Drake or Hen Mallard?

[Pete Tracey]

At 45 days old, they all have green to their head, but 3 are bigger than the others and 4 have a yellowish bill developing. How can I tell for certain which ones are drake or hens?
I can't tell by their quack either. They all sound the same.

 

[Pete Tracey]

Here is another pic. Which are drakes and which are hens, because I'm only certain on 2-3.

 

[TLWR]

They won't develop adult coloring for a while. In another week or so you should start being able to tell by voice.

 

[Pete Tracey]

Thank you

 

[sourland]

They won't develop adult coloring for a while. In another week or so you should start being able to tell by voice.

I agree. Welcome to BYC - your birds are in great condition.

 

[gander007]

At about 4 months color will start to show .....

 

[Pete Tracey]

Thank you kindly