Some of my female cayugas tails flip up a bit, that's probably not the best way to tell. My males are larger, and have a greener sheen to their heads, also greener beaks. My males also make a low, gravelly "braa, braa" sound and the girls make more of your standard quack sound. Use the link to my blog below if you'd like to see pics of mine, that may help. Good Luck!