Ducklings

I checked the ducks on the dyke yesterday and counted 8,down 2 from the first count and our neighbour rang me later to give me the same news ,so it's either a predator ,or a couple of wreaklings not able to survive,there is a large barn owl flying up and down the dyke so that could be the culprit,I shall do a recount later and hope it stays at 8.