|
| |
| Fauna : Tiger (Panthera Tigris) |
| |
 |
IUCN Status : Endangered CITES : Appendix I |
Wildlife (Protection) Act 1972 : Schedule I |
Lenght : Males 9 - 9.5 feet (275 - 290 cms)
Females 8 to 8.5 feet (260 cms)
|
Weight : Males : 400 - 500 lbs (180 - 230 Kgs)
Females about 100 lbs (45 Kgs) lighter than males
|
|
|
|
|
Abstract
Though still held as the ubiquitous embodiment of the Indian jungle, the Tiger has retreated perilously close to the brink of extinction driven there by the twin threats of habitat loss and unprecedented levels of poaching to satisfy the demand for Tiger products in China and the Far East.
The Tiger has a pelage that appears striking when seen in an enclosure yet provides perfect camouflage in the dappled light of the jungle. Endowed also with acute eyesight and olfactory powers, a sinuous structure with powerful forelimbs, the Tiger is a hunter par excellence and occupies the apex of the food pyramid.
Tigers are solitary animals. This does not preclude regular association with others of their kind. Tigers live within a fairly complex social web, the entirety of which has not been fully unravelled. Male Tigers reach sexual maturity between 4 and 5 years and females between 3 and 4 years. Gestation is 90-105 days and the litter generally consists of 2-4 cubs.
|
| |
 |
Although the paleontological evidence is fragmentary, Tigers are believed to have evolved in East Asia and from there colonized the rest of their range. It is an astonishingly wide distribution and stands testimony to the robust adaptability of this master predator.
Until quite recently 'tiger country' stretched from Bali and Java, 10° south of the Equator to more than 60° north in the Russian Far East and from the Eastern shores of Asia to the Caspian Sea. It encompassed a diverse array of habitats - from equatorial rainforest to temperate woodland, from semi-arid thorn scrub to mangrove swamp, from deciduous jungle to Caspian reed beds. In order to deal successfully with this diversity of climate, prey and vegetation types, Tigers evolved a number of variations based upon which scientists recognise 8 sub-species of the Tiger. (This conventional classification is presently under review).
There are however, limits to this adaptability. The genus Panthera - the Big Cats that can roar - evolved as hunters of deer. As the largest of the Big Cats, Tigers have specialised in the predation of the larger deer. Having originated in the well-wooded, well-watered lands of tropical and temperate Asia they are creatures of flood plain and forest. While they can push this envelope to some degree, their range is defined by the availability of adequate food, cover and water.
At the end of the 19th century the entire Tiger population, made up of all the supposed 8 sub-species, numbered an estimated 100,000 with 40,000 of them being found in India alone. Today the total population has fallen to under 7,000 with the Indian population estimated at between 3000 - 5000. The fact of course is that it is impossible to gauge the accuracy of any of these figures and no one really knows how many Tigers survive today. What is indisputable however, is that the Tiger has vanished from vast tracts of it's former range and that 3 of the 8 sub-species (See table) are extinct; one has been reduced to a non-viable population in the wild and the remaining 4 teeter on the edge of extinction.
Through much of its remaining range it is found in low densities brought about by fragmented and/or degraded habitat and depleted prey base. In such circumstances, this normally resilient species becomes vulnerable to poaching pressures fuelled by demand for Tiger parts and fur particularly from the increasingly prosperous East Asian region.
At present the highest densities of Tigers are encountered in the Indian sub-continent where the mosaic of woodland and grassland supports high prey biomass. Although essentially a hunter of the larger deer, wherever Tigers have encountered larger potential prey they have devised strategies to include them - or their young - in their normal diet. A classic example is the relatively high predation of adult Gaur by Tigers across southern and central India as also the inclusion of Wild Buffalo and young Rhinoceros in their regular diet in Nepal, Bhutan and Eastern India. This enlargement of the prey base has permitted higher Tiger population densities than would have been possible had Tigers not displayed this flexibility. The obverse is also true - wherever the regular prey has disappeared Tigers contrive to eke out an existence on whatever is available but at very low population densities.
|
|
 |
 |
Although the Tiger occupies the apex of the food pyramid and is the hunter par excellence it subscribes to a feast or famine regimen. Studies show that a Tiger kills once in seven or eight days. In the eternal evolutionary struggle between hunter and hunted it keeps a bare step ahead of its prey and has to work hard to make ends meet.Its requirements of meat are enormous. |
|
It has been estimated by various scientists and researchers working in India and Nepal that the requirement of meat by a male Tiger is in the region of 2200 to 2500 kgs a year.The requirements of a sub-adult or female Tiger would be about 300 kgs less. As only 70% of a kill is consumed, it is estimated that the average Tiger's requirement of living prey is in the region of 2800 to 3500 kgs per year. Females with cubs would need to consume substantially more.
The Tiger is essentially a solitary animal probably as a response to its closed environment that favours the lone hunter over the pride. Its striking pelage provides perfect camouflage in the dappled light of the jungle.
Prey are ambushed and the Tiger is superbly adapted to stalk and kill its prey. Aided also by the fact that its main prey species - the ungulates - see only in monochrome, plus other adaptations such as padded feet, digitigrade stance and a sinuous body, all of which permit noiseless stalking, the Tiger is able to get to within striking range without being detected. Their night vision is also extraordinary and with sensitive whiskers, and acute hearing, Tigers are also well adapted to hunting at night.
