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Natural Differences

Sep 25, 2018

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.

In Vivid Color

  • Male wood ducks’ plumage is very beautiful, with chestnut, tan, green, red, and white. The brownish female has a distinguishing white eye ring that tapers to a point behind the eye. Males in late summer molt to an “eclipse” plumage that resembles the female’s plumage but with more white on the chin, cheeks, and throat.
  • Adult male broad-headed skinks are usually olive brown with few or no stripes along the side, but during breeding season they develop an orange-red swollen head. Adult females nearly always have light and dark stripes down the back and sides, with a wide, dark stripe down each side being particularly prominent. Hatchlings are jet black with five narrow yellow lines along the back and sides, with a bright blue tail
  • Adult male mallards are easily identified by their green head, chestnut breast, gray body, black back, and white-bordered blue speculum, which is the wing patch located on the secondary feathers. The females are brownish with an orange bill with dark saddle markings. Male vocalizations include a loud "graeb-graeb" or a whistle.

Discover more about Missouri wildlife in our Field Guide.

Elk Tour - AskMDC

A self-guided auto tour in southeast Missouri provides the opportunity to possibly see elk bugling in the wild.
A self-guided auto tour in southeast Missouri provides the opportunity to possibly see elk bugling in the wild.

wood ducks.jpg

wood ducks
wood ducks
MDC’s annual Wood Duck Nest Box Day at Eagle Bluffs Conservation Area provides opportunity to work with experts and learn how to provide quality brood-rearing habitat. Shown here is a female wood duck with her brood.

Collared Lizard

Collared Lizard
Collared Lizard

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