Tigers

Grasslands for the tiger

Print edition : October 27, 2017

At the Parambikulam tiger reserve, which supports diverse habitat types. Photo: ANANT ZANJALE

These super cats need tranquillity or, technically speaking, large inviolate expanses for resting, loafing, breeding and rearing their cubs. Photo: SANJAY KUMAR SHUKLA

Barasingha at Kanha. Special habitat improvement practices are needed for this species of deer. Photo: ANIRUDDHA DHAMORIKAR

The tiger is at the top of the ecological pyramid, with no predator of its own, but is threatened with a wide range of challenges. Photo: SANJAY KUMAR SHUKLA

The grasslands of Corbett also support mega-herbivores such as elephants. Photo: NIKHILESH TRIVEDI

The gaur, also known as the Indian bison, is a grazer and browser. Photo: ANANT ZANJALE

At the Namdapha tiger reserve, which is home to special Himalayan, Indo-Burmese and Indo-Chinese floral attributes. Photo: ANANT ZANJALE

Tigers need a good prey base for their survival. Photo: SANJAY KUMAR SHUKLA

The sambar is an important prey species for the tiger. Photo: SUDHIR MISHRA

The hog deer was once a chief prey of the tiger at Corbett. Its population has drastically shrunk owing to habitat loss. Photo: NIKHILESH TRIVEDI

A deer herd crossing in Corbett, which is home to vast grasslands and well-distributed water. Photo: NIKHILESH TRIVEDI

An alpine meadow of Uttarkashi in Uttaranchal. It is also regarded as a semi-natural grassland. Photo: G.S. RAWAT

The hard ground barasingha. Photo: SUDHIR MISHRA

In an extremely anthropogenic landscape, it has become important to launch a habitat and prey-base restoration programme for recovery of tiger numbers in India across a wide range of wildlife ecosystems.

WE were atop an elephant ambling through a patch of stately sal forest at Kanha. It was late afternoon and the setting sun’s mild rays shone through the tall dark trees, gradually lengthening their silhouettes. The persistent shrill alarm calls of axis deer and the guttural calls of langur had now grown louder and seemed close by. We turned the elephant towards the grassland, one of the prime meadows of the protected area, and emerged into an astoundingly huge assemblage of axis deer and hard ground barasingha.

The tension was palpable, with animals grazing fitfully. While I was looking for the predator, I also wondered at this extremely precious patch of landscape that had sustained hundreds of thousands of ungulates for a very long time. Not only did this seemingly ordinary grassy glade support the herbivory of a wide range of ungulate species, it indirectly supported carnivores, especially tigers, whose survival depends solely on herbivores.

By this time I had missed a most thrilling action of the natural world. The slight commotion made us turn the elephant back, and I saw that a tigress had caught a male chital by the throat, knocked it down, and overpowered it. The brief hush that had fallen over the entire scenario again blended into life-continuum, and it was business again as usual.

Tiger habitat

Regarded as the “spirit of the Indian jungle”, the tiger occupies the top of the ecological pyramid with no predators of its own. Some of the finest tiger-bearing protected areas of India are examples of good, if not ideal, tiger habitats. Tigers are obligate carnivores, solely animal-meat eaters, and their habitats encompass, for all practical purposes, those of their prey base itself in forests. These super cats also need tranquillity or, technically speaking, large inviolate expanses for resting, loafing, breeding and rearing their cubs. While much of their diet is composed of different ungulate species, they also prey upon ground-dwelling mammals and other opportune prey species. They are also known to sometimes prey upon cattle inside or outside forests. Highly adaptable, tigers have survived a wide temperature range, varied climates and topographies and diverse forest and habitat types. Naturally, they occur across a wide range of biogeographical regions and diverse ecosystems in the country, and the composition of their prey base is bound to vary across these regions.

