Whiskered Tern

Contributed by Doreen Ang.
This is an edited version.

AH and I, despite both being unwell, did our bit in this year's Fall Migration Bird Census held on Sunday, 10th September 2006. We decided on Lower Seletar Dam for its short route and started promptly at 7.30 a.m.

Tides: Low 0.3m at 6.54 a.m. & High 2.9m at 12.43 p.m.

It did not help at all ... we didn't mind the human and vehicle traffic but we were utterly disappointed with the dull haze.

At around 9.15-9.30 a.m., as I was scanning the mudflats through the scope, AH exclaimed, 'Tern, tern'. I obediently turned to look and this was what we saw. From the Lower Seletar Reservoir, a medium sized dark tern, larger than the Little Tern but smaller than a Gull-billed Tern, was observed flying low and parallel to Yishun Ave 1 before it flew across the road (right before our very eyes!!) and out into the sea.
From afar, its bill looked dark, however, when it made the crossing, AH positively noted the bill colour as red. I was mesmerized by the colour of its underbody. Very messy black and white mottled as if moulting from summer to winter plumage. The tern had a strong black cap and nape, very uniform grey (and not white) upperparts. Its tail was not forked.
A check with some field guides narrowed our choice of black cap/red bill down to 5 possible tern species i.e.
(1) Caspian tern - at 53cm, the Caspian is way too large.
(2) Common tern - deeply forked tail - missing in ours.
(3) White-winged tern - black head and body in summer plumage - ours had a black cap and uniform grey upperparts.
(4) Roseate tern - tail forked - missing in ours.
(5) Whiskered tern - black cap, red bill, notched tail, uniform grey top, black under-body - confirm.

p.s. The Birds of the Thai-Malay Peninsula Vol One Non-passerines by David R Wells stated that extreme early dates in autumn is 15 September in Singapore. I am sure Singapore Avifauna must have a more uptodate record, but just the same, AH and I are excited and we would like to know if we are right with its i.d. BTW, this report is at the behest of Bingwen. Guess it's payback time for making him submit the Thick-billed Spiderhunter thesis!