Animal Disguise and Surprise – Background

Insects in leaf litter, birds in thickets, frogs on the pond’s edge – all around us animals are hidden in plain sight. They have evolved a myriad of different disguises in response to constant pressure from keen-eyed predators. Animals can be variously colored, patterned, or shaped to blend into their surroundings, their disguise being most effective when they remain perfectly still. While some animals are concealed by camouflage, others warn off predators with bright colors, announcing danger in the form of bad taste, smell, or poison. While avoiding being eaten is an obvious benefit of effective camouflage, the ability to go unnoticed helps predators, too. It allows them to get closer to their prey before attacking, thus increasing their chances of success. In the end, whether predator or prey, those with the best disguise or surprise increase their chances of survival so that they might pass along these important characteristics to their offspring.

Many animals avoid detection because either their color or shape creates an effective disguise. Matching color is the most common kind of disguise, where skin, feathers, or fur are colored to match elements in the environment. Some animals are the same color as their typical habitat while others are patterned so they blend in with the food they eat or habitat in which they live. These animals can practically disappear when at rest; however, any quick movement might draw the attention of a watchful predator or nervous prey.

Some animals change their color with the season to blend in with their surroundings. To get ready for winter, the snowshoe hare and short-tailed weasel’s coats change color from brown to white, making each less conspicuous when the ground is covered with snow. Even large animals can blend in with their surroundings. The white-tailed deer changes its reddish-brown summer coat to a grayish one that better matches the colors in the winter woods.

The matching coloration of many female birds keeps them hidden when they are nesting and caring for young. From camouflaged eggs to newly hatched chicks, blending in with the surroundings protects animals from potential predators.

Sometimes the shape of an animal helps it go unnoticed. Many insects are shaped to look like something unpalatable in their environment. Walking sticks look like slender twigs with branches; thorn bugs both look and act like thorns, orienting themselves lengthwise on a branch; some caterpillars look like bird droppings.

Many animals display disruptive coloration – a series of patterns, spots, or stripes that break up the outline of the animal’s body, protecting them by making their shapes hard to discern. A fawn’s white spots look like sun-dappled leaves on the forest floor so it can lie hidden while its mother is away feeding. A raccoon’s telltale round black eyes are hidden in its black eye mask, eliminating an important clue to its presence. And the matching stripes on a green frog’s legs when at rest create false contours that confuse would-be predators.

The effect of light and shadow helps many animals remain hidden. One color pattern, with a lighter underside and darker upper body, is called countershading and is especially common in birds and many aquatic animals. The animal blends in with the light sky when viewed from below and with the shaded ground when seen from above. So the light belly of a frog blends in with light on the water’s surface when seen from below, and its dark-patterned back blends in with the bottom of the pond when viewed from above. This pattern also balances the sunlight on an animal’s back and obscures the shadow below so that its side profile also blends in with its surroundings.

Some creatures have a different strategy for concealment called masking. They create a protective covering from materials that are common in their habitat. Not only does it provide camouflage, but it also provides a structure to hide inside. The larva of the caddisfly makes a home out of sand grains, small rocks, or bits of vegetation it picks up from the stream or pond bottom where it lives. Bagworm larvae hide themselves within cases made from nearby twigs and leaves. Spittlebugs hide in a self-made disguise of bubbles. These immature plant hoppers (nymphs) feed on the juices of plants. Excess sap is extruded out their abdomen and mixed with air to create a soapy foam that covers and hides them from view. In addition to concealment, the foam offers air-conditioned comfort, protection from drying out, and is thought to be distasteful to predators.

In contrast to animals with cryptic coloration, some are striking in the boldness of their colors. Bright warning coloration, like the prominent black and white coloring of a skunk, is protective because it warns others to stay away! White, yellow, red, and orange with conspicuous yet simple black markings are common warning colors. Animals sporting these colors are often bad tasting, foul smelling, poisonous, or can bite, sting, or otherwise irritate anything that might try to eat them. Potential predators learn this from experience and avoid brightly colored creatures. Insects like monarch butterflies with their brilliant orange and black wings and bumblebees with bright yellow and black striping employ this strategy for survival. Warning colors are a way for animals to advertise unpleasantness and their unsuitability as food and so avoid being hunted.

The art of disguising one’s true identity by resembling the color, shape, or behavior of another unrelated animal is a form of protection called mimicry. There are two different types of mimicry. One is Mullerian mimicry – where both animals are noxious and benefit from mutual protection. The other is Batesian; here an animal gets protection by resembling a noxious animal but is not so itself. The viceroy butterfly, whose color pattern mimics the monarch, was long thought to be a form of Batesian mimicry. Scientists recently discovered that viceroys, too, taste unpleasant, thanks to a diet of willow, so both they and monarchs employ Mullerian mimicry as protection from predators, who quickly learn to avoid their black and orange colors.

Sometimes an animal has a second line of defense it uses if discovered. Often drab-colored animals, which usually go unnoticed, have hidden markings resembling a head or eyes that can be used to divert attention away from the rest of the body. If approached, it uses flash coloration, displaying these hidden markings to surprise and distract would-be predators. These markings appear aggressive and can startle or intimidate a predator who either hesitates long enough for prey to get away or simply leaves it alone. So when an io moth senses danger, it spreads its wings and flashes the large colorful owl-like “eyes” on its underwings, startling would-be predators and allowing the moth a split second to escape.

Some animals are brightly colored to announce their presence to others of their species. The bright colors of many male birds help them be seen by others of their species when they are setting up territory and trying to attract a mate.

To be seen or not to be seen, that is the question. Many wonderful examples of camouflage and warning colors can be found among animals that live in our own backyard. Next time you are outside, see if you can find any animals hidden in plain sight. Looking for them makes for a challenging game of hide and seek!

Suggested Reading

Attenborough, David. The Trials of Life: A Natural History of Animal Behavior. London: Little, Brown and Company, 1990.

Eiseman, Charley and Noah Charney. Tracks and Sign of Insects and Other Invertebrates: A Guide to North American Species. Mechanicsburg, PA: Stackpole, 2010.

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