When males of a species look different from females, it is called sexual dimorphism. Seasonal decorations can help some animals distinguish males from females. Male deer, elk and moose sport antlers part of the year. Male broadhead skinks, a kind of lizard, develop bright orange-red heads during the breeding season, and the colors of some male fish change or intensify at breeding time.
Bright colors or a flashy rack help males attract mates. But bright colors or big antlers might attract unwelcome attention to the site of helpless young. It turns out that frequently, in species where the males and females look dramatically different, the males do not help in rearing the offspring.
Among some animals, the males and females look different year-round. Male mallards have rich, dapper colors while female mallards are dull brown. Male box turtles are orange-eyed and the females are brown-eyed.
Sexual dimorphism is not limited to animals. Some plants have individuals that are distinctively male or female. In cottonwoods and willows for example, male trees bear flowers that are different in shape than the flowers on female trees.
Discover more about Missouri wildlife in our Field Guide.