Animal Camouflage
By Nichole Sovey
Latest update to this document: 23 April 2003
This site is designed to teach grade 4 how and why animals camouflage.
What is Animal Camouflage?
A method of hiding itself for by making itself appear as part of its natural surroundings. In natures animals need ever advantage they can get to insure their survival. It is use to hide from predators and pray. Some animals blend in with their environment some change their camouflage to adapt to their surroundings. Some animals do not hide at all, they through predictors off by looking like something dangerous or uninteresting. This frog is hard to see because its neutral camouflage make him look like the surroundings. 
How Camouflage Works
The nature of the camouflage varies from species to species.
There are several factors that determine what sort of camouflage a species develops:
- Camouflage develops differently depending on the physiology and behavior of
an animal. For example, an animal with fur will develop a different sort of
camouflage than an animal with scales, and an animal that swims in large schools
underwater will develop different camouflage than one that swings alone through
the trees.
- An animal's environment is often the most important factor in what the
camouflage looks like. The simplest camouflage technique is for an animal to
match the "background" of its surroundings. In this case, the various elements
of the natural habitat may be referred to as the model for the
camouflage.
- Since the ultimate goal of camouflage is to hide from other animals, the
physiology and behavior of an animal's predators or prey is highly significant.
An animal will not develop any camouflage that does not help it survive, so not
all animals blend in with their environment the same way. For example, there's
no point in an animal replicating the color of its surroundings if its main
predator is color-blind.
For most animals, "blending in" is the most effective approach. You can see
this sort of camouflage everywhere. Deer, squirrels, rabbits, and many other
animals have brownish, "earth tone" colors that match the brown of the trees and
soil at the forest ground level. Sharks, dolphins and many other sea creatures
have a grayish-blue coloring, which helps them blend in with the soft light
underwater.
There are two ways in which animals produce different colors.
- Biochromes, which are microscopic, natural pigments in an animal's
body, produce colors chemically. Their chemical makeup is such that they absorb
some colors of light and reflect others. The apparent color of a pigment is a
combination of all the visible wavelengths of light that are reflected by
that pigment.
- Animals may also produce colors via microscopic physical structures.
Essentially, these structures act like prisms, refracting and scattering visible
light so that a certain combination of colors are reflected. Polar bears, for
example, actually have black skin but appear white because they have translucent
hairs. When light shines on the hairs, each hair bends it a little bit. This
bounces the light around so that some of it makes it to the surface of the skin
and the rest of it is deflected back out, producing white coloration. In some
animals, the two types of coloration are combined. For example, reptiles,
amphibians and fish with green coloration typically have a layer of skin with
yellow pigment and a layer of skin that scatters light to reflect a blue color.
Combined, these layers of skin produce green.
Both physical and chemical coloration is determined genetically; they are
passed on from parent to offspring. A species develops camouflage coloration
gradually, through the process of natural selection. In the wild, an
individual animal that more closely matches its surroundings is more likely to
be overlooked by predators, and so lives longer. Consequently, the animal that
matches its surroundings is more likely to produce offspring than an animal that
does not match. The camouflager's offspring will likely inherit the same
coloration, and they will also live long enough to pass it on. In this way, the
species as a whole develops ideal coloration for survival in their environment.
The means of coloration depends on an animal's physiology. In most
mammals, the camouflage coloration is in the fur, since this is the
outermost layer of the body. In reptiles, amphibians and fish, it is in the
scales; in birds it is in the feathers; and in insects it is part
of the exoskeleton. The actual structure of the outer covering may also
evolve to create better camouflage. In squirrels, for example, the fur is fairly
rough and uneven, so it resembles the texture of tree bark. Many insects have a
shell that replicates the smooth texture of leaves.
Changing Colors
Some animals can change their colors to adapt to the surrounding around them. Usually this is due to changes in the seasons. In the spring and summer, a mammal's habitat might be full of greens and browns, while in the fall and winter, everything can be covered with snow. While brown coloration is perfect for a summer wooded environment, it makes an animal an easy target against a white background. Many birds and mammals deal with this by producing different colors of fur or feathers depending on the time of year. In most cases, either changing amounts of daylight or shifts in temperature trigger a hormonal reaction in the animal that causes it to produce different biochromes.
ARTIC FOX
Tricky Protection
As mentioned earlier some animals do not hide at all. These animal trick their predictors into think they are something else or something uninteresting.
These are the wings of a butterfly. Predators think they are looking at two big eyes and stay away.
Favorite/useful Links
Links
Link to Northern Michigan University
N Sovey: nsovey@nmu.edu