Call duck sexing

[meduaz]

I recently purchased 4 ducklings. There were many random sized ducklings in the litter so we picked 2 smaller ones and 2 bigger ones. The lady we bought them from said little ones are a few weeks younger than the bigger and that the breed is Call ducks. How do I sex them? They should be 4 and 6-7weeks now

 

[chickens really]

I recently purchased 4 ducklings. There were many random sized ducklings in the litter so we picked 2 smaller ones and 2 bigger ones. The lady we bought them from said little ones are a few weeks younger than the bigger and that the breed is Call ducks. How do I sex them? They should be 4 and 6-7weeks

Once they start quacking. Females are the ones that Quack. Drakes have a raspy voice.