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Subject: is it a harrier? [Print This Page]

Author: edyip1999 Time: 8/10/2015 20:13 Subject: is it a harrier?

Taken at Gei Wei #8 in Oct 5.

Thanks for identifying as it's my first encounter of this raptor. It made almost all waders flying away and chased a pied kingfisher.

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Author: John Holmes Time: 9/10/2015 13:44 Subject: Harrier at Mai Po this week

Yes, it’s a Harrier. Harrier species are often difficult to identify.

Eastern Marsh Harrier (EMH) is our “default” Harrier, but Pied Harrier can be expected as a passage migrant in October.

Here are two shots of what I think may be the same bird, taken at Mai Po today.

An adult - or almost adult - male EMH would have a lot of white below, as seen on this bird, but should show a plain, grey tail. Females and juvenile EMH are brown and barred underneath.

Full adult male Pied Harrier is very distinctive, but the female shows

“Whitish underwing and rear underbody, greyish patches on upper primaries and a barred tail” (Viney,Phillipps and Lam, “The Birds of HK and South China”,2005).

So for me this is an adult female Pied Harrier. (But I’d welcome further comment or correction !)

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Author: ajohn Time: 9/10/2015 14:37

Interesting. I also saw this harrier today at Gei wai #8b, and I also concluded that it must be an adult female Pied Harrier. The pure white rump is another feature that does not seem to fit for Eastern Marsh Harrier.
This is not a plumage I am familiar with, and is quite different from the dark juvenile Pied Harriers that are seen more often. A very striking and beautiful bird!

Author: edyip1999 Time: 9/10/2015 16:56

Thanks for the identification

Author: wmartin Time: 4/11/2015 09:17 Subject: Female pied harrier rather than 2y male e marsh...

Late to this; found thread after discussion re photo I saw on Facebook: identified as E Marsh but to me a lot like Pied. Photographer remains adamant it's 2nd winter male Marsh. Taken 9 Oct; looks to me the same as bird here and in the thread John referenced.
Led me to do a bit of looking around online; inc finding info from Dave Bakewell - one of observers with whom I saw thousands of migrating harriers, mostly Pied, in autumn 1986 [Yikes - 3 decades ago! Sadly not so many harriers since]. After that, he was main author of short paper on eastern harrier ID; I see from his blog that can still be troublesome individuals.

During that autumn, found Pied and Eastern Marsh, especially, could be highly variable; and seemed not just with age. For instance, were some we identified as E Marsh with clean and prominent looking white rumps; only rather small proportion.

Dave's blog has photos, inc this series including male eastern marsh:

As to this one, maybe:

Pied like features include:
Barred tail [from below as well as above]; prominent dark bars on secondaries from below; obvious white rump; wings narrow even pinched at base. Bill not so hefty? - especially in shot of it perched.
Stepping back a bit, I also think overall look is right for female pied: rather earthy brown above, pale below other than darker head and upper breast streaking, without real rufous parts remaining from juvenile.
Marsh like:
Almost unbarred white/whitish primaries below; just hint of plain central tail feathers [moulting into these?], dark trailing edge to hindwing - from above and below (is it unbroken?!]

So I also reckon Pied. Those primaries perhaps of interest, tho.

I've long thought both have some sort of DNA memories of ancestral form or something like that, so occasionally individuals can be a bit like hybrids. Bit of a wild guess!

While here:
Not so remevant for HK, but we were surprised migrating Pied Harriers could often hold wings level, or even slightly downcurved, while gliding; E Marsh always shallow V that I recall/noticed. Along with forming flocks, and travelling a narrow corridor in high numbers, seems better adaptation to migration.

[ Last edited by wmartin at 4/11/2015 09:19 ]

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