Mine also had a brown head. I knew it was a drake by the voice and curled tail and behavior for sure. I had to rehome it because it was too hard on my Hens. I traded it for a hen Khaki and it's mate was happy as could be to have another Khaki in the pen with it. Funny how they like to socialize with their own kind sometimes.So I love my khakis they are some of the best egg layers. 300 eggs a year. Also there drakes don't always get a green head. Mine is brown. Depends on the hatcheries mating ducks. Enjoy them they are kiddish little ducks!