We have a year old male Mallard drake who has a fixation on one of our Buff Orphington hens. There is the Mallard drake and hen, plus four chickens that were all purchased at the same time. I raised them together and handle them every day. They are all very friendly, healthy, peaceful, and freerange together on about four acres. They are locked in a 10X10 coup at night for their safety and fed a well-rounded diet. The drake has progressively become possessive over the Buff hen (who is the lowest in the pecking order) and tries to breed her literally every time he sees her. He will even catch sight of her 100 yards away and run as fast as he can to reach her. The feathers on her neck are missing now. He still breeds the Mallard female, and they are obviously paired together (they're never apart), but he will not leave the Buff hen alone. She spends a good part of the day avoiding him. I locked her up for about a week for a rest in the coup because she gave us a blood-covered egg one day after we saw him on top of her (maybe he achieved penetration...we don't know) and didn't really want to go far. Of course he spent half the day walking back and forth around the coup and quacking at her. I was wondering if any of you had any advice on how to deal with this and if there is anything we can do to help her or lessen his obsession with her? Purchasing more Mallard females at the time isn't an option, but we plan to eventually. I know he should have more than one female to him in his flock. He's a great pet duck otherwise and is not mean. I just wondered if any of you have dealt with anything like this before, why is he doing this with the specific hen, and is there anything we can do? Thank you in advance.