when do they start to quack....

[kipepeo]

instead of whistle I have one girl making different sounds today they are 3 weeks old

 

[Sweetfolly]

They can start as early as 2 weeks.

 

[duckyfromoz]

I have a box of 5 four week old Pekins beside me now..And it is very clear who the girls are. I normally start hearing the difference in the voice clear enough by three weeks to be confient in saying they are female. But I always wait a little longer to determine boys to give them a chcnce to show their voices dont change later than the others.