This spring, we (well, my FIL bought them but we take care of them) picked up a number of Blue swede and Khaki ducklings. We already have two female runner ducks and a Buff drake, so right now we have a total of 12 ducks. My problem right now is actually in trying to figure out if we still have any more drakes in this group. I know that out of the 12, at least two are drakes (our Buff, and a khaki that looks like a Mallard). But how can I tell if any others are male? We are getting two eggs a day, but I am pretty sure my runners aren't laying so they would have to be from the new ducks. I have seen a few of the questionable ducks *acting* like males, by mounting some of the other ducks. But is this strictly male behavior (I know it is seen in other species, so I am not positive here). One of the black colored Blue Swedes has a rather green colored head, and we assume it is male. I just can't seem to find many answers on the interwebs, and I am hoping someone here can help us out! Ultimately if they are all female (well, except for the two males we know we have), that would be awesome. I would love to try and figure this out before spring, though, and without having to separate each duck from the flock for a few days just to see if they are laying. Thanks!