I picked out 3 Cayuga ducklings in June... and I still can't tell if they are hens/drakes!? I am a first time duck owner. They sound like males, from what I have read, but they don't have any "curled" tail feathers. 1 just started doing the head bob... possibly wanting to mate? (indicating male?) Any suggestions? Thank you! The pictures of are each individually and then all as a group.