Ok, so the pen is now split and i have returned the duck outside. I actually decided to put her with the male. He is the quietest and least aggressive with her. So far so good. She is eating and drinking and seemed to be ok with being out there. I guess time will tell. She just seems to be too bright and alert to be seriously ill. She has a good wind break and a house filled with straw. I appreciate every body's take on the situation. I did read one other post where almost the exact same thing was happening. Must be the time of year for raging hormones, or the severe boredom of winter.