Black Kites have taken up hunting shorebirds at Mai Po, although they are certainly not expert hunters like peregrines. There are reports of them catching Black-tailed Godwits and Avocets, so it seems they can take on reasonable size prey. This is probably the reason that the shorebirds (especially medium-large species) are now generally quite easily flushed when they see a kite.
There has been a pair of kites nesting near the reserve for the past two years, and these seem to be the birds responsible for chasing shorebirds. I wonder whether active hunting is commoner among breeding kites, when there is an increased pressure to find food for growing chicks?