Asian waders on passage

I visited Khok Kham this morning to see what waders I could find.

Visiting the mangrove research station/visitor's centre first I found that there was still enough exposed mud, ahead of the rising tide, to offer the birds some foraging opportunities. However most of them moved off before I maanged to count them, leaving a group of 36 Whimbrel as the main attraction.

Heading back to the saltpans I failed to find any really significant concentrations of birds, but stuck around for a few hours after high tide and ended up with a reasonable tally:

Great Knot 93 (only one in breeding pluamge)
Red Knot 3 (all in adults in worn breeding plumage)
Broad-billed Sand 4 (all in adults in worn breeding plumage)
Whimbrel 36
Wood Sand 1
Little Stint 1 (adult in worn breeding plumage) 
Long-toed Stint 1 (adult in worn breeding plumage)  
RN Stint 50+
Greater Sandplover 1
Lesser Sandplover 200-300
Black-tailed Godwit 30+
Redshank 100+
Greenshank 10

Adult Little Stint

I spent a long time watching this rather worn adult Little Stint, as much as anything trying to convince myself it wasn't one, but as the pictures demonstrate, it obviously is!  Curiously it was the only summer plumaged stint that I saw today.  

male Lesser Sandplover

moulting adult Broad-billed Sandpiper

Red Knot

moulting adult Curlew Sandpiper

 

Red-necked Stint

Red-necked Stint (1st summer?)

I was struck by the difference in ground colour between the two Red-necked Stints above, with the first bird being a classic winter plumaged grey, whilst the second bird is much browner (the difference was apparent in the field when watching the two of them feeding in close proximity to one another).  The second bird is also portrayed in the two images below. My suspicion is that this second bird is a 1st summer (2nd calendar year) because the plumage looks a bit worn - if it was an adult RnS it would probably show some rufous in the neck, or on the upperparts, but if it had moulted to winter plumage it would look greyer and fresher, furthermore the breast appears more streaked that in the first bird (making me wonder if this could actually be a Little Stint, but the exposed tibia looks rather short, like a RnS). I've not found much literature describing what a 2nd calendar year RnS looks like in mid-late summer, Beaman and Madge (1998) remark of 1st summer Red-necked Stint: "rather variable, with some resembling adult winter and others adult summer. A few look similar to adult summer Semipalmated [Sandpiper], but show little or no dark streaking on lower face, neck and upper breast, and often have some rufous on head and scapulars".