Three Welsh girls

These three birds are the Welsh Harlequin ducklings we hatched a couple of months ago. One of them is darker than the others and we had been assuming that that one was female and the other two were drakes. We have now started to question this. We've not kept Welsh Harlequins before so we are on something of a learning curve but our attempts at working out which one is which sex is based on our experience of keeping khaki campbells. Having now looked up Welsh Harlequins on Wikipedia, we may now be facing a situation in which all three are ducks. The bills turns out to be the giveaway. Ducks' bills are black, drakes are yellow. And as you can see, all three have black bills. This may mean we have to incubate more eggs so that we have a drake to be able to start a breeding group. The Welsh Harlequin is on the rare breed list so increasing their numbers is important.