Ancona Duck Gender sign

[FenrisMau]

One of my ducks has a slight green metallic sheen on a black spot on the head... is this a sign of being a drake? They're only a month and a half old, too young to see a drake feather.

 

[JedJackson]

It's possible, but I wouldn't make up my mind just based on that. When they are 8, 9 weeks old you can tell males from females based on voice. There are several videos on Youtube that can help you do that.