wgeoff

I have transferred this image from the Po Toi site, I would like advice from any Cormorant experts as to whether adult Great and Temminck's can be separated in the field and what are the key things to look for. Different books mention different things.

I saw this Cormorant on a rock next to the small island just south west of Po Toi from the ferry today, Thursday 4th January. Unfortunately, it was some distance away and I only had a brief time, just enough for this photo. It was not there on the return journey. The only comment I have is the white face patch was quite large, going part way down the throat as you can see fro the photo. This is the only Cormorant I have seen in the waters around Po Toi, except for overflying migrants.



[ Last edited by wgeoff at 18/08/2010 17:28 ]

tgraham

Geoff

The identification is to do with the shape of the yellow gap. I have sent you some photos of both Great and Temmincks which highlights the differences.

Basically on Great the yellow gap goes straight down where as on Temmincks it angled.

Its hard to tell from your photo but I would er on the side of Great

If you look at the old BB there is a very good thread on how to tell the difference

HK Twitcher

wgeoff

Yes, thanks Graham.

But the gape is difficult to see at a distance. I'm wondering if there are other diagnostics for an adult bird. The 2005 bird was a juvenile.

fforrest

Below are two threads of messages in the old BBS regarding the Temminck's Cormorant.

http://www.hkbws.org.hk/cgi-bin/yabb/YaBB.pl?board=BirdingTips;action=display;num=1113903625;start=9

http://www.hkbws.org.hk/cgi-bin/yabb/YaBB.pl?board=PhotoGallery;action=display;num=1114087774;start=0

wgeoff

Thanks Forrest. I'll try to get a copy of Nial Moores paper.

wgeoff

Nial Moores writes from Korea

'Dear Geoff,

Very warm greetings from Korea.

I regret that I do not have an electronic version of that paper.
Beyond habitat, there are three or four main things to look for in non-breeding plumaged Temminck's:
1) an often clearly yellowish lower mandible, especially basally, contrasting with dark upper (I think never seen in Great): this feature is most striking in young birds;
2) more extensive yellowish bare skin, often coming up obviously around the eye, and  coming back to form more of a pointed gape line (rather rounded in sinensis types it seems);
3) More extensive white on the so-called face, often leaving the eye looking a little isolated and obvious (as in your photo);
4) Often paler upper throat.

I am attaching a large image of two immature birds taken in October (sadly could not find image of adult type in limited time i have) - you can see most of these features in evidence, shown more strongly by older birds.

Very best wishes,

Nial
Birds Korea'



So, maybe my bird was a Temminck's, from the extent of white on the face and going down the throat.

I hope to find it again and get some better photos.

[ Last edited by wgeoff at 18/08/2010 17:29 ]