Gender/color/genetics question HELP!

[flynntheduck]

I have a question, I can add pics tomorrow, I have 3 runner mixes, they are siblings with black runner mom and khaki campbell dad. I have a black male, a brown female for sure and a brown of questionable gender. It is a chocolate brown but not a solid color (looks how a female mallard looks, different shades of brown) it's beak is green and feet are a yellowish brown. It does not have a loud girl quack but chatters like a girl but it is raspy. I am wondering what sex it might be? I don't know how the coloring works as far as genetics go but somewhere I read if you bread a brown male to black female all the girls will be brown and all boys will be black? Any truth to that? Or is that a crock of duck poo? I do not want any males so I need to get this figured out soon so they can go to their new home. I obviously don't want to prematurely get rid of them to later find out it is a girl. Thoughts?

 

[flynntheduck]

Anyone know?

 

[flynntheduck]

Oh yeah, forgot to mention that at 1 day old I vent sexed them and both brown ducks showed girl and black duck showed boy. However I know it may not be totally accurate for a first timer.

 

[flynntheduck]

dark brown middle one

again, middle one

Left duck is the mystery (ignore the photobombing chicken) Black one is a boy light brown is a girl, what is my mystery dark brown?!?! HELP!

 

[farm316]

The dark brown duck in the middle is a MALE! How do I know, the yellowish bill gives it away, low raspy sounds point to a male.

 

[flynntheduck]

The dark brown duck in the middle is a MALE! How do I know, the yellowish bill gives it away, low raspy sounds point to a male.

That is what I am leaning toward. But that duck is VERY chatty like my female buff. Plus what I read about the colors and genetics. But I do not know if that was correct info. He/she acts female but looks male. :/ they are 11 weeks I think.

 

[flynntheduck]

Well yep it's got to be a boy. My older drake is attacking both runner boys but not the girl. Anyone want some drakes? Ugh.