hgeorge

An unidentified Phylloscopus warbler was seen in the studying garden in the morning (around 0915) and was seen again near the starting point of four-colour path around 1200.

Obviously, the warbler has a yellowish rump (not bright yellow). So many kinds of leaf warblers (no yellow rump) can be ruled out. There are only four species can be chose for.

The bird did not show gray throat and yellow belly. Ashy-throated Warbler is not the answer. Also, the bird did not show white outertail and buff wing-bar. Buff-barred Warbler is ruled out.

Hence, only four smaller size species of Pallas's Leaf Warbler, Lemon-rumped Warbler, Gansu Leaf Warbler and Chinese Leaf Warbler can be the answer. However, the bird did not fit into those species especially talking about the size of the bird I saw. Why?

Features as follows,
Overall size and impression:
longer tail and bigger size of body comparing with small size of Pallas's Leaf Warbler nearby
size and behaviour is similar to a Yellow-browed Warbler, seldom to hover, mostly searched on the branch.

Head:
an extremely thin whitish crown stripe from the forehead to the crown and suddenly broader on the nape
dark (not dull green) eyebrow and lateral crown stripe
some pattern on pale ear-coverts
creamy supercilium

Wing:
very broad yellow wing-bar (greater coverts) and thinner yellowish wing-bar (median coverts)
dark inner web greater coverts and light green on the margin
white edge of tertials
green edge of wings

Mantle, tail and underpart:
green mantle and tail
tend to bicolor on the rump, overall, yellowish rump, but tend to whitish near the direction to the tail
uppertail coverts as mantle
whitish uderpart from throat to belly
no yellowish on undertail coverts

Bare part:
pale leg
light lower (tend to yellow) mandible and dark upper mandible

Sound:
No sound was heard, so trouble

Habit:
accompanied with a big bird wave, species included Blyth’s Leaf Warbler, Goodson’s Warbler, Pallas’s Leaf Warbler, Yellow-browed Warbler, Blue-winged Minla, Rufous-capped Babbler, Streak-breasted Scimitar Babbler, White-bellied Yuhina, Yellow-cheeked Tit, Velvet-fronted Nuthatch and Grey-headed Flycatcher.

Distance from the bird:
close view (two to four meters) at first sight for three to five minutes

Light condition:
Sunny day with normal light condition

Comment form others:
My friend also saw it well. She have several experience for woodland birds and she also agreed with the bird's size was as big as a Yellow-browed Warbler and not fit into any small type of warblers she knew.

I have similar experience on all those warblers I mentioned above.

So, for my conclusion, a new species or a hybrid ???
I really don't know...................

Please give any comments on it to help me ....
Thanks ...
George

By the way, a tiny size of warbler with no yellow rump on mantle was seen on December 2007. The sound is different from all warblers in Hong Kong. I am not familiar with this strange two-note sound. Also, it was similar to the features of Pallas's Leaf Warbler but no yellow rump, so it could be White-tailed Leaf Warbler. (I heard it from Yunnan and Sichuan but forgot it already). However, no clear and close view on it in many cases.

Thanks for view ..........