Mimicry

In biology, mimicry means that two or more organisms seem similar to each other but are not connected according to their biological makeup. Because they resemble each other, one or both get protection from predators. According to most studies, the relationship between the two organs gives more benefit to one rather than both. Usually, the two parties in the mimicry relationship together deceive a third party.

In 1862, Henry Bates, an English biologist, published a paper discussing the great similarities in color of two separate Brazilian butterflies. Butterflies of one family, the Heliconiidae, are very brightly colored but cannot be eaten by birds. Those of the other family, the Pieridae, can be eaten. He believed that predators can recognize by coloration that the members of the Heliconiidae family cannot be eaten. They transfer that knowledge to the other family of butterflies. Thus, both families, including the edible kind, are protected from predators. This type of mimicry is called Batesian.

Bates also observed that several similar butterflies of different families were all inedible but looked the same. They all were protected from predators. He wondered why this was the case. A German biologist stated that he thought the reason several species looked alike although all were harmful to predators was to allow the predators to learn from one that all were dangerous. The tendency of inedible or dangerous species to look alike to protect each other is called Mullerian mimicry after Franz Muller.

In some situations, it benefits a predator to look like its prey. A predator takes on some aspects of its prey to gain the advantage of it or a third party. It may do this only during one stage of its being. For example, the eggs of a parasitic cuckoo resemble those of its host organism. This is called aggressive mimicry.

In automimicry, members of a species have an advantage because they resemble others of their species. For example, males of many bees and wasps do not have stingers. However, they closely resemble those which do have stingers. In addition, some butterflies take in poison from some plants they eat when they are larvae. Other butterflies of the same family, but a different subgroup, do not eat poisonous plants, but they are connected to the others in the minds of the predators.

Other types of mimicry are different from all those mentioned above. South American coral snakes are very poisonous. They are striped in red, black and yellow. Several types of non-poisonous or not lethal snakes have almost the exact coloring. They are called false coral snakes.

Certain chemicals in plants can protect the plants from being eaten. These can affect the heart or stimulate the brain to cause vomiting. The amount of the chemical which causes heart failure is much greater than that which may cause vomiting. Therefore, an animal which tastes just a little of the plant and vomits learns never to go back for more.

The larvae of a type of butterfly which includes the monarch butterfly eat the poison of the Asclepias milkweed. They have no bad effects from it. However, when they grow to adulthood, this poison protects them from vertebrate predators.

Sometimes predators can still break through the protected species. Bee-eater birds can eat bees with stingers because they have a horny beak which protects them from being stung. They are able to remove the stinger before they swallow the prey by wiping it on a branch.