Thanks to Duncan Rothwell who has been in correspondence with a friend of his Peter Davey, in Cayman, who is clearly something of a dowitcher nut.
While I am by nature a fairly shallow fellow and tend to avoid posting serious id material (far cleverer folk than me do it far better), Peter’s dowitcher pointers are very interesting.
Duncan sent pictures of the Marshside bird (still present today at the back of Crossens Inner) to Peter and has asked me to share his response on the Birdblog, which I’m happy to do.
Peter says: “My immediate impression (from the photographs you sent) is of a Long-billed Dowitcher, which is what you thought.
1) The feathers on the back are brownish, not grayish or silvery, with dark feather centers. This is pretty well diagnostic.
2) Bill base is narrow and much the same colour as the bill itself, which is pencil-straight and without the the downward kink of the S-b D at the outer two-thirds of the length. The S-b Ds typically have a thicker, greenish, bill base.
3) The eye crescents are more prominent than with the S-b D. This is not mentioned in the books, but it’s a pretty constant observation that I have made over the years.
4) The primaries are slightly shorter than the tail feathers.
5) The overall shape is rounder than an S-b D, back and chest.
It’s tricky to judge, but the neck and side of breast look to be an even shade of gray, typical of L-b Ds.
6) Bill to head ratio tells you nothing in this case, as it is 1:1.5, right in the middle of the range shared by both species.
That’s all I can say so far. Photos of barring on tail and head from directly in front, showing crown, would help too. The L-b D has a dark, triangular crown with straight sides. With the S-b D, seen from the from the front, the triangle has concave sides, as the supercilia are wider and higher. This not 100% diagnostic, but probably 90% true.
The white bars on the tail are almost always narrower that the black bars on the L-b D. The opposite is true with the S-b D, where the white bars are wider, giving the impression of a paler tail when in flight.
That’s all I can reliably say from these photos.
In any case, I’m 100% sure it’s a Long-billed Dowitcher.
Here is a list of the main differences between the L-b D and S-b D in winter plumage.
It’s not exhaustive, but it covers most of what I’ve learned about winter plumage, anyway.
Our short-bills are almost exclusively subspp ‘hendersoni.’
* Narrow, dark bill-base.
* Bill straight, with only slight downward bend, tapered and narrow along length.
* Only L-b D has bill longer than 1:1.8 x head length
* More acute loral angle than S-b D.
* Supercilium is straight.
* Dark triangle on head has straight sides.
* Small pale patch on chin, so looks darker when asleep.
* More rounded back and chest, ‘as if swallowed a ball,’ so back feathers sometimes separate and stand proud.
* Brownish covert feathers with dark centers.
* L-b D has longer tarsals, useful when alongside S-Ds on flat surface together.
* Even gray wash on neck and chest.
* Primaries slightly shorter than tail feathers
* Black bars wider than white bars across tail feathers.
* White eye-crescents brighter, thicker, than with S-b Ds.
* Call a higher pitched ‘keek!’
* Wide, usually dull greenish bill-base.
* Bill kinks downwards at outer two thirds of length evenly with slightly bulbous tip.
* Only S-b D has bill shorter than 1:1.3 x head length.
* More obtuse loral angle than L-b D. (Steeper forehead.)
* Supercilium is crescent-shaped.
* Dark triangle on head has concave sides.
* Larger pale patch on chin than L-b D
* Overall shape less rounded than L-b D
* Covert feathers gray with hint of brown.
* Legs shorter than L-b D, visible when on flat surface
* Specked chest
* Primaries extend slightly beyond tail feathers
* White bars wider than black bars across tail feathers.
* White eye-crescents less prominent than with L-b Ds
* Call a mellow ‘tututu!’
Normal flippant service will be resumed asap.
Thanks again to Peter and Duncan.