Animal Camouflage K-12 Experiments & Lesson Plans
Animal Camouflage Background
A flounder blends in with its environment.
The stripes of Plains Zebras blend together making it difficult to distinguish an individual animal.
Camouflage is the method which allows an otherwise visible organism or object to remain indiscernible from the surrounding environment. Examples include a tiger's stripes and the battledress of a modern soldier. Camouflage is a form of deception. The word camouflage comes from the French word 'camoufler' meaning 'to disguise'.
Camouflage in nature
Camouflage by its very nature is intended for animals to help avoid detection by predators
or prey. There are a number of methods of doing so. One is for the
animal to blend in with its surroundings, while another is for the
animal to disguise itself as something uninteresting or something
dangerous.
Camouflaging coloration
This is the most common form of camouflage, found to some extent in
the majority of species. The simplest way is for an animal to be of a
color similar its surroundings. Examples include the "earth tones" of deer, squirrels, or moles (to match trees or dirt), or the combination of blue skin and white underbelly of sharks (which makes them difficult to detect from both above and below). More complex patterns can be seen in animals such as flounder, moths, and frogs, among many others.
The type of camouflage a species will develop depends on several factors:
- The environment in which it lives. This is usually the most important factor.
- The physiology and behavior of an animal. Animals with fur need different camouflage than those with feathers or scales. Likewise, animals who live in groups use different camouflage techniques than those that are solitary.
- If the animal is preyed upon, then the behavior or characteristics
of its predator can influence how the camouflage develops. For example,
if the predator is color blind, then the animal will not need to match the color of its surroundings.
Animals produce colors in two ways:
- Biochromes — natural microscopic pigments that absorb certain wavelengths of light and reflect others, creating a visible color that is targeted towards its primary predator.
- Microscopic physical structures, which act like prisms to reflect and scatter light to produce a color that is different from the skin, such as the translucent fur of the Polar Bear, which actually has black skin.
Camouflage coloration can change as well. This can be due to just a
changing of the seasons, or it can be in response to more rapid
environmental changes. For example, the Arctic fox has a white coat in winter, and a brown coat in summer. Mammals and birds require a new fur coat and new set of feathers respectively, but some animals, such as cuttlefish, have deeper-level pigment cells, called chromatophores, that they can control. Other animals such as certain fish species or the nudibranch
can actually change their skin coloration by changing their diet.
However, the most well-known creature that changes color, the chameleon, usually does not do so for camouflage purposes, but instead to express its mood.
Beyond colors, skin patterns are often helpful in camouflage as well. This can be seen in common domestic pets such as tabby cats, but striping overall in other animals such as tigers and zebras
help them blend into their environment, the jungle and the grasslands
respectively. The latter two provide an interesting example, as one's
initial impression might be that their coloration does not match their
surroundings at all, but tigers' prey are usually color blind to a
certain extent such that they cannot tell the difference between orange
and green, and zebras' main predators, lions,
are color blind. In the case of zebras, the stripes also blend together
so that a herd of zebras looks like one large mass, making it difficult
for a lion to pick out any individual zebra. This same concept is used
by many striped fish species as well.
Disguise
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The camouflage technique of disguise is not as common as coloration,
but can be found throughout nature as well. Animals may disguise
themselves as something uninteresting in the hopes that their predators
will ignore them, or as something dangerous so that predators will
avoid them.
The most famous example of the former is the stick insect, which looks like a stick, as well as its cousin the leaf insect, which looks like a leaf.
Disguising oneself as something dangerous is known as mimicry, such as the case of a Scarlet Kingsnake which looks like the poisonous coral snake.
Military camouflage
A simple example of common military style camouflage.
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Camouflage was not in wide use in early warfare. 19th-century armies
tended to use bright colors and bold, impressive designs. These were
intended to daunt the enemy, attract recruits, foster unit cohesion, or
allow easier identification of units in the fog of war.
Smaller, irregular units of scouts
in the 18th century were the first to adopt colors in drab shades of
brown and green. Major armies retained their color until convinced
otherwise. The British in India in 1857 were forced by casualties to dye their red tunics to neutral tones, initially a muddy tan called khaki (from the Urdu
word for 'dusty'). White tropical uniforms were dyed by the simple
expedient of soaking them in tea. This was only a temporary measure. It
became standard in Indian service in the 1880s, but it was not until
the Second Boer War that, in 1902, the uniforms of the entire British army were standardized on this dun tone for battledress. Other armies, such as the United States, Russia, Italy, and Germany followed suit either with khaki, or with other colors more suitable for their environments.
See also
References
External links
This article is licensed under the GNU Free Documentation License. It uses material from Wikipedia Encyclopedia article "Camouflage"
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