Mimicry

In evolutionary biology, mimicry is when one organism evolves to look or act like something else. This can happen between different species or even within the same species. One common type is called Batesian mimicry, where a harmless animal, like a hoverfly, looks like a harmful one, such as a wasp. This tricks predators, like birds, into leaving the mimic alone because they fear the model.

Many insects including hoverflies (C, D, E) and the wasp beetle (F) are Batesian mimics of stinging wasps (A, B), which are Müllerian mimics of each other.

Mimicry isn’t always deceptive. In Müllerian mimicry, harmful animals, like different kinds of wasps and bees, all look similar as a warning to predators. This honest signal helps both the mimic and the model stay safe.

There are even more interesting forms of mimicry. In aggressive mimicry, a predator might look like its prey to get closer without being noticed. In nature, we also see mimicry in plants. For example, in Pouyannian mimicry, an orchid flower looks like a female bee to trick male bees into trying to mate with it. This helps the flower move its pollen. In automimicry, an animal might mimic part of itself, like a butterfly with eye spots on its wings to confuse predators. Mimicry shows how clever and adaptable life can be.

Etymology

The word mimicry has been used since 1637. It comes from a Greek word meaning "imitative." Early scientists who studied insects first used the term in the year 1823 to describe how some animals copy others.

History

Ancient

Aristotle wrote in his History of Animals that partridges use a clever trick to protect their young. When a person comes near the baby birds, the mother bird acts as if it is hurt and leads the person away, giving her babies time to fly to safety.

19th century

In 1879, Fritz Müller created the first mathematical model of mimicry to explain why distasteful species should evolve similar appearances.

In 1817, two scientists named William Kirby and William Spence first used the word "mimicry" to describe how some insects look like objects in nature, such as tree bark or leaves.

Later, a scientist named Henry Walter Bates studied butterflies in the Amazon rainforest. He discovered that some harmless butterflies look like other butterflies that taste bad to birds. This helps protect them from being eaten. This type of mimicry is called Batesian mimicry.

Another scientist, Fritz Müller, also studied butterflies in the Amazon. He found that sometimes two different kinds of bad-tasting butterflies look very similar to each other. This helps both kinds stay safe because birds learn to avoid them. This is called Müllerian mimicry.

Overview

Evolved resemblance

Mimicry is when one living thing looks like another, often to stay safe. This can happen between different kinds of animals or even within the same kind. For example, some harmless insects might look like dangerous ones to keep away predators. There are three important parts in mimicry: the mimic, the model (the one being copied), and the dupe (the one being fooled). Mimicry can use any sense, like sight, sound, or even smell. It can help both animals involved, or just one, depending on the situation. Over time, animals that are safe to eat might start looking like ones that are not, to avoid being eaten.

Some animals change how they look at different stages of life, or even look like different things at different times. Mimicry isn’t just for insects; many other animals, plants, and even fungi can use it too. Sometimes, animals might look like everyday objects, like leaves or sticks, to hide better. This is called masquerade. In other cases, predators might look like something harmless to get closer to their prey.

Types

There are many kinds of mimicry in nature. Scientists study how these types work by looking at what helps the mimic, like staying safe from danger. Sometimes, a mimic can fit into more than one type. For example, two types might describe how the mimic and model are related, or what the mimic gains, like finding food. The names for these types have changed over time as scientists try to make them clearer.

Types of mimicry proposed by G. Pasteur, 1982
Name	No. of spp.	Function	Dupe finds Model	Deception	Description (mimic, model, dupe)
Aristotelian	2	Protective	Agreeable	Deceptive	Brooding bird mimics itself with broken wing, luring predator away from nest
Automimicry	1 or 2	Protective	Agreeable	Deceptive	Multiple forms, e.g. one sex mimics the other, tail mimics head, etc.
Bakerian	2	Reproductive	Forbidding	Deceptive	Female flower resembles male flower, cheating pollinator
Batesian	3	Protective	Forbidding	Deceptive	Palatable mimic resembles distasteful model, deceives dupe
Browerian	2	Protective	Forbidding	Deceptive	Palatable butterfly resembles toxic member of same species
Emsleyan	3	Protective	Forbidding	Deceptive	Deadly snake resembles less deadly species, predators get chance to learn to avoid them
Gilbertian	2	Protective	Forbidding	Deceptive	Host/prey mimics and so repels parasite/predator
Kirbyan	2	Aggressive	Agreeable	Deceptive	Brood parasite adult or egg mimics host which raises the young as its own
Müllerian	3 or more	Protective	Forbidding	Honest	Distasteful co-mimics resemble each other, aposematically warning off predators
Pouyannian	2	Reproductive	Agreeable	Deceptive	Plant mimic resembles female bee, deceives male, gets itself pollinated
Vavilovian	3	Reproductive	Agreeable	Deceptive	Mimic resembles crop, deceives farmer
Wasmannian	2	Commensalist	Agreeable	Deceptive	Mimic resembles and deceives ant, lives in ant nest
Wicklerian	2	Aggressive	Agreeable	Deceptive	Predator or parasite resembles and attacks prey or host; parasite may get itself swallowed
Camouflage	2	Protective	Uninteresting	Deceptive	Mimic resembles background (plant parts, or inanimate)

Defensive

Main article: Batesian mimicry

Macroxiphus, a harmless bush cricket, mimics a well-defended ant.

