Trying to determine if my 4 mo old pekins are actually the sex i thought they were

[MAMADUKE627]

Hi, I have 15 ducks but they are penned according to age group due to aggression between males. One pen is 2 pekins, a male cayuga, and a female Indian runner/Rouen mix. At 24hrs I vent sexed all 4 and determined I had 1 male pekin and one female pekin but as they've gotten older I've gotten more unsure about the male pekin. He doesn't have a drake feather like the cayuga or the low raspy quack. But if any other males come near his partner he will attack them and my knowledge is only males are aggressive towards other males but I know there's something I'm missing especially since now I'm finding eggs in the nest and my male pekin is the one making the nest and sitting on the eggs. I'm not out with them all the time but when I am he is the only one even bothering with them except for onece both pekins were making the nest together..
What do you all think? Do I have 2 females or is it possible for a male to behave this way?

 

[HollowOfWisps]

Hi, I have 15 ducks but they are penned according to age group due to aggression between males. One pen is 2 pekins, a male cayuga, and a female Indian runner/Rouen mix. At 24hrs I vent sexed all 4 and determined I had 1 male pekin and one female pekin but as they've gotten older I've gotten more unsure about the male pekin. He doesn't have a drake feather like the cayuga or the low raspy quack. But if any other males come near his partner he will attack them and my knowledge is only males are aggressive towards other males but I know there's something I'm missing especially since now I'm finding eggs in the nest and my male pekin is the one making the nest and sitting on the eggs. I'm not out with them all the time but when I am he is the only one even bothering with them except for onece both pekins were making the nest together..
What do you all think? Do I have 2 females or is it possible for a male to behave this way?

- Pekins don't sexually mature until 6-7 months so no drake feather is not uncommon for a 4 month old pekin.

-Aggression goes both ways as drakes and hens can be aggressive for a variety of reasons, but aggression is not drake exclusive.

The best way to determine if your duck in question is a drake or hen is by voice sexing. Does it have a honky quack or has it ever let out just one loud quack? If you need to pick your duck up and see what noise it makes. Even my hens that rarely ever make a sound will usually let out a good quack when I pick them up.