dowitchers

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: After a bit of research and some further muddled thought, I'm almost ready to conclude that these birds most closely resemble hendersoni Short-billed. Perhaps they are hendersoni-like caurinus, or are intermediate in some sense. Having no personal experience with that race I'm not sure what to think. I'm also not sure of the actual status of birds from hendersoni breeding range on the west coast. : With these birds the color on the underparts seems to extend down quite far onto the central belly, with traces of color even remaining on the mostly faded birds. This isn't supposed to be typical of caurinus (although they are variable) and to the extent this can be accurately judged in the photo, suggests hendersoni or Long-billed. However, based on a small sample of photos viewed and on some admittedly rusty personal impressions from ancient history, I'm not sure Long-billed in any state of plumage would typically show such pronounced, contrasty, complete, and straight barring across the alternate scapulars as is apparent on these birds. Maybe they are more variable than I realize, but I wasn't able to find a Long-billed photo with a scapular pattern anywhere near what is evident here. Long-billed do have contrasty white tips to the alternate scaps when fresh, but the notching and barring on these feathers seems to most typically be a fairly deep rust or buff color that shows comparatively minimal contrast with the dark scap centers. My impression is also that any buff notching or barring is most often angled inward from either edge, with the longest "bars" forming chevron (or zigzag?) shapes rather than straighter lines across the feathers. The chevron shapes also often seem broken at the shaft - not forming a continuous line across the feather. I'm not sure how much the bar/center contrast could increase on Long-billed as they fade, but I don't think the patterning would change that much with wear or fading. : Alternately, of all the dowitchers, hendersoni Short-billed seem to at least on average have the most pronounced and contrasty barring across the alternate scaps. Their scaps seem to start out with barring that is fairly pale buff and showing relatively high contrast with the dark centers in fresh plumage, and it wears even paler and more contrasty. I suspect at any stage of plumage hendersoni would have much more obvious internal markings on the scaps than a Long-billed at a similar stage. The barring on hendersoni also seems typically less angled and much straighter across the feathers than Long-billed, and many or most bars are complete - not broken at the shaft, forming a continuous line across the feather. The bars may also be wider on average than on Long-billed. This seems to give hendersoni the sort of zebra-striped look I mentioned, particularly when they start to fade and lose color. The above differences may also be true to a less obvious extent of the tertial barring, but I haven't looked closely at that as much. : My very rough impression is that caurinus Short-billed are sort of on average intermediate in many aspects of feather barring, including typically showing more bar/center contrast than Long-billed, but less than hendersoni. Some seem to show less pronounced and steeper angled notching or barring than an average hendersoni. : As far as can be judged, the birds in question all seem to have pronounced true barring. Rather than notches, broken chevrons, or zigzag patterns, the bars seem comparatively straight, solid, and unbroken across the feathers. The bar/center contrast is also quite pronounced. This seems obvious even on the fresher-plumaged birds, giving them a look that would seem strange for Long-billed to me. The zebra-striped look is most obvious on the remaining alternate scaps (and tertials) of the bird with most progressed molt, because its missing feathers expose more of their surfaces (and bars). : Looking at the freshest bird, the barred flanks combined with the relatively weakly marked sides, and defined, irregular, but comparatively not-so-dense spotting on the sides of the breast also seems to most closely match adult hendersoni of all the dowitchers. Both caurinus and Long-billed typically show more markings on the breast and sides in fresh plumage, however wear and fading make this very subjective, and I'm not sure it's more than a supporting mark for birds at this time of year. : I'm not so sure anymore that what's visible on the right bird is partly actual tail or all uppertail coverts, so perhaps that isn't a useful mark, at least with the low resolution of this photo. It's also hard (at least for me) to judge for sure if any of these birds are actually missing primaries, so perhaps the molt timing of the remiges isn't necessarily an issue based on this photo. : This is all stuff I'm just learning, or relearning after a long hiatus from shorebird watching, but I thought I'd throw the above comments out there anyway as things to look at. It wouldn't surprise me if I'm off base again as I've been in an "insight" slump lately, but for whatever it's worth I'd still have to vote for all Short-billed. Where's the audio portion of this quiz??? : Cheers, : Phil

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