查看完整版本: Asian Brown or Dark-sided?

Asian Brown or Dark-sided?

[attach]31732[/attach]Found on Old Peak Road, HK Island, 13.11.17 around 9-10am. Perched high above my head, regularly returning to same perch. Taken against the light with Fuji X-T2 and 100-400mm IS lens, handheld. I originally went for Asian Brown as the lower mandible is clearly bi-coloured but there are good arguments for this being Dark-sided.

[[i] Last edited by handrew at 13/11/2017 15:43 [/i]]

How about Grey-Streaked Flycatcher?

This is a first-winter Dark-sided Flycatcher.  It lacks pale lores and has a poorly-defined moustachial stripe and hence has the classic plain-faced and hooded appearance of Dark-sided.  The streaking below is too well defined for Asian Brown and the bill is too narrow.  There appear to be dark marks on the under-tail coverts which only Dark-sided shows.  The retained juvenile greater coverts are tipped pale buff which neither Asian Brown nor Grey-streaked show (first-winter Dark-sided does not always show this, but if present it is diagnostic of Dark-sided).  Primary projection seems long for Asian Brown.
Grey-streaked can further be eliminated as the wings/primary projection are too short, the streaks below are too diffuse and it lacks a well-defined sub-moustachial and malar stripe (which gives Grey-streaked its’ more marked head pattern).

Paul, amazing lesson in diagnostics! Many thanks. Andrew