Mimicry in animals

Maneka Sanjay Gandhi

Mimicry, by changing form, shape and colour, is unique to animals. Imagine if you went into a Chinese or African neighbourhood and had to blend in. Or become shorter, fatter, change the shape of your nose, increase the number of arms, the odour your body emits. We can't do any of these things even if our lives depend on it.

But animals and insects do it easily. They change their forms to look like species that predators avoid. Their scents change, their colours blend in with the background or with their prey. Their ways of surviving are nothing less than magical.

The Mock Viper of  Asia is a harmless snake. It looks like a dangerous viper with a triangular head. The difference is that the mock viper has round pupils. True vipers’ pupils are vertical slits.

The Mock Viper is so clever that, when threatened, it squeezes the shape of its pupils to look like the slits of a true pit viper and then, in the panic this causes, it flees.

It's not just while protecting themselves, animals that hunt need to be clever too. Some fool their prey into believing they are harmless, while they get close to them.

The Green Lacewing larva feeds on Woolly Alder Aphids who are herded by ants. So, it plucks the white waxy wool from an aphid’s back, attaches it to its own and fools the ant shepherds into believing it is part of their flock. Once inside the circle, it eats the aphids.

The Zone Tail Hawk feeds on live animals, but it mimics the flight of a vulture who is a carrion eater. Small animals, who would have normally rushed for cover on seeing a hawk, are deceived by the gliding flight and vulture-like outline and are snatched up.

The Cleaner Fish is harmless and its function is to eat the parasites on larger fish who stand in line to be attended to. The predatory Sabre Tooth Blennny  has black and blue markings like the Cleaner and it imitates its swimming pattern and loiters at cleaning stations to dupe clients waiting to be cleaned. It comes close to large fish and bites a chunk out of them before darting away.

The Dusky Dottyback is a small 3 inch harmless looking fish which lives in our Indo Pacific coral reefs . Its normal colour varies from pink to grey,  but  it can change into any colour – green, yellow brown – to match its prey. It tricks baby fish of larger species into thinking it is one of them. Then it eats them. Its favourite prey are baby Damselfish. This unique talent allows the Dottyback to easily approach juvenile Damselfish without detection and, by the time the group is alerted, it has eaten several babies and moved to new groups of fish with new colours.

The Slender Trumpet Fish swims vertically among the soft coral branches and changes its colour to match them. It is almost invisible to the small animals that it hunts.

The Marine Flatworm increases its size to look like a Sea Slug, which is avoided by aquatic predators because it emits a poisonous and malodorous substance.

The Milk Snake is harmless, but changes itself gradually to develop bands like the venomous coral snake. Is this mimicry or a coincidence ? Definitely deliberate mimicry, because it happens only in those regions where Milk snake and Coral snake are found together. In other regions the Milk snake doesn’t look anything like the Coral snake.

Young Bushveld Lizards in Southern Africa mimic the noxious Oogpister’ beetles. As adults the lizards will camouflage themselves with the red-tan colours of the Kalahari semi-desert, but as juveniles the lizards become black and white and move with stiff, jerky movements, with backs strongly arched, to look like the Oogpister beetles who are avoided by all as they spray a pungent, acidic fluid on anyone who threatens them.

The harmless Hognosed snake, when threatened, pretends to be a rattlesnake. It raises its head as it is about to strike and makes a rattling sound from its throat. If that doesn’t work it pretends to be dead and gives off a rotting smell.

Many moths, of the families Arctiidae and Ctenuchidae, are foul-tasting and are avoided by bats who hunt by sound and  recognize their high pitched clicks. Other moths, who are edible, protect themselves as soon as they hear the bats coming by emitting the same clicks. Scientists experimented by putting out mealworms that are a favourite food of bats.  These were accompanied by recorded moth clicks. The captive bats ignored the mealworms, choosing to go hungry.

Male Photinus fireflies of North American emit pulses of light in very specific patterns when they go to find mates. The females remain on the ground and  responds to the flash pattern of  the male with her own light pattern. The flying male responds to her signal by approaching, landing, and mating.

The Photuris female firefly is a predator and eats Photinus fireflies. What she does is to copy the light signals of the Photinus female. The hapless male, after landing, is seized and eaten by the Photuris. In response to males of her own species, whom she does not eat, the female Photuris gives a flash response quite different from that of Photinus.

This one is my favourite :  The female  African mouth-breeding Cichlid fish  lays eggs and takes the eggs into her mouth immediately after they are laid, even before the male can fertilize them with his sperm. The male develops yellow, or orange, spots near the base of his anal fin, which closely resemble the eggs. He comes near the female and displays these spots.  The female thinks that she has missed out some loose eggs and attempts  pick them up in her mouth. As she opens her mouth the male release his sperm and she takes in the sperm that fertilize the eggs in her mouth.

Death’s Head Hawkmoths need honey, so they mimic the smell of bees, allowing themselves to get into hives without being stung. There, they ignore the bees, choosing to feed on the sugary honey stored inside. As soon as they leave, they resume their own odours.

The Alligator Snapping Turtle has a large set of jaws, but how does it get fish to enter its mouth ? These freshwater turtles disguise themselves among the dead wood and mud at the bottom of rivers and lakes, open their mouths and wiggle the small growth on their tongues. This growth looks and behaves like a worm. As soon as the fish takes the bait, and enters the still mouth, the jaws snap shut and the fish is dinner.

The Spider-tailed Horned Viper of Iran uses the appendage at the end of its tail in the same way. The end is a bulbous structure with thin growths jutting out of it. The structure looks like a spider. The snake moves behind rocks and raises the tip of its tail onto a rock so that birds can see it. When a bird  swoops down to capture the spider, the snake attacks.

I just read today that the Chinese Paddlefish of the Yangtze river, a 200 million year old species that survived the dinosaurs, has finally gone extinct due to overfishing and the construction of dams. It was a unique and extraordinary animal who could grow to 23 feet. It used its special sword-like snout to sense electrical activity to find its crustacean and fish prey. Again, magic. Most humans have no idea of the magical world that they destroy day after dreary, blood filled, violent day.