The forelimbs of the Tiger pack immense power and with its sharp, retractile claws, the Tiger manipulates its prey. Having gained a purchase on the quarry, the Tiger brings it down and then kills it by a quick neat bite at the throat or the nape of the neck. Large prey like Sambar and Gaur are usually killed by a throat bite, while with smaller prey, a nape bite is used. Death results from strangulation, or damage to the central nervous system, or even shock. Once the prey has been killed, the carcass is usually dragged into cover and away from the eyes of vultures and other scavengers and where the Tiger feels undisturbed. Tigers usually start feeding at the rump and generally remove the rumen and the intestines. If undisturbed, a Tiger stays with the kill for 3-4 days, feeding at any time of day or night, and could eat 40 to 80 kgs of meat over this period. |
|
|
 |
Tigers are solitary animals. This does not preclude regular association with others of their kind. Indeed, Tigers live within a fairly complex social web, the entirety of which has not been fully unraveled.Their social system is defined by highly developed territorial behavior practiced by adult, sexually mature individuals (3-4 years old) of both sexes. |
|
The territorial system is based upon the need for females to possess an area with adequate food water and shelter to support themselves and their cubs in lean times. For males the territorial imperative is to include as many females as possible to most effectively propagate their own genes.
The size of the territories varies considerably depending on the densiy of prey in the area, which is again a co-factor of vegetation type. According to Ullas Karanth's study "in Nagarahole in Southern India, where ungulates occur at high density of 50 to 75 animals/sq.km, the home ranges of breeding tigresses was found to be very small (10 -15 sq.km) and adult Tiger densities could exceed 15 Tigers/100 sq.km. At the other extreme, in Siberia where prey is scarce, female ranges may be in excess of 200 sq.km and Tiger densities correspondingly less."
Territories are maintained and protected mainly through advertisement, rather than tooth-and-claw confrontation. This advertisement takes the form of scent markings on trees, clumps of grass and bushes; scrape markings made upon the ground by the hind feet (on which the Tiger will sometimes defecate and deposit secretions from its anal glands or urinate). Scratch markings on trees serve both to clean the claws and as a visual territorial sign. Other forms of markings such as cheek rubbing and vegetation flattening also form part of the repertoire.
Transient Tigers are basically sub adult Tigers (both male and female) that have dispersed from their mother and are trying to find a territorial niche or home range for themselves. These individuals move back and forth through their mother's range and adjoining areas and as they grow bigger, are known to run into conflict with the residents. Serious fights have been recorded in which if the resident is killed or severely impaired, the transient Tiger would establish itself in the area. On the other hand many transients also get killed in such fights.
|
|
 |
|
Male Tigers reach sexual maturity between 4 and 5 years and females between 3 and 4 years. In most cases the evidence points to sexually mature Tigers also being territorial. Mating takes place when females come into estrous. This is preceded by increased scent marking and vocalization by the female. The courting male who responds to these signals might then stay with the female for anything between a few days and two-three weeks.
|
 |
|
They depend on mother's milk for the first eight weeks or so, after which the female takes them to her kills.Over the 22 months or so that they are with their mother, the cubs learn the ways of the jungle and hunting skills from their mother, all so essential once they have to fend for themselves. Although the female rears the cubs without any assistance from the male, the latter are not, in all cases, intolerant of their cubs. There have been cases (at Bandhavgarh Tiger Reserve in central India) of a male tolerating the presence of very young cubs even at a kill and also staying with them, without the mother's being present, when they were 18-19 months old.
According to Ullas Karanth "a tigress produces, on an average, a litter of 3 cubs every two and a half years. The average breeding tenure of females may be around 7-8 years and about half that for males. Only 50% of these cubs make it through the first year. Various factors such as disease, fires, floods, other predators (including man) and infanticide (killing of cubs fathered by the resident male, when his territory is taken over by a new male) account for this high mortality. Of the surviving juvenile Tigers, most make it to the dispersal age when competition starts amongst these transients for food, space, and mates." Generally male cubs leave the mother when they are about 18-22 months old and females somewhat later. Again, Ullas Karanth estimates that "about 20-30% of transient Tigers are estimated to die every year. Taking into account all the above factors, the average life expectancy at birth for the average Tiger is only about 3-5 years, although some resident Tigers can live to be 12 to 15 years old." |
| |
 |
References for the above article are:
Andrew C. Kitchener: Tiger distribution, phenotypic variation and conservation issues (Riding the Tiger)
Dr. Charles McDougal: Face of the Tiger, Andre Deutsch , 1977
K. Ullas Karanth :In Danger; Ranthambore Foundation 1997),
K. Ullas Karanth & Bradley M. Stith: Prey Depletion as a critical determinant of tiger population viability (Riding the Tiger)
Geoffrey and Diane Ward: Tiger Wallahs, Harper Collins, 1993
Further Reading
George B. Schaller : the Deer and the Tiger, University of Chicago Press, 1967
Valmik Thapar : Tiger - Portrait of a predator, Collins, 1986
Valmik Thapar : Tigers - The Secret life, Elm Tree Books, 1989
K.Ullas Karanth and James.D.Nichols: Estimation of Tiger densities in India using photographic captures and