Thanks for posting the photos. We also saw this bird yesterday in Mai Po - but only very briefly. With this set of photo, I can have second chance to look into the detail. ID on some species like this one is challenging and not very well concluded. Photo showing the feature for discussion on ID is always welcome - which give us chance to learn and refine the species ID.
It has been suggested before that the length of primaries could be used to separated Eastern Marsh and Pied - P3 in EMH is more protruded whilst P2,3,4 in PH are equal length. I tried to look at this feature in other photos but it's quite very subtle because it largely depends on how wide the bird spread its wings... Nonetheless, it suggests the bird in this photo an Eastern Marsh Harrier.
Barred tail and shape white rump are another feature to look at. And it doesn't fit very well for Pied.
It is also suggested to look at the barred pattern on primary base and secondary. But it looks marginal for this one, for me.
So, I think it's probably a Eastern Marsh Harrier and guess it's juv. male. Also, I found it quite large in size when i saw it in the field. It can't be Pied if it's male.
[ Last edited by gary at 17/10/2010 15:02 ]
