These photos were taken during the last 2 weeks of September at Doi Angkhang, Chiang Mai. I had a pretty good time taking photos of small birds in bird waves which seemed to pass by every here and there. The commonest ones included Greenish Warbler, Yellow-browed Warbler and Marten’s Warbler. However, the number greatly reduced after about one week later as they have moved further south.
Very fresh Hume’s Leaf Warbler (ssp. mandelli); note the contrast between greyish crown and olive mantle and also only one striking greater covert bar
Tertial fringes are better seen in this photo
Another Hume’s Leaf Warbler in very fresh plumage. Also note how the bill and legs are much darker than in Yellow-browed. However, this individual has more prominent median covert bar than usual, making it look slightly more similar to Yellow-browed Warbler.
And here is the Yellow-browed Warbler, also in a very fresh plumage (I love warblers in autumn!). Note the colour of the legs and bill and also the lack of contrast between crown and mantle. Both median and greater covert bars are striking.
Martens’s Warbler (Seicercus omeiensis; formerly Omei Warbler) was heard and seen regularly but getting a good photo of one was almost impossible. They moved around quickly in dark undergrowth and would fly away quickly if I got too close. The above 2 photos were my best shots. Personally, I find it impossible to identify Martens’s from Bianchi’s (S. valentini) by their appearance. You really need to hear the call to be able to identify, which is actually not a difficult task at all since they always give some calls while foraging.
Although not a migrant, but it’s always a pleasure to see this colourful little Chestnut-crowned Warbler, another seicercus found in the bird waves. Shame about the first shot, suddenly my hands became shaky and totally missed one of the best opportunities to get a decent shot of this bird…….
And the last phylloscopus to end this post with, the Claudia’s Leaf Warbler (P. claudiae). Ever since the “Blyth’s” and “White-tailed” Leaf Warblers Complex have been studied and got split into many new species, I have become much more interested in them. To our current knowledge, there are 2 species from the “Blyth’s” Complex existing in Thailand, which are the Blyth’s Leaf Warbler (P. reguloides assamensis) and Claudia’s Leaf Warbler. P. r. assamensis is understood to be resident in very few high mountains like Doi Inthanon summit area and at least Doi Chiang Dao (?), while P. claudiae is a widespread winter visitor which can be found from lowland up to at least 1,500 m (but not exceeding 1,700 m which would be the altitude range for P. r. assamensis?). The two taxon are pretty much identical plumage-wise but can be identified quite easily by their behaviours.
This photo shows a very typical feeding behaviour of P. claudiae; clinging nuthatch-like on tree trunks and branches. P. r. assamensis, on the other hand, do not show this feeding behaviour, being more like normal phylloscopus.
Here you can see the undertail pattern which is the best feature to distinguish Claudia’s and Blyth’s from the similar Davison’s Leaf Warbler from the White-tailed LW Complex. I’ll surely talk more about these 2 groups in future posts, since I’ve long been trying to take as many photos of them as possible. Claudia’s and Blyth’s have very similar undertail pattern which is the one you see here, with Blyth’s having slightly more white on the outer web.
And the last photo which shows something that I thought was interesting, the bright yellow armpit! I’ve observed this very similar feature in some other species of phylloscopus warblers as well and it seems to be found only in fresh plumage. These yellow armpits are gone once the plumage gets worn. I wonder how many species have this characteristic and what are the functions of it, probably for courtship display? Any comments and suggestions are strongly welcomed.