The Helm guide (Vinicombe et al, p102) says that on average sinensis is smaller than carbo. But that the only reliable difference between the subspecies is that on sinensis the rear edge of the yellow bare skin drops vertically from the gape, while on carbo this slopes forward; I think the photos show this feature, though I'm prepared to be contradicted!
Typically sinensis is the inland cormorant, while carbo is the coastal one. This difference is mostly irrelevent with a single bird, but the fact that it was on a canal possibly adds support to this bird being sinensis.
(I'm sorry I only had a 10x zoom with me when I took these - and yesterday's - photos).
2 comments:
Hi Peter
Long time no see. In fact, these days, there's lots of carbo breeding inland apparently and some mixed colonies with birds with intermediate grape lines but above a certain angle it's sinensis as you say. I used to see both races in huddersfield. No one was that interested. See m garner frontiers book. Strange it's so approachable. Ill?
Mick
Thanks very much Mick. Peter
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