Old enough to sex these 2 Muscovy ducks?

[Yardmom]

Although size and stance can be used to help with gender the sounds are going to help when their sizes are similar. The males will begin to huff. At first they will continue to make other sounds as well, but those will go away. The females can make a hiss similar to the male huffs, but they don't do that unless irritated or broody.

 

[KikiDeAnime]

Are boys usually bigger than females this young? Because the light colored one is much bigger than the dark colored one despite being the same age

 

[Canadian Wind]

Is the tail thing accurate?

Sorry, lost notifications to this!

When they're older I find it very accurate, but by then I can tell by their size. As younglings, it's a good indicator if paired with other signs.

I'm still having trouble with my 2+ month olds...

 

[fowltemptress]

Are boys usually bigger than females this young? Because the light colored one is much bigger than the dark colored one despite being the same age

I'm not sure if it's usual, but my boys are much larger than my females at a very young age. I can sex mine by size at 3 to 4 weeks old.