The occurrence of a wide range of wildlife species, forming the prey base, depends exclusively upon the suitability of habitats to wildlife, with food, water and cover. Depending upon its food habits, an animal species, however, may require more than one habitat type for its existence. It is, therefore, desirable that there is good intermixing of different habitat unit types and that they are well distributed. Tigers’ prey base requires excellent rangelands and forest habitats for healthy propagation. In wildlife management parlance, rangelands include large and small grasslands, savannahs, openings and blanks, and scrub and stunted vegetation, and are regarded as an extremely important habitat type supporting a huge number of animals belonging to a wide range of ungulate species across the country.

Generally speaking, barring a few specialised species, ungulates’ herbivory includes both grazing and browsing. Animals lower their heads to feed or graze on grass and grass-like small plants or raise their heads to feed or browse on all edible parts of shrubs and small trees. In this way, from the standpoint of dietary requirements, taller trees, especially those without edible fruits, carry no special value for wild ungulates in a protected area.

The tiger’s diet is mainly composed of different species of ungulates, which are hoofed animals that roam the wilds of our country and are of two types: even-toed and odd-toed. There are a total of around 35 species of even-toed ungulates; these include deer, antelope, camel, sheep, goat and pig. The odd-toed ungulates include 18 species of rhinos, equids (such as wild ass) and tapirs, sometimes reported close to the India-Myanmar border. Not all ungulate species are wild, though. Wild ungulates are herbivorous and, with the exception of wild pigs to some extent, feed on the vegetative parts of plants, including grass, leaf, bark, fruit, pods, rhizome and root.

The ungulate species are distributed across different terrain and landscape features of 10 biogeographic regions of India that include protected areas and managed forests. Each ungulate species has its own ecological requirements; some of them also face serious threats. While highly specialised species inhabit special habitat types, several species coexist in a wildlife ecosystem, in a natural segregation on the basis of ecological niche partitioning, or routine separations on the basis of food habits, habitat types and specific ecological needs.

Nature has helped the ungulate species evolve different feeding strategies and mobility to reduce competition among themselves. They have different preferences and they also adopt different foraging tactics to exploit available resources.

Habitat loss

The tiger prey base is a critical determinant of tiger densities across tiger landscapes, small or large. Habitat loss is understood to be the key driver of decline in tiger population in the country. Experts suggest that we have already lost around 94 per cent of tiger habitat in the last century. Habitat loss and habitat degradation are directly and indirectly attributable to anthropogenic pressures and activities. While no wildlife habitat on the planet has remained uninfluenced by anthropogenic disturbances for millennia, nothing seemed amiss owing to low population pressure and a congenial environment in most parts of the country. Adverse changes were, of course, taking place slowly and silently. Besides, natural resources were simply regarded as god-given, and it was also too early to think about the systematic conservation of natural resources. Hence, losses and degradation as a result of the needs of a rapidly increasing human population were not in focus until, say, around 50 years ago.

The few natural grasslands in our country are in different stages of degradation and affected by weed or shrub infestation. With the exception of the Bugyal, or alpine grasslands, of Uttarakhand, the Banni of Gujarat and the Shola of south India, which are considered semi-natural, all our grasslands are man-made. Natural grasslands, such as the steppes of eastern Europe and central Asia, the pampas of South America, the prairies of North America, and the savannahs of Africa, occur as “climatic climax”, with grass species as their climax or ultimate vegetation.

Most grasslands in India are “plagioclimax”, with a human-induced stage of arrested ecological succession. These grasslands have remained arrested due to anthropogenic activities such as tree and shrub cutting, burning, grazing, and farming. Besides, natural grassland ecosystems elsewhere are governed by climatic conditions, including low rainfall, drought and thin soils, that are markedly different from those that control man-made grasslands in the country.

Most of our protected areas are relatively small, although some of them might be completely inviolate. Some large protected areas may also have human settlements, agricultural practices and cattle. Protected areas have interface problems with the surrounding agricultural land, and also those within, and developmental activities. Agricultural landscapes are the main source of invasive species, and conventional practices strengthen these source pools, increase immigration and the colonisation success rates of invasive plant species. The chronicity of this phenomenon disturbs habitats and makes plant communities species-poor, rendering them vulnerable to invasion as they cannot offer biotic resistance. Agricultural pests are also known to impact small-sized protected areas.

