Originally Posted by JonMBailey

-Scaup Ducks, Lesser and Greater
-Barrow's Goldeneye Hens from Scaup Hens
-Pintail Hens
-Widgeon Hens
-Blacktail Deer from Coastal Deer
-The Grouse and especially the Ptarmigans
-Timber Wolves from Gray Wolves

Male birds and waterfowl are often easier to recognize than females.