Mimicry can help animals stay safe by looking like something else that might scare away enemies. In Batesian mimicry, an animal looks like another animal that is not nice to eat, but the mimic itself is safe to eat. For example, some butterflies look like other butterflies that taste bad to predators. This helps the mimic stay safe because predators learn to avoid the bad-tasting butterflies and might also avoid the mimics.

Main article: Müllerian mimicry

In Müllerian mimicry, two or more animals that are all bad to eat share similar warning signs, like bright colors. This helps predators learn to avoid them all more easily. Both the animals and the predators benefit because the predators won’t waste time trying to eat something that will hurt them.

Main article: Emsleyan mimicry

Some Passiflora flower species use Gilbertian mimicry, defending against being eaten by larvae of Heliconius butterflies with leaf stipules (not shown) that resemble the butterfly's eggs.

Sometimes, a very dangerous animal looks like a less dangerous one. This helps the dangerous animal stay safe because predators might learn to avoid the less dangerous one first. For example, some harmless snakes look like deadly coral snakes.

Further information: Ant mimicry

Eyespots of foureye butterflyfish (Chaetodon capistratus) mimic its own eyes, deflecting attacks from the vulnerable head.

In Wasmannian mimicry, an animal looks like an ant it lives near, which can help it stay safe.

Main article: Gilbertian mimicry

Gilbertian mimicry happens when a plant tricks insects into not laying eggs on it by looking like the eggs the insects would normally avoid.

Main article: Automimicry

Browerian mimicry is when an animal looks like itself in a way that confuses predators. For example, some snakes move their tails like heads to escape danger.

Aggressive

Main article: Aggressive mimicry

Two bluestreak cleaner wrasse cleaning a potato grouper, Epinephelus tukula

Aggressive mimicry is when animals look like something harmless to trick other animals. This helps them catch food or find a place to live without being noticed. For example, some spiders change their webs to look like flowers, which attracts insects that think they’ve found nectar.

Some animals mimic other animals to get close to their food. There are fish that look like cleaner fish, which usually help other fish by eating parasites. These mimic fish look very similar and perform the same movements, but instead, they bite off pieces of the other fish’s fins and swim away. Even birds can fall for tricks, like a worm that makes itself look like a tasty snack to get eaten by a bird, which is its way of moving to a new home.

Reproductive

Reproductive mimicry happens when the actions of another creature help a mimic reproduce. This often occurs in plants with flowers that look tasty but don’t give any reward. It can also happen in fireflies where one type copies another to attract mates. Other types of mimicry, like those involving seeds, bird sounds, and certain parenting behaviors, also have a role in reproduction.

Bakerian and Dodsonian

Pseudoflower created by Puccinia fungus on Arabis plant. Its mimicry deceives pollinating insects, which distribute the fungus's propagules (spermatia).

Bakerian mimicry happens when female flowers copy male flowers of the same species, tricking pollinators who expect a reward. This is common in some plants. Dodsonian mimicry is when a flower copies a different species to attract pollinators without giving nectar. This happens in some orchids that look like other flowers and are pollinated by butterflies or hummingbirds.

Kirbyan mimicry, brood parasitism

Main article: Brood parasitism

Brood parasitism, or Kirbyan mimicry, is when one species copies another to have its young raised by the other. Cuckoos, for example, lay eggs that look like the eggs of other birds, so their chicks are raised by those birds. Some butterflies trick ants into caring for their caterpillars by releasing special chemicals.

Pouyannian

Main article: Pouyannian mimicry

In Pouyannian mimicry, a flower copies a female insect to attract males, who then try to mate with the flower. This helps pollinate the flower. This is common in orchids that copy bees or wasps.

Vavilovian

Main article: Vavilovian mimicry

Vavilovian mimicry happens when weeds start to look like crops because people keep removing weeds that look different. Over time, the weeds change to look more like the crops, making them harder to separate. This type of mimicry shows how humans, without meaning to, can change plants.

Inter-sexual mimicry

Main article: Sexual mimicry

Inter-sexual mimicry happens when one sex copies the other sex to get a chance to mate. For example, some small male lizards copy the looks and behavior of females to sneak close to guarded females. In some hyenas, females have structures that make them look like males.