The use of indiscriminate cool burns throughout the cold season just to reduce serious fire hazards in the summer has done more harm than good. The practice gradually alters grasslands for coarse, unpalatable and fire-hardy species. Overgrazed and degraded grasslands are the worst affected by this practice. Grasslands with winter rain and low preceding rainfall also respond unfavourably to cool burns.

Substantial parts of landscapes in the country are under immense biotic pressure and have been rendered scrappy, with hopelessly fragmented forests, low cover value for wildlife and degraded and weed-infested plains. These are typically occupied by huge human and cattle populations and are witness to a vast range of land uses that are not supportive of forests and vegetal cover.

Now there is a growing realisation that adverse changes in grasslands the world over are also connected to climate change. Although this phenomenon is not well understood yet, it is known that erratic temperature and precipitation may have a significant effect on the composition, distribution and abundance of plant species. Experts say that highly invasive weed species may be particularly favoured by the disturbing influences of global climate change.

Habitat loss and the chronicity of poor habitat result in a wide range of complications as far as ungulate populations in a protected area are concerned. The most serious problem is a gradual loss of immunity against infections and diseases, making them vulnerable to different parasitic loads. Besides losing weight, they may also contract tuberculosis due to chronic undernutrition. Weakness exposes ungulate populations to local epidemic diseases transmitted from cattle, and may also result in high mortality. Population growth in different species is affected and this can have serious implications for tiger populations.

Recovery programme

India’s firm commitment to tiger conservation was again reflected when it signed the St. Petersburg resolution to double the world tiger population by 2022. While there is no harm in setting such a statistical goal, we have to be cautious to ensure that it does not devolve into a “numbers game”, drawing potential tiger states into unnecessary competition. As conservation gets tougher by the day on an extremely anthropogenic landscape, no ideal situation is in sight as far as habitat recovery is concerned. We have to move consistently and systematically with all the scientific and intellectual resources at our command.

Against this backdrop, it has become important to launch an all-out habitat and prey-base restoration programme for tiger recovery, especially in protected areas. As different habitat types lie across a wide range of wildlife ecosystems, each having its own set of problems, it is not possible to give a general prescription for the entire country. We can, however, make a basic code of guidelines for habitat recovery for further discussion and consequent additions and alterations.

While this may sound impractical, we need to expand the core areas or critical tiger habitats of tiger reserves. Besides some of the first nine tiger reserves, a few relatively new tiger reserves with huge potential should have a core zone of at least 2,000 square kilometres. These time-tested representative protected areas in different landscapes will help augment tiger populations in future.

We can also think of constituting several long-term region-wise specialist groups of retired forest officers and range ecologists to draw up protected area-specific habitat improvement programmes. This is extremely important and will also put an end to the personalised trial and error approach. These groups need to closely watch the implementation of these programmes at every stage and monitor the results of such initiatives.

We also need to maintain detailed year-wise documentation of site-specific habitat improvement inputs, such as periodic observations, monitoring, and inspection remarks.

Basic habitat recovery initiatives may include annual and perennial weed eradication, brushwood eradication, restocking of degraded grasslands, fencing off of sites for relief from overgrazing, and propagation of aquatic plants in waterbodies for specialised animals. The list of such activities may vary across wildlife ecosystems.

All relocated village areas should also be integrated into the surrounding wildlife habitat by undertaking special grassland improvement programmes. Applications of several habitat-improvement techniques will greatly restore these anthropogenic sites and sustain ungulate populations in the coming years.

Some protected areas have already mastered the art and science of tiger capture, translocation and release. If required, tigers should also be shifted to select areas to build new populations. The same is also valid for ungulate species. They can also be translocated from high- to low-density areas. Recently, the Kanha management shifted around 1,000 axis deer within the protected area itself without mortality.

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