Last weekend (21-22 Feb), I visited Khao Yai National Park for the first time in 8 years for the annual Khao Yai Bird Census held by the BCST (Bird Conservation Society of Thailand). I was responsible for surveying around Haew Suwat Waterfall area. The morning around the car park was quite birdy. There were several phylloscopus warblers flitting around in the middle story. Most of them were Yellow-browed Warblers but at least 2 birds appeared to be Greenish-type.
Both individuals were in worn plumage. Most greater coverts were missing, leaving only 1-2 greater coverts with pale tip. The crown seemed slightly darker and duller than mantle similar to most Greenish Warblers I’ve seen in the north, but probably less greyish. If I see these birds somewhere in Chiang Mai, I’ll probably wouldn’t hesitate to identify them as Greenish Warblers.
I wasn’t sure of the identity of both birds, although people say Two-barred Warbler is the one regularly found at Khao Yai. It was only until I heard the second individual’s call that I could identify it as Two-barred Warbler. Before this, I never though I’d be able to tell the difference between Two-barred and Greenish Warbler calls, but when the bird called out, the difference was more significant than I expected. It was strikingly lower pitched than the call of Greenish Warbler which I’m familiar with in northern Thailand and sounded like the call of Eurasian Tree Sparrow as described in guide books indeed.
To accompany the post, here’s a photo of Two-barred Warbler caught and ringed by Phil Round originally posted in The Wetland Trust in Asia facebook page. Unlike the 2 individuals above, this bird is in a striking fresh plumage with neat and bold wing bars, broader than anything I’ve seen. Also note how it lacks any grey tinge on the crown with yellowish face and almost no dark smudge at the tip of lower mandible. Hope I’ll see a bird as smart as this sometimes soon.