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Subject: [Falcons] Besra - in flight [Print This Page]

Author: John Holmes Time: 2/06/2010 09:10 Subject: Besra - in flight

2010-May-14 Mai Po Access Road
ID MK IIN + 800mm (1/2500, f 5.6, ISO 400)

With thanks to John Allcock for discussion on identification !

Image Attachment: Besra_MPAR_14May_jh.JPG (2/06/2010 09:10, 135.2 KB) / Download count 544
http://hkbws.org.hk/BBS/attachment.php?aid=6728

Author: brendank Time: 3/06/2010 00:48

John-Could you comment on the key ID points? I still don't feel very comfortable identifying small accipiters I see here during the winter.

Brendan

Author: John Holmes Time: 4/06/2010 08:29 Subject: Accipiters

Hi Brendan,

I'm still not very comfortable with accipiters, either ! But here goes..

For Besra, the main confusion species would be Crested Goshawk and Japanese Sparrowhawk.
The 1994 HK Bird Report has a paper by Geoff Carey and Paul Leader where they compare Besra with Japanese Sparrowhawk and describe asian accipiter identification as "notoriously difficult" !

On this photo, the prominent gular stripe should eliminate Japanese Sparrowhawk.

The orange eyes should eliminate Crested Goshawk which is yellow-eyed. CG also has wings which are more rounded and broad with a "pinch" in near the body and fluffy white feathering around the vent.

For a female Besra, the heavy rufous barring is a good point, and the solid rufous flanks and sides of the breast are a good pointer too.

( I think Plate 52 of Mark Brazil's "Birds of East Asia" is a useful reference for accipiters here in Hong Kong.)

And there is more Besra material in this forum, of course

http://www.hkbws.org.hk/BBS/sear ... mp;searchsubmit=yes

I hope this helps.

There is always the possibility I could be mistaken on my identification, and discussion is useful !

John

Author: brendank Time: 7/06/2010 00:42

Hi John,

Thanks for the comments.

"the prominent gular stripe should eliminate Japanese Sparrowhawk"

this I didn't know and would be quite useful for seperation.

Crested Goshawks usually have a very distinctive shape in flight so in general I think they are easier to recognize. But I can't say I feel very comfortable with Japanese/Chinese/Eurasian Sparrowhawk/Besra at a distance and unfortunately we usually don't see accipiters for very long.

Brendan

Author: ajohn Time: 11/06/2010 13:58

As John mentions, he had previously shown this photo to me, and I agreed that it was a Besra. In this case, John has been lucky enough to see some of the useful plumage features. Useful features visible on this photo are the gular stripe, heavily marked underparts and plain grey cheek. These effectively eliminate all other Hong Kong accipiters except Crested Goshawk, which in plumage is similar to Besra. Unlike Crested Gos, the underwing coverts are fairly heavily marked and the undertail coverts are not particularly prominent. For a useful comparison, see Thomas's recent photos of a Crested Goshawk here: http://www.hkbws.org.hk/BBS/redi ... o=lastpost#lastpost

Of course, it is often not possible to get such good details of accipiter plumage. In this case I tend to rely on a combination of size, structure and habitat.
Crested Gos is large (females can look very large) with broad, paddle-shaped wings "pinched in" at the base and with bulging secondaries (again, compare Thomas's photos). The tail tip is rounded, which can be useful on perched birds. It is generally found in forest such as Tai Po Kau.
Besra is medium size. The wings are fairly short and broad but without the bulging secondaries and narrow base of Crested Gos. The tail is moderately long and square-tipped. It seems to be associated with smaller woodlands on the edge of open country, and seems to be the commonest accipiter at Mai Po.
Japanese Sparrowhawk is small (males can look tiny). The wings are relatively longer and more pointed than Besra. The tail is often noticeably short and square-tipped. The gular stripe is weaker or absent and the underparts are more finely barred. Habitat is similar to Besra, but Japanese occurs mostly on passage with some birds in winter.
Eurasian Sparrowhawk is moderately large (between Besra and Crested Gos). The wings and tail are both relatively long and narrow. It lacks the gular stripe, is finely barred below and has a well-marked supercilium. This species is fairly uncommon on passage and in winter, mostly in fairly open country.
Chinese Sparrowhawk is distinct, with fairly long, pointed wings and therefore sometimes looking more falcon-like. The black wingtips and plain underparts are useful plumage features. It often occurs in flocks and is widespread during passage, especially in spring (and especially this year!)

Of course, accipiters are all tricky to ID and it takes practice and field experience. I do not claim to be as expert as others in HK, and often leave birds unidentified. No doubt others can elaborate on or correct my various comments above.

Author: brendank Time: 11/06/2010 23:49

Thanks for the info!

Would I be right to call this a Chinese Goshawk?

Brendan

Image Attachment: J_sparrowhawk.JPG (11/06/2010 23:49, 121.55 KB) / Download count 419
http://hkbws.org.hk/BBS/attachment.php?aid=6781

Author: John Holmes Time: 12/06/2010 11:49 Subject: mystery raptor

Brendan,

Actually, looking at the long, thin wings and distinctive tail pattern (barred, but not right to the edge of the tail)
I'd say this was Grey-faced Buzzard.

John

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