Last Sunday during the Fall Migration Bird Census, Kim Keang and his group picked up a Broad-billed Sandpiper and a Rufous-necked Stint at the Mandai mudflats. Both were firsts for this migration season. While both waders have distinctive features of its own to tell them apart, they have very similar body structures with the Broad-billed Sandpiper looking like a medium Stint. From a distance it can be hard to separate.
This photo was taken at Parit Jawa last September after waiting for some time for both to come close to each other for a comparison shot. Both are in their non-breeding plumage. The Rufous-necked Stint is between 14-16 cm while the Broad-billed Sandpiper is at 16-18 cm in length but the size difference is very marked in the photo.
The upperparts of the Broad-billed Sandpiper is grey all over with darker wing coverts. It is lighter grey for the RNS. Both have prominent white superciliums all the way to the back of the head, but the lateral crown strip of the BBSP gives it a split supercilium look. The length of the bills is the best ID feature to separate them. The BBSP’s bill is longer. Both look straight but the BBSP actually have a slight curve at the tip (not very visible in the photo).
Let hope we get to see and compare them at Sungei Buloh in the coming days.
Ref: A field Guide to Thailand and South-East Asia. Craig Robson. 2000.