MEANS A LOT IN NATURE
by Whit Gibbons
July 1, 2007
is the Fourth of July? For most Americans, red, white, and blue. Halloween
is orange and black. Valentine's Day is pink, or red. Color is an important
component of our lives and is a defining part of the lives of many plants
and animals that tells an environmental story.
is a common characteristic of animals whose lifestyles require that they
not be easily seen. The spotted coats of adult leopards and baby deer
help them hide from the eyes of other animals, prey in the case of leopards,
predators in the case of fawns. Although their reasons for having spots
are different, both are clearly custom-made for blending into particular
habitats. Numerous examples exist for which the environment dictates the
color pattern, whether for protection of a prey species or for stealth
in a predator.
a common feature among birds, most of which can see color, for purposes
of breeding. Male goldfinches turn bright yellow and male indigo buntings
turn bright blue in the spring during the mating season. Redwing blackbird
males display bright red and yellow epaulets on their wings. The females
of the latter two species are an unimaginative brown, and the female goldfinch
is a much paler yellow than the male.
are also distinctive in their color differences between the sexes. The
brilliantly colored darters of the southeastern streams are dramatic in
their contrast between males and females. In the male Christmas darter
of Georgia and South Carolina, bright red and green bars are present during
the breeding season. Males of the redband darter of Tennessee sport bright
blue and red orange on their fins. Female darters are generally drabber
the color of most mammals is restricted to whites, browns, grays, and
black, suggesting that color blindness is a common trait within the group.
Some or all of the higher primates, which would include humans and baboons,
can see colors. The brightly colored rump region of male baboons is the
most obvious display of color among the mammals, except for hair color
among some of today's teenagers.
use color to great advantage, the various forms of color advertising being
the most apparent. Brightly colored flowers attract insects that are essential
for pollination in some species. And 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 assure that the enclosed seed will later
be deposited in another area.
also used as a lure in some species of animals. Baby copperheads and cottonmouths
have bright yellow tails that are waved enticingly in the presence of
small frogs or lizards. Because the rest of the snake is well camouflaged
in dead leaves, the frog or lizard becomes prey when focusing its attention
on the tail and mistaking it for something to eat.
are a special use of color for defense among some animals. For example,
the gray treefrog is a perfectly camouflaged creature when sitting on
an oak tree or other drab background. When a gray treefrog is pursued
by a bird that intends to make a meal of it, the frog jumps and displays
bright yellow underparts. Upon landing on a tree and tucking in its legs,
the frog blends into the background. The bird, meanwhile, is in search
of something yellow that cannot be found.
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 itself. An albino
is incapable of producing the pigments that normally give color to hair,
skin, feathers, and other surface tissues. Because of this abnormal condition,
survival in the wild is a difficult struggle.
laboratory white rats and mice are the most successful and plentiful albinos
in the world. They serve to demonstrate how human intervention in the
natural world can have an enormous impact on what constitutes success
in a particular environment.
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