Hi! I recently received 4 baby khaki Campbell's. One has a yellow stripe by it's eye and has a lighter chest. Is this a different breed of duck? Or is it a male. The rest look similar and are all khaki colored. They were sexed as female at 1 day old, but I imagine that's not fool proof. Thanks for the help! Btw they are 3-4 weeks old and beautiful. Excuse my messy duckling in the picture, they just finished a feeding frenzy.