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dark-sided vs grey streaked flycatcher

Is there an easy way to tell if this is a grey-streaked or a dark-sided flycatcher?  Lamma cable road October 7th 2015
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[[i] Last edited by sgeoff at 7/10/2015 11:38 [/i]]

On first glance, it looks like dark-sided.  But after adjusting the exposure of the photo, it looks like an immature grey-streaked.
Interesting.  Would like to hear from the experts.

[[i] Last edited by irsychan at 8/10/2015 08:43 [/i]]

It looks like a juvenile Dark-sided to me.
- The underparts appear to be mottled with dark, rather than showing defined streaks
- The bill looks relatively short, and mostly dark
- The eye-ring broadens behind the eye
- White spots on the upperparts are remaining juvenile plumage. Dark-sided are most often seen in Hong Kong as juveniles, whereas juvenile Grey-streaked seems to be less common (most presumably moult before migrating).

Compare these two juvenile/first winter birds:
Dark-sided: [url]http://orientalbirdimages.org/search.php?p=55&Bird_ID=2708&Bird_Family_ID=&pagesize=1&Location=[/url]
Grey-streaked: [url]http://orientalbirdimages.org/search.php?p=17&Bird_ID=2700&Bird_Family_ID=&pagesize=1&Location=[/url]

For me, Grey-streaked usually looks somehow larger and more powerful compared to similar flycatchers, whereas Dark-sided somehow seems a little smaller and more delicate.

That was my feeling for similar reasons but I don't have experience of this species so it's nice to have some confirmation from others who have more knowledge of the species in question.  Many thanks.

[quote]Original posted by [i]ajohn[/i] at 8/10/2015 15:18 [url=http://www.hkbws.org.hk/BBS/redirect.php?goto=findpost&pid=71823&ptid=23821][img]http://www.hkbws.org.hk/BBS/images/common/back.gif[/img][/url]
It looks like a juvenile Dark-sided to me.
- The underparts appear to be mottled with dark, rather than showing defined streaks
- The bill looks relatively short, and mostly dark
- The eye-ring broad ... [/quote]

I agree with your excellent assessment that this is a first-winter Dark-sided flycatcher.  I just found a paper entitled "Brown, Siberian and Grey-streaked Flycatchers: identification and ageing" by Paul J. Leader (British Birds 103. November 2010), which gives detailed discussion on the differences between Asian Brown, Dark-sided and Grey-streaked, covering both adults and juveniles.  The section on 'Wing shape and primary projection' and Fig. 2 are particularly helpful in further supporting that this is Dark-sided.

Thanks for the reference - it's also free to download, so that's a great resource.