom they are attributed, and may not be reproduced in any form (including other web sites) without the express consent of the photographer.

The godwit was initially discovered on a small pickleweed-covered islet at high tide at Elkhorn Slough, seen from the easternmost dike of the Moonglow Dairy ponds complex, by Don Roberson & Rita Carratello. It was scoped from a distance [a tiny dot at red arrow in top photo] as it stood among many other Marbled Godwits, Willets, and a few other shorebirds. It was identified as a Bar-tailed because of the lack of cinnamon color, its obviously smaller size, a barred tail and rump, a prominent white supercilium, a rather long primary projection, primary tips extended well beyond the tail, and the impression it was slightly short-legged. However, it had odd characters also, as shown in two photos (above; © Bill Hill with a digital camera at very long distance). The following "Identification note" was posted that night on my web site, using more of Bill Hill's photos:
Identification notes: This Bar-tailed Godwit was unusual in several ways, and we are having trouble ageing it. Expected points include: it was obviously smaller than adjacent Marbled Godwits (right) and much whiter below, especially the lower face, neck, belly, and undertail coverts. It showed a long primary projection and the wingtips extended well beyond the tail. A long and prominent white supercilium dominated the face. The rump and tail were barred brownish over white (photo lower right), consistent with the Siberian race baueri.
Odd points, though, include these: the basal half of the bill was a very bright pumpkin orange, much brighter than any other godwit out there. Indeed, the bird was found because of this color What age does this suggest? Further, the sides and flanks were barred, which seems odd for this species, and there was a grayish wash and mottling across the breast.
In the field, we felt that the "pale panel" formed by the wing coverts was consistent with a juvenal-plumaged individual but now, looking at the photos, the wing coverts appear more worn with one or two small dark feathers present. This suggests the worn coverts of an adult. The back is very heavily patterned (near right, just above) which, again, may suggest an adult still in breeding plumage. However, if this is an adult, it seems apparent that the face, crown, neck, and breast are already in basic plumage. If so, are the barred flanks retained alternate feathers? Females can be somewhat barred in alternate plumage (see Peter LaTourrette's Alaska photo) and can lack much red below. On the other hand, juvenal birds can have "pale panels" to the wing coverts (but would they look this uniform?) and can be barred on the flanks (e.g., see Dan Singer's photos and Joe Morlan's details for a late Aug juvenal a couple years ago). Could this be how such a bird would look two months later?
all photos above © Bill Hill
except the distant view of waders on dike by D. Roberson

all in all, an interesting bird;
comments on ageing it are very welcome

Additional photos were taken on 27 Oct [© Anne Spence; see her other images of this bird on her web site] and these illustrated well, among other things, the prominent supercilium and the bill color (below; top), the actual extent of barring below and its configuration (below, bottom left), and the size of the bird next to a Marbled Godwit (below, bottom right). Even acknowledging that there is a size difference between larger females and smaller males in Marbled Godwit, this seemed a small bird.

As the bird lingered, additional photos were taken over various days:
This digiscoped image of the Elkhorn Slough bird [above right; © David Vander Pluym; used with permission] shows a longish primary projection and wingtip extending beyond the tail, not all that much different than that of a known juvenal-plumaged Bar-tailed Godwit in 1997 [lower right; © Dan Singer, taken 31 Aug 1997 in San Mateo Co.].

Disturbingly, though, the top bird appears to have the longest tertial barred (like Marbled) rather than notched with white spots (as in juv. Bar-tailed). This did not seem to be evident in earlier shots.

These foraging shots of the Elkhorn Slough bird (above & right; © John Sorensen, used with permission) showed a bird that looks very worn and is disturbingly long-legged.

Dan Singer studied the godwit late in the afternoon of 9 Nov (with Mark Eaton) and wrote:

"I am currently convinced that this bird is not a Bar-tailed Godwit, but rather an aberrant Marbled Godwit still in (or mostly in) breeding plumage. The lack of cinnamon or tawny-brown tones above and below and the bright orange-based bill are clearly unusual, but otherwise the plumage is a good fit for an alternate-plumaged Marbled Godwit. The bird did not appear to me to have the short-legged, shorter-billed proportions typical of Bar-tailed Godwit, nor did the primary projection appear long enough."

