As Mike says, Po Toi is better located for spring migrants coming across the sea, either direct or via the Dangan Islands which catch a lot of incoming migrants. Tung Ping Chau is in the shadow of both the HK eastern coastline and particularly the Xichong peninsular.
I don't think there's much difference in autumn.
Po Toi is still only part covered, nobody at all for at least two days a week and only one ot two watchers for another three days. I estimate we miss at least half the good birds there. Still much better coverage than Tung Ping Chau though.
Haven't heard anything from Pui O recently - another good location that deserves regular watching, particularly late autumn.
[ Last edited by wgeoff at 4/10/2010 12:10 ]