I have 2 muscovy that are about 15 weeks old (HUGE) a 2 year old runner and 14 week old runner/pekin mix. Recently I noticed that the runner stopped quacking and seems depressed. She still eats/drinks/forages but instead of acting like her normal bubbly self, ignores me when I talk to her and now follows the runner/pekin around (her daughter) I've seen both my male and female muscovy biting her back and her feathers look ruffled. There is quite a bit of size difference between them and I'm thinking she is being bullied to the point of depression. She used to quack all the time and was excited when I came in the pen and now seems so sad and passive. I thought maybe she was sick at first....any thoughts??