E-Kantipur

Every year, I find myself at the annual cactus and succulents show in Delhi. This is a group of plants that is utterly beautiful and intelligent. My favourite among them are the Lithops or living stones. These plants look exactly like the pebbles that surround them in the desert. Both plants and animals use colours and shapes in a way that keeps them hidden. How does a being become invisible in plain sight, airbrushing himself out of the frame in a way? While humans stand out like sore thumbs, most animals and insects have mastered the art of standing right there but invisible.

One way is to use colour camouflage called crypsis, where their coloration makes them indiscernible from the background and undetected. Colour is used in two ways: concealing coloration and disruptive coloration. Concealing coloration is when animals use colour to conceal their presence by blending into the surroundings, matching their colour to their habitat. Plovers that feed in wet sand and muck have darker-brown backs than plover species that spend their time in dry, lighter-coloured sand dunes.

Some animals go even further, coordinating their look with the seasons, shedding dark fur like stoats who are brown in summer and white in winter or moulting dark feathers once the snow falls. The Arctic fox has a dark coat in the spring and summer to match the brown dirt in its environment. In the fall and winter, it turns white to match the surrounding snow. In the summer, an Arctic hare is brown and grey. These colours blend in with shrubs, grasses and rocks. But as the winter nears, the hare loses its dark fur and grows a snow-white coat.

Sharks, dolphins and many other sea creatures are greyish blue on top and have a white underbelly which makes it difficult to detect them from both above and below. Lizards blend their colours so well that it is impossible to spot them on logs or rocks where they bask in the sun. Stripes are useful to hide in tall grass, a tawny colour to blend in with the black, white and grey scenery. Dark fur resembling tree bark adds to the confusion of the visual senses, and just as suddenly as a creature was there, it has now vanished.

The harlequin filefish is a blue and yellow spotted fish who lives among the coral. It has found an ingenious way to avoid being gobbled up during a nap. It has evolved polka-dot markings that match its coral home. Just before a snooze, the fish slicks back its fins to look like a piece of reef. Its colour and polka-dot pattern match the pattern of polyps on the surface of the coral colonies, while the lighter colouring of the tip of its caudal fin mimics the coral’s growing tip.

Moths actually evolve to change their colouring depending on their surroundings. Their adaptation was noticed a hundred years ago in Victorian England. As buildings became dirtied from soot and pollution during the Industrial Revolution, the moths that resided there which were pale in colour gradually darkened to remain hidden in the darkening buildings. The amazing trickery of animal camouflage is to be admired. The king is, of course, the octopus who can change its hue in seconds by opening tiny colour sacs in its skin.

The boa constrictor relies on surprise to snare its snacks. Its chocolate and cream coloured scales blend with bark, soil and leaves. These contrasting colours are arranged in scattered patches like mismatching puzzle pieces. This design gives a boa’s body a disconnected look and breaks up the strangler’s shape. Prey do not detect its slinky form until it is too late. Garter snakes with their bright red, yellow and blue colourings are hard to see as the markings break up the outline of their bodies. The narrow-headed frog’s brown and yellow colouring allows it to blend in with the mud and tree trunks. Cryptic frogs have developed a colouring that is similar to the leaves found in its environment.

Many aquatic animals possess the ability to hide in plain sight. Sea creatures use camouflage for a variety of reasons: to avoid discovery by predators or keeping cover to predate on others. Some use it for their nesting areas to ensure that hatchlings from the eggs live to see the light of the sun. The scorpion fish is an adept predator, and part of this talent is because of its brilliant ability to camouflage itself. Others in areas of coral reef take on the colouring and spines of the coral. Rays and skates spend the majority

of their time on the sea floor, foraging for food and laying their eggs within the soft sands. Their skin colouring has adapted to blend into the sands and seabed surfaces. This natural camouflage helps them find food and avoid attack.

Many animals have disruptive coloration. Instead of overall colour, distinctive designs do the trick. Spots, stripes or even patches camouflage the animal. The wavy lines of a zebra blend in with the wavy lines of the tall grass around it. In this case, the pattern is more important than the colour. If a zebra is standing still in a field of tall grass, a lion may overlook it completely. This works for a lone zebra, but what about a herd? Zebras usually travel in large groups and stay very close to one another. In a big group, the pattern of each zebra’s stripes blends in with the stripes of the zebras around it. This is confusing to the lion. It sees a large, moving, striped mass instead of many individual zebras. The lion has trouble picking out any one zebra and can’t zoom in for an attack.

Many fish species are similarly camouflaged. Their vertical stripes may be brightly coloured, which makes them stand out to predators, but when they swim in large schools, their stripes all meld together. This confusing spectacle gives predators the impression of one big, swimming blob. The most famous colour changer, the chameleon, can make its skin appear yellow, green, brown, blue, red, even white or black. Surprisingly, chameleons do not do this to hide themselves. The colour switch is actually influenced by changes in the surrounding temperature, light and mood. Chameleons communicate using colour to convey their emotions. Colour adaptations are more effective survival tools than the sharpest teeth, claws and beaks could ever be.

 gandhim@nic.in

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