COLOR MEANS A LOT TO WILDLIFE

by Whit Gibbons

May 9, 2010

Colors can be powerful symbols. For most U.S. citizens, the words "red, white, and blue" conjure up flag, Uncle Sam, the Fourth of July, or some other icon of our country. "Red and green" may bring to mind Christmas. Halloween is associated with "orange and black." Only human beings are aware of such symbolism, but colors affect the lives of many plants and animals.

Among birds, most of which can see a wide color spectrum, color is a common feature for breeding purposes. Male goldfinches during the mating season are bright yellow. Male red-winged blackbirds are constantly displaying the bright red and yellow epaulets hidden beneath their black wing feathers. The females of both species are drab by comparison. The bright colors, which help males attract mates, are important for successful reproduction in these and other bird species.

Many fishes, such as the small but brilliantly colored darters of southeastern streams, also sport distinctive color differences between the sexes during spring breeding. Male Warrior darters, Tallapoosa darters, and Coastal Plain darters in Alabama are beautiful creatures with combinations of red, yellow, orange, and green. The pale females are generally yellowish and brownish.

Interestingly, in most mammals color is restricted to whites, browns, grays, and black. The brightly colored rump region of male baboons is the most obvious display of color among mammals, except for hair color among some of today's teenagers and celebrities.

Plants also use color to great advantage, particularly for advertising. Some brightly colored flowers attract insects that are essential for pollination. Few plants can be accused of false advertising as the insect lured to a flower is usually treated to nectar. Bright red or yellow berries that attract birds such as cedar waxwings offer a meal for the bird and ensure that the enclosed seed will later be deposited in another area.

Many animals use color not to attract attention but to avoid it. Camouflage is a common characteristic of animals whose lifestyles require that they be difficult to see. The spotted coats of adult leopards and baby deer help them hide from the eyes of other animals--from prey in the first case, from predators in the second. Although the reason for the spots is quite different, both are clearly adapted to blend into particular habitats. Numerous examples exist for which the environment dictates the color pattern, whether for protection in a prey species or for secrecy in a predator.

The power of camouflage among our native wildlife is readily seen in a gray treefrog sitting on an oak tree or other drab background. A biological phenomenon known as flash coloration adds an intriguing defense feature for some frogs and other animals. When a gray treefrog, which is truly unimpressive in color, is pursued by a bird that intends to make a meal of it, the frog jumps, displaying bright yellow underparts. Upon landing on a tree and tucking in its legs, the frog blends back into its background. The bird, meanwhile, has been startled and missed the frog. Upon recovering its dignity, the bird goes in search of something yellow that cannot be found because the gray frog is lying flat against the gray bark of the tree.

One color phenomenon, albinism, is not a product of the natural environment of plants and animals. Albinism is the expression of a genetic condition that can be inherited, although neither parent need be an albino. An albino is incapable of producing the pigments that normally give color to hair, skin, feathers, and other surface tissues. Plants can also be albinos. But survival in the wild is virtually impossible for an albino plant and is difficult for most albino animals.

Color is critical to the survival and propagation of the majority of animals and plants throughout the world. And understanding the whys and wherefores of coloration in nature gives researchers insight into what is going on in the natural environment. But you don't have to be a scientist to appreciate a bright red cardinal, a yellow daffodil, or an indigo bunting.

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