The concept of an alternate-plumaged Marbled Godwit had initially been rejected because of the late October date, the prominent supercilium, the primary projection, and the size. However, compare the shots immediately below. On the left, photos, of Marbled Godwit taken at Sherwood Island SP, Connecticut, in June 2002 (© A.J. Hand, used with permission; photo use facilitated by Marilyn Bakker of the Friends of Sherwood Island web site]. On the right, photos of the Elkhorn Slough godwit in Oct 2003 (© John Sorensen, above, and © Anne Spence, below [image flipped for comparative purposes].

In bill color, structure (bill length, wingtip projection) and barring pattern, the Elkhorn Slough bird does closely resemble the alternate-plumaged Marbled Godwit. That June godwit from Connecticut also has a prominent supercilium behind the eye. The October bird has plumage that is four months more worn than the Connecticut bird, and seemingly consistent with what an alternate-plumaged Marbled Godwit might look like four months later. These points adequately address the initial arguments for Bar-tailed, including the supercilium and wingtip projection.

Commentators in Britain had noted this already. In comments on "Surfbirds" forwarded to the Frontiers of Bird Id. chat line, Graham Etherington wrote:

"The Elkhorn Slough godwit has many features of Marbled Godwit and very few of Bar-tailed. Firstly, judging by the faded wing coverts and patterning on the back, the bird is an adult, not a juvenile. Juvenile Bar-wit has thick, tawny edges to all its wing coverts, and the markings to the underparts are restricted to small blotches on the throat and upper-breast, most unlike this bird."
He also provided links to the Connecticut photos re-posted above.

But what about the small size of the Elkhorn Slough bird? Richard Millington wrote (on the same chat line):

More interestingly still, a smaller subspecies of Marbled Godwit was newly described in 1989 (Condor 91 436-443) see: http://elibrary.unm.edu/Condor/

This limited Alaskan-breeding population ... named Limosa fedoa beringiae ... does not appear in the guide-books (Shorebirds, Sibley etc) or on the maps, and may only differ in size (eg. shorter bill, wing and legs), but a lone male beringiae amongst a bunch of female fedoa could look tiny.

L. f. beringiae probably normally winters along the coast of Oregon and northern California (thus to Elkhorn Slough) amongst the more numerous [nominate] fedoa. No plumage differences are yet described, but the climate anomaly and geographical distribution (which may include a long over-ocean flight) may throw up some plumage and moult differences, perhaps worthy of extra study.

I believe that this evidence is convincing. Dan Singer is right. The Elkhorn Slough godwit is not a Bar-tailed Godwit but, rather, an odd Marbled Godwit, probably a male and possible of the new race L. f. beringiae, that for some unknown reason did not molt out of alternate plumage and is now very worn.

In contacting those with experience with east Asian populations of Bar-tailed Godwit, and especially those who knew the Siberian race baueri, the consensus so far is that baueri is variable in some respects (including the extent of barring below) but that they had not encountered a bird like the Elkhorn Slough godwit. For reference purposes, here are two fine shots of baueri Bar-tailed Godwits in juvenal plumage (above) and in basic plumage (below).

Juvenal-plumaged Bar-tailed Godwit
   race baueri
12 Oct 2002 in Japan
© William Hull (used with permission);
see his World Bird Guide web site.
Basic-plumaged Bar-tailed Godwits
   race baueri
Nov 2001 in New Zealand
© Angus Wilson (used with permission)

Note variation in underparts, including
presence of barring and its extent

Finally, having misidentified the Oct 2003 Moonglow Dairy godwit, some may be wondering about the Bar-tailed Godwit that Rita & I found on 5 Sep 1994, also on Elkhorn Slough and adjacent to Moonglow Dairy. Here is my photo of that bird (right; © D. Roberson). For the moment, I am sticking to that claim.....

Many thanks to all the photographers who contributed to this page. Also many thanks to Dan Singer for sorting out this mess.




Page created 12 Nov 2003