Breed, and thoughts on boy vs girl

[westmittengirl]

Couple questions. My dad inherited a couple of ducklings from a coworker. His son got them from TSC and said they were rouens. We have 4 rouens currently of various ages but the one looks a little different. Is it a different breed or just a variation? (First 2 pics)

So far, my rouens have all been females, I’m thinking I might have gotten my first drake. His call is softer than the others and his beak has more of a orange/green color. When the light hits his head I think I see a green tint (maybe I’m hoping). I’ve included a couple pics although not the best. They are outside with 2khakis. Thanks in advance for any thoughts!

 

[Miss Lydia]

The one duckling looks to be a Black Swedish
Pretty ducks too young to tell sex.

 

[westmittengirl]

Thank you. I googled that breed as I am not familiar with it and I can definitely see that as a possibility.