Mimicry (zoology)

The broadest description of mimicry is when one organism, called the operator or dupe, cannot distinguish a second organism, called the mimic, from a third organism or a part of the environment, called the model. There are many different types of mimicry. Some mimics look like another organism and some smell like another organism. Some may even feel like another organism. In many ways, mimicking another organism could be helpful. Mimicry may help to hide an organism in plain sight or protect a harmless organism from predation when it mimics a harmful organism. It can even help predators sneak up on prey species when the predator mimics a harmless organism.

In the case of hiding in plain sight, the line between camouflage and mimicry is not sharply defined. Spots or stripes that help an organism blend with the surroundings are classified as camouflage since those patterns allow the organism to remain hidden in many areas with mixtures of sunlight and shadow. The organism does not look like any particular model. As an organism’s appearance begins to mimic another organism more and more closely, rather than being just a general pattern, it moves toward mimicry. As in all other areas of biology, there are arguments about where camouflage ends and mimicry begins. The stripes of a tiger and the spots on a fawn are certainly camouflage. The appearance of a stick insect is more ambiguous. Its body is very thin and elongated and is colored in shades of brown and gray. Is this mimicry of a twig or just very good camouflage? Many biologists disagree. The shapes and colors of many tropical insects, especially mantids, also fall into this gray area of either extremely good camouflage or simple mimicry.

Batesian and Müllerian Mimicry

In contrast to camouflage, which hides its bearers, many species of dangerous or unpalatable animals are brightly colored. This type of color pattern, which stands out against the background, is called warning coloration. Some examples are the black and white stripes of the skunk, the yellow and black stripes of bees and wasps, the red, black, and yellow stripes of the coral snake, and the bright orange of the monarch butterfly. Several species of harmless insects have the same yellow and black pattern that is seen on wasps. In addition to mimicking the coloration of the more dangerous insects, some harmless flies even mimic the wasps’ flying patterns or their buzzing sound. In each case, animals that have been stung by wasps or bees avoid both the stinging insects and their mimics. This mimicry of warning coloration is called Batesian mimicry. Batesian mimicry is also seen in the mimicry of the bright red color of the unpalatable red eft stage of newts by palatable salamanders.

Sometimes, two or more dangerous or unpalatable organisms look very much alike. In this case, both are acting as models and as mimics. This mimicry is called Müllerian mimicry. Müllerian mimicry is seen in monarch and viceroy butterflies. Both butterflies have many chemicals in their bodies which are found in the plants they ate as larvae. These include many unpalatable chemicals and even toxic chemicals that cause birds to vomit. If a bird eats either a monarch or a viceroy that has these chemicals, the bird usually remembers and avoids preying on either species again—a classic Müllerian mimicry. Interestingly, not all monarchs or viceroys are unpalatable. It depends on the types and concentrations of chemicals in the particular plants on which they are fed as larvae. Birds that have eaten the palatable monarchs or viceroys do not reject either monarchs or viceroys when offered them as food, but birds that have eaten an unpalatable monarch or an unpalatable viceroy avoid both palatable and unpalatable members of both species. This represents both Batesian and Müllerian mimicry at work.

Though Batesian mimicry has proven to be an effective mechanism of protection, some research has shown that it may encourage predication in the long term. When predators eat a non-toxic animal and do not become ill, they may lose their instinct to avoid specific traits that identify poisonous prey. This increases predation of the toxic species and the species that mimic it and may cause an increased death rate in the predatory species.

Aggressive Mimicry

Mimicry by predators is called aggressive mimicry. The reef fish, sometimes called the sea swallow, is a cleaner fish, and larger fish enter the sea swallow’s territory to be cleaned of parasites. The saber-toothed blenny mimics the cleaner in both appearance and precleaning behavior, but when fish come to be cleaned, the blenny instead bites off a piece of their flesh to eat. Anglerfish have small extensions on their heads that resemble worms. They use the mimic worms to lure their prey close enough to be eaten. The alligator snapping turtle’s tongue and the tips of the tails of moccasins, copperheads, and other pit vipers are also wormlike and are used as lures. Certain predatory female fireflies respond to the light flashes of males of a different species with the appropriate response of the female of that species. This lures the male closer, and when the unsuspecting male is close enough to mate, the female devours him. This mimicry is quite complex because the predatory females are able to mimic the response signals of several different species.

There are many other instances of mimicry, but the world champion mimics may be octopuses. As predators, these animals show unbelievably aggressive mimicry of other reef organisms. Octopuses can take on the color, shape, and even texture of corals, algae, and other colonial reef dwellers. As a prey species, the octopus can use the same type of mimicry for camouflage but can also be a Batesian mimic, taking on the color and shape of many of the reef’s venomous denizens.

Since, in each case, being a mimic helped the organism in some way, it is easy to understand how mimicry may have evolved. In a population where some organisms were protected by being mimics, the protected mimics were the ones most likely to mate and leave their genes for the next generation, while the unprotected organisms were less likely to breed. However,

Principal Terms

Adaptation: a phenotype that allows those organisms that have it a competitive advantage over those that do not have it

Camouflage: patterns, colors, and/or shapes that make it difficult to differentiate an organism from its surroundings

Warning Coloration: the bright colors seen on many dangerous and unpalatable organisms warn predators to stay away

Bibliography

Ancillotto, Leonardo, et al. “Bats Mimic Hymenopteran Insect Sounds to Deter Predators.” CurrentBiology, vol. 32, no. 9, 2022, pp. R408–9, doi.org/10.1016/j.cub.2022.03.052.

Brower, Lincoln P., ed. Mimicry and the Evolutionary Process. Chicago, University of Chicago Press, 1988.

Ferrari, Marco. Colors for Survival: Mimicry and Camouflage in Nature. Charlottesville, Thomasson-Grant, 1993.

Jamie, Gabriel A. “Signals, Cues and the Nature of Mimicry.” Proceedings. Biological Sciences, vol. 284, no. 1849, 2017. doi:10.1098/rspb.2016.2080.

“Mimicry in the Wild.” North Dakota Game and Fish, 2019, gf.nd.gov/wildlife-notes/mimicry-wild. Accessed 2 July 2023.

Owen, D. Camouflage and Mimicry. Chicago, University of Chicago Press, 1982.

Salvato, M. “Most Spectacular Batesian Mimicry.” In University of Florida Book of Insect Records, edited by T. J. Walker. University of Florida Department of Entomolgy and Nematology, 1999. gnv.ifas.ufl.edu/~tjw/recbk.htm.

Wickler, Wolfgang. Mimicry in Plants and Animals. New York, McGraw-Hill, 1968.