Sexing blue Swedish ducks

[Gschmaltz]

I have 4 blue Swedish ducks and one really seems to quack more than the others, but I don't see a curly tail on them. Three of them look to have a slight flick/curl on the tails but nothing obvious

 

[Kevin565]

It sounds like you have 1 duck and 3 drakes.

 

[Gschmaltz]

I also have two young female chickens who aren't outside yet. If I have 1 duck hen and 3 drakes would that cause problems between the ducks and chickens living together? I