Changi, SBWR, Tuas 18Sep10

From KH

We started off at Changi for the raptors and ended up with 1 migrant Japanese Sparrowhawk and the usual resident CHE, WBSE, BWK and Brahminy Kite. Non-raptors of note include a Ruddy-breasted Crake and 2 Red-whiskered Bulbuls. The only surprise here was a giant weaver nest.

At SBWR, there was nothing special except for the usual waders, though we did spot a GSP. At Tuas, we were saddened by the loss of the grassland, though it was good to know that the motorcross area is accessible. A good number of Brown Shrikes were present, so were 3 resident species of munias and a pair of BWKs.

From JS

Today, at SBWR, KH, my father and I saw all the waders sp. that were reported by LKS, minus several greater sand plover individuals. As this was the start of the fall migration, I took the opportunity to look at the transitional plumage of the common waders. The usually dull non-breeding waders looks more vibrant at this time of the year than at other times when we see them in our region.

As usual, when I keep staring at the same species of birds, I would always try to look for something new. Since all the curlew sandpipers did not have black belly and there was no stint present, I picked on the golden plovers to observe.

Below are my observations:

1) A small minority of the pgps still retain some degree of the black on it underparts.
2) Among these small minority of pgp, on first look, a few has rather long primaries that extends beyond the tail. However, I have also noted that some postures of the bird could easily deceive one to think that the bird has such a feature. With patience, I picked out two individuals that truly have such a feature.
3) On second look, both birds appear darker than the other pgps and less golden. Maybe my eyes were playing tricks on me, so I went a step further to gauge the qualitative description.
4) Both birds exhibit protruding primaries beyond the tail with the length of extension roughly the distance between the outermost primary and the 3rd visible outermost primary for each wing. This observation was aided by the rather short tertials.(slightly longer than the greater coverts)
5) Suspecting that the birds may be agp instead of pgp, I counted the exposed primaries and the total is 6. Due to the high degree of wear of the tertials, I minus 2 from the total with expectation that the degree of wear is so severe that the tertials are shortened (?).

After making my observations through the scope, I tried to photograph as many views of the bird. Unfortunately, the color reproduction ability of the camera could not match the eyes'; all the photos had yellow wash.

Back at the SBWR's library, I looked up a few guide books for additional information on the transitional plumage of the AGP and PGP. Surprisingly, there was little information on the fall migration moulting process of both species. Only very small photos were available for reference and they look like mine.

Similar features with photos of agp in "breeding to non-breeding" plumage:

1) Remnants of white breast patch (whitish patch with no obvious black blotch)
2) High degree of variability of the black on the flanks and sides
3) Remnants of black forehead
4) Development of dark eyestripe and "less prominent" ocular spot because of pale linkage to eyestripe (all the other PGPs with remnant of breeding plumage were noted to have buffish ocular spot and buffish forehead)
5) Short legs
6) Primaries extending beyond tail
7) More than 3 exposed primaries
8) Tertial fall short of tail

Individual 1

Individual 2