i have 4 ducks - 2 rouen claires and 2 welsh harlequins (2 males, 2 females). they are over a year old. i went in the cage this morning and one of the welsh harlequins (the female) was missing a lot of her wing feathers. her wing bones are exposed. the feathers are all over the cage. i am not sure what to think. any ideas/advice? this is our first duck illness and i wasn't able to find much online. should i separate her from the other ducks? thanks for any information you can offer.