We just came home and one of our male adult pekin ducks( about 9 months old) was just sitting there looking sick. His head was kind of hanging there. We brought him in and he's sitting in a box holding his head normally most of the time, but if something startles him he attempts to get away. He apparently cannot walk well- although no injuries are present. After he tries to move then his head will hang like he's dying. But in a minute he'll just sit there holding it up okay again. He must have just walked up into the yard from the creek with the rest of he ducks.He did not exhibit any problems before this and nothing has changed as far as food or housing His bill feels very warm like he might have a fever and a little water is draining from the nostrils. Has anyone seen this behavior before?