ypakwai

12/14/2008
塱原

thinfor

It shouldn't be a common hoorhen, should it?  Common moorhen is black with white under tail coverts.

It really looks like a watercock!  But can it be appeared now, as it is a summer visitor?

thinfor

Ah, my mistake...it should be really a common moorhen, winter plumage or a female?
Actually, how to differentiate this common moorhen with watercock?  Watercock is bigger but when the scale is not known... any experienced birders can teach me?  I've never seen a watercock yet.
Trying to grab a picture from the forum...

ajohn

Adult moorhen is blackish with white undertail coverts and a white stripe along the flanks. They also have a red bill with yellow tip.
The bird in this photo is a first-winter individual, which is plain brown above and whitish underneath - the white undertail and white flanks are also visible (as on adults). The brown plumage will moult into adult-type black plumage over the course of the winter.
Mai Po (especially the waterfowl collection) is a good place to get an idea of the variation in Moorhen plumage.

Watercock occurs in HK mostly as a migrant (mostly May/June and September/October). It is considerably larger than moorhen. Most birds seen here are in female/juvenile plumage, which is much more strongly marked than moorhen, with pale fringes to all feathers on the upperparts. Breeding plumage males are unusual but distinctive for being very large and all-black.

thinfor

Thank you very much for your detailed explanation, John.  That should be copied and pasted to my notes!

Should practise more to be more observant enough to see the white undertail converts (easier) and white flanks (harder) in this photo.