While rounding up our birds this evening one of our mascovy ducks was trying to mate with my toulouse goose. She could not get up and her feet were straight back behind her. She tried to get up and fly but fell right back down. We got her in the house and put her in the dog kennel and after a bit she just stood in the corner. she would turn around and walk a little. after about an hour we got her out of the kennel and went to put her outside in the coop. We set her on the ground and she tried to flap her wings and she immediately fell to the ground with her legs behind her again. after about 10 minutes she stood up and went to the coop door. She was waddling strange and as soon as she got in the coop she flopped to the ground with her legs behind her again. He partner wont leave her and just hangs his head over her. I am worried that something is seriously wrong with her. I have only had birds for a year and have never had a hurt bird. any help would be greatly appreciated.