Plants and an­i­mals

It is a won­der­ful world of mu­tual co­op­er­a­tion and co­ex­is­tence.

Alive - - Contents - By Maneka San­jay Gandhi

Plants and an­i­mals are so in­ter­de­pen­dent that many plants change them­selves, and even where they grow, in or­der to ac­com­mo­date in­sects. For in­stance, the Bee Orchid of the Mediter­ranean has adapted its colour, shape and tex­ture to make it­self look like a fe­male bee. It also re­leases scents (pheromones) to at­tract male bees. In their haste to get in­side the plant the males cover them­selves with pollen which they trans­fer to the next bee orchid.

The ham­mer orchid of Aus­tralia looks and smells like a fe­male wasp, to lure males to both de­posit and pick up pollen. The Fly Orchid se­cretes sex pheromones that at­tract male dig­ger wasps who at­tempt to mate with the flow­ers. Once spent, the wasps fly off cov­ered in the flow­ers’ pollen, help­ing it to re­pro­duce.

The pas­sion flower vine doesn’t want but­ter­flies lay­ing eggs on its leaves as, once they hatch into cater­pil­lars, they eat the vine. So it has de­vel­oped lit­tle yel­low spots on its leaves that look like Heli­co­nious but­ter­fly eggs. This con­vinces fe­male but­ter­flies to look else­where so that their off­spring don’t have to com­pete with other cater­pil­lars when they hatch.

The Venus fly­trap pro­duces smells that mimic food, lur­ing in flies which it then eats. Sci­en­tists have just found a new and bizarre form of mimicry: a plant, Cer­a­to­caryum ar­gen­teum of South Africa, which im­i­tates in shape, size and smell an­i­mal fae­ces of a lo­cal small an­te­lope called Bon­te­bok. What does the plant gain from this mimicry? It fools dung bee­tles, who mis­take the seeds for an­te­lope dung and roll the dung balls away and bury them.

By fool­ing the bee­tles, the plant gets them to dis­perse the seeds but hide them from seed preda­tors and de­struc­tive fires, giv­ing them a head start in ger­mi­na­tion. The habi­tat of C. ar­gen­teum is swept reg­u­larly by fire, and, un­like many plants, this species doesn’t re­sprout af­ter be­ing burnt. So the abil­ity to get its seeds away from the flames is ob­vi­ously thought out.

If plants try and look like an­i­mals to sur­vive, many an­i­mals try and look like plants so that they can sur­vive and

NEW AND BIZARRE Sci­en­tists have just found a new and bizarre form of mimicry: a plant, Cer­a­to­caryum ar­gen­teum of South Africa, which im­i­tates in shape, size and smell an­i­mal fae­ces of a lo­cal small an­te­lope called Bon­te­bok. What does the plant gain from this mimicry?

Match­ing in­sects

Leaf in­sects are so adept that they even mimic leaves that have been par­tially eaten by cater­pil­lars. The stick in­sect has a brown twig like ap­pear­ance and sways back and forth to seem like branches sway­ing in the breeze.

The wings of the Kal­lima but­ter­fly of Su­ma­tra match the colour, shape and struc­ture of dead leaves. Many spec­i­mens even have mark­ings mim­ick­ing patches of mould.

Chloro­phyll is the green pig­ment in plant cells. The sea slug Elysia chlorot­ica, that lives in sea­weed, takes chloro­phyll from al­gae and turns it­self green, look­ing like a leaf that crawls.

South Amer­ica’s fresh­wa­ter leaf fish hangs limply in the wa­ter look­ing like an­other dead leaf float­ing by. When a fish drifts by, the float­ing “leaf” sud­denly lunges out and seizes its prey in a deadly grasp. In ad­di­tion to their bursts of speed, leaf fish pos­sess very large jaws that al­low them to take on prey larger than them­selves.

To catch birds, the African vine snake wraps its tail around a tree branch and holds its body out rigidly to look like a twig. It then sticks out its orange tongue, which re­sem­bles an in­sect, to at­tract birds.

The Pep­pered Moth cater­pil­lar of Great Bri­tain im­i­tates flat twigs, vary­ing cap­ture prey. In­stead of spin­ning a web, the crab spi­der, with a pink body and legs, sits on the petals of a pink flower.

But­ter­flies, hover flies, and bees come to feed on the flower and fall prey to the wait­ing crab spi­der. Some crab spi­ders change their colour from yel­low to white depend­ing on the kind of flow­ers in the gar­den.

Flower man­tises use the same method. The Orchid Man­tis is white and soft pink with flat, heart-shaped lobes on its legs that look like flower petals. Man­tises can change colour in a few days to match their en­vi­ron­ment.

They stay in white or pink flow­ers to avoid be­ing eaten by birds and to catch pol­li­nat­ing in­sects who set­tle on them think­ing they are flow­ers. Some man­tises are green to match green petals.

Chang­ing with sur­round­ing

thin leaves. This al­lows them to sur­vive their bird preda­tors.

Stick in­sects, or phas­mids, which are also the world’s longest in­sects, re­sem­ble sticks and leaves. Some have cylin­dri­cal, stick-like bod­ies, while oth­ers have flat­tened leaflike shapes. The body is of­ten fur­ther mod­i­fied to re­sem­ble veg­e­ta­tion, with ridges re­sem­bling leaf veins, bark-like nod­ules. A few species are even able to change their pig­men­ta­tion to match their sur­round­ings.

The bod­ies of some species (such as Pseu­do­di­a­can­tha mack­lotti and Bac­trodo­dema cen­tau­rum) are cov­ered in mossy out­growths. Re­main­ing ab­so­lutely sta­tion­ary for a long time en­hances their dis­guise, as does sway­ing from side to side like leaves or twigs.

Bark Pray­ing Man­tises of the Ama­zon are cam­ou­flaged with flat­tened, mot­tled bod­ies that look like lichen, moss, dead leaves or bark. And when dan­ger threat­ens, since they fly poorly, they leap to the for­est floor, flut­ter­ing to the ground like so many dead leaves.

Plants that re­sem­ble an­i­mals, an­i­mals that re­sem­ble plants. What a won­der­ful world! To join the an­i­mal wel­fare move­ment con­tact gand­him@nic.in, www.peo­ple­foran­i­malsin­dia.org in colour be­tween green and brown. The adult moth de­vel­ops a colour­ing that looks like the lichen on trees, which is where it hides dur­ing the day.

In the 1950s, coal smoke dark­ened Eng­land’s trees, so that light pep­per moths, which once blended nicely against bark, now stood out against the smudgy back­ground. So they changed their colour­ing to look like the dark­ened bark.

In the late 1900s, Bri­tain cleaned up its air and tree barks went from dark to light. Strangely, the moths went back to be­ing light coloured again.

Walk­ing stick in­sects of Cal­i­for­nia, Timema cristi­nae, have two colour pat­terns - some are solid green, oth­ers have white stripes run­ning up their bod­ies. Walk­ing sticks don’t have wings, so they live mostly on a sin­gle bush their whole life.

A new gen­er­a­tion of walk­ing sticks will dis­perse to a dif­fer­ent bush. One species of bush, that the in­sects live on, has thick green leaves. A solid green walk­ing stick blends right in with that fo­liage.

An­other species of bush grows nee­dle-like leaves. The white stripes on some walk­ing sticks di­vides into green strips, mak­ing them look like

Kal­lima but­ter­fly

Pas­sion

flower

Venus fly­trap

Orchid Man­tis

Walk­ing stick in­sect of Cal­i­for­nia.

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