These look like Little Terns to me.
A good record they are not common in autumn.
Monday 15th At Mai Po this morning . . .
Yellow Bittern - 1
Chestnut Bittern - 1 (trapped by ringing group)
Black-faced Spoonbill - 2
Black-shouldered Kite -1
Pied Harrier - 1st winter (caught and ate a Black-winged Stilt)
Forest Wagtail - 1
Black-naped Oriole - 1m
Chinese Starling - 1
Oriental Reed Warbler - 5
plus around 1,000 waders of 23 species.
Cheers
Mike K
Mike KilburnVice Chairman, HKBWSChairman, Conservation Committee