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Conservation: Why Nilgai, Wild boar are vermin

Published : Aug 14, 2017, 2:15 am IST
Updated : Aug 14, 2017, 2:15 am IST

The proliferation of nilgai and wild boar is now endangering other wildlife.

Farmers have to fend for themselves and are at odds with the authorities as they have to protect their livelihood.
 Farmers have to fend for themselves and are at odds with the authorities as they have to protect their livelihood.

Everywhere one goes looking for wildlife in peninsular India, two animals jump up: the wild boar and the nilgai. The population of both has increased multifold, often at the cost of other species. Their main predator, the wolf, has all but disappeared from its known, traditional ranges, killed because wolves lift goats, sheep and children. The proliferation of nilgai and wild boar is now endangering other wildlife. Many argue that they form a large part of the diet of the feline predators. Wild boar and nilgai are known depredators of crops, but let us also understand how they alter forests when their numbers swell.

In all the scats that I have examined in Central India, I have seen a lot of animal remains. I have seen the hair of gaur most often, followed by sambar then by chital and finally a stray wild boar here and there, and just once I came upon the carcass of a bull nilgai killed by a tiger. In one instance I also found the claws of a leopard in a tiger’s scat. There is today a rebound in wildlife, earlier lost due to many factors. The loss of wildlife was attributed to poaching — harking back to the hunting tradition of India, which was subsequently stamped out. Today, though there is some poaching, with the coming of the cellphone with camera incidents are much fewer.   What major poaching happens is actually for the protection of crops. Electric fences, poisons, snares and traps are laid to dispatch crop-raiding wildlife.  Many non-target species fall foul of these indiscriminate, yet cruelly effective, methods.  (I am not referring to leopard, tiger, rhino and elephant poaching, which is motivated by commercial interests.)


Farmers have to fend for themselves and are at odds with the authorities as they have to protect their livelihood. Coming back to the issue of wild boar and nilgai, both degrade forests. Both are seen near human habitations more than in forests. Both inhabit open grassland with bush, the wild boar preferring thorny scrub with wallowing pools, while the nilgai prefers open wooded areas. Wild boars contaminate water sources with faecal matter that has a very high bacterial content.  They kill the fawns of deer and antelope; eat the eggs and chicks of ground-nesting birds. Over a period of time, the biodiversity is lost.

Apart from the loss of animal diversity, they also dig up roots, tubers and young saplings, especially of the gum tree Sterculia urens. Large sounders of wild boar are seen everywhere. They root under trees for worms and grubs, loosening the earth, and as a result, the trees are in danger of falling. Wild boar is not the preferred prey of feline carnivores. They constitute some three per cent of the total kills. At say, 3,000 odd tigers in India killing 52 animals each, per year, it amounts to some 1.56 wild boar of the total animals killed per tiger, or some 4,680 wild boar killed annually by all tigers combined; assuming that all the tigers are adults.

With, say, about 15,000 leopards and the same formula applied, they probably add 23,400 wild boars to their diet. Where wild boar abound, Prosopis juliflora (an invasive alien species) is usually seen in profusion. Are wild boars aiding its spread by consuming its pods and broadcasting its seeds? The manner in which the Prosopis is spreading, shows that there is some sort of a symbiotic relationship between the two. Nilgai are browsers and grazers given to the semi-arid and sub-humid regions that form their traditional range. They are not specialist feeders, so will eat almost anything green. They are very highly adaptive and can survive in almost all types of habitats. They have invaded the hill forests, primarily the stronghold of the sambar, and are pushing them out by out competing them for fodder and by simply out-breeding them. Sambars are browsers and not grazers, but will eat water plants. They constitute a major portion of the tiger’s diet.

Nilgai move to open areas where tigers will not be able to hunt them, so even with what looks like a good prey base, cattle kills occur. Tigers and leopards find that cattle, sheep and goats that are driven into the forests for grazing, are relatively easier to catch and kill. Nilgai are also known to destroy and decimate the biodiversity by eating young shoots and saplings.  They do not allow a forest to regenerate. They also dig up and eat the roots of some trees and the bark and the living tissues of trees, ringing and thus killing them. Over a period of time, this degrades the forest. Nilgai infested areas are usually forested with the Butea species, which indicates degraded forests.

Would the citizens of this country want to fritter away the natural heritage so vividly portrayed in our culture?

The people at large and the managers of wildlife and forests have to now decide whether we would want nilgai and wild boar over a myriad panorama of wildlife; a very biodiverse landscape with a healthy forest system having fewer conflicts, especially with the carnivores, or an area bereft of most wildlife except for wild boar and nilgai, with an ever diminishing population of the tiger and the leopard always at odds with the farmers and herders and a headache for the authorities.

Tags: wild boar, peninsular india, nilgai