The person I gave the runner ducklings to that we hatched in the classroom was in today and asked me a question. He said his ducks were getting bare spots on the back of their neck. I told him it is because they have started mating. They were hatched in May of this year. He wasn't sure how many females or males he has. They have a nice little pond and then he brings them up to a pen near the house at night. I think I am right, but is there anything else that would cause that??? He is going to listen to voices and see if he can figure out how many are male and how many female.
Without actually seeing the birds - Id say you were spot on right in what you told him. Although there are some things that can contribute to feather loss- they are less likely causes due to the location. Mites or lice and poor nutrition can effect feathering - but the bald patches from mating are pretty unmistakable. It might be easier for him to find out how many girls he has by the bald necks Unless of course some of the lessor dominant males are missing a few too.
