Animal Behavior/Mimicry and Camouflage

Mimicry
A major concern of animals and other critters is to protect themselves from predators in order to survive and reproduce and pass their genes off to a new generation. Many animals have evolved adaptations known as anti-predator devices such as camouflage and chemical toxins. Animals use camouflage to blend in with their environments in an attempt to be unrecognizable by predators. Other organisms such as the monarch butterfly contain chemical toxins that are secreted into the predator’s mouth when it attempts to eat the butterfly. The monarch butterfly also has warning coloration that gives a warning sign to predators to remind them that the butterfly is toxic and should not be eaten.

These anti-predator devices are so successful that other organisms have been known to mimic them. The organism that is mimicked is known as the model and the third party that is deceived by the model and its mimic is known as the receiver. The mimics have learned to take advantage of the color patterns and markings that predators have learned by experience to avoid. The model is usually a species that has an abundant population and has successfully warded off predators with an anti-predator device.

Organisms have learned to mimic their surroundings or environment in an attempt to “hide” from predators. For example, lizards have learned to mimic tree trunk color which proves to be very successful as predators will simply move past them as they believe that they are simply looking at a tree. Another example of this type of mimicry can be seen with the Katydid who will mimic a leaf in both color and shape in an attempt to be hidden.

Some prey animals have evolved certain patterns on their bodies that mimic other animals in an attempt to startle their predators. The most common example of this type of mimicry can be found in some moths and butterflies who flash eye spots on their wings to predators. These eye spots startle the predator who believes that the eyes belong to a much larger animal that may be a threat to them.

In one form of mimicry known as aggressive mimicry, an organism will mimic a signal that is either deceptive or attractive to its prey. One example of this involves the praying mantis who will mimic flowers to attract insects that they can then capture and eat. Organisms can also imitate the behaviors of other organisms. Moth caterpillars, for example, will imitate the motion and body movements of a snake in order to scare off predators that are usually a prey item for snakes.

One of the most popular types of mimicry involves the warning coloration found on inedible or toxic organisms such as the monarch butterfly. Once these toxic organisms have adapted this warning coloration which warns predators to stay away, other organisms may start to mimic this warning coloration in an attempt to stay alive. Batesian mimics are those mimics that imitate unpalatable species even though they are palatable. Therefore, one species is harmful while the other is harmless. The wasp is a great example of Batesian mimicry. The wasp is the model species in this example as it possesses a sting which enables it to escape from predators. The bright warning coloration of the wasp has been mimicked by many other insects. Even though the mimics are harmless, the predator will avoid them due to bad experiences with wasps with the same coloration. With Müllerian mimicry, many unpalatable species share a similar color pattern. Müllerian mimicry proves to be successful as the predator only has to be exposed to one of the species in order to learn to stay away from all the other species with the same warning color patterns. The black and yellow striped bodies of social wasps, solitary digger wasps, and caterpillars of the cinnabar moths warn predators that the organism is inedible. This is a great example of Müllerian mimicry as all of these unpalatable, unrelated species have a shared color pattern that keeps predators away.

Mimicry is a very successful anti-predator device that species have evolved over many generations. As one can see, organisms have come to mimic many different characteristics such as color patterns and behaviors. However, selection only favors the mimics when they are less common than the model. Therefore, the fitness of mimics is “negatively frequency-dependent.”