why are my ducks......

[Kool Aid Queen]

picking on my roosters i have been watching them the past few days ....
they have been in there fenced in area all winter
so this past week because it is nice here i have been letting them free range all over the yard
and i noticed they were picking on one of my roos now it looks like they are picking on a 3 big roos the lil one
has been staying near the coop think it is to wet and muddy for him

any ways why would they be chacing them???

thanks for any help i get ... and how do i stop them from doing it??

 

[BellLisamo]

my ducks started that when it was breeding season.... are yours breeding?

 

[Kool Aid Queen]

have not seen them try anything with our girl but we have a dozen eggs from her already ......so mabey .. will it stop after the breeding season is done??