title: Annual variation in reproductive behavior, testosterone, and plasma FSH levels in the Rouen duck, Anas platyrhynchos.
mesh_terms: D000374:Aggression; D000818:Animals; D004372:Ducks / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D008297:Male; D012726:Sexual Behavior, Animal; D012919:Social Behavior; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D005640:Follicle Stimulating Hormone