ajohn

Some avocets in Hong Kong have paler crown/nape than others. This may be related to sex or age, but I am not entirely sure (I have seen a suggestion that adult females may be more likely to have a paler head). I agree that this bird is extreme, though, and I have not seen one as pale-headed as this. I don't see anything to indicate it is not an unusually pale Pied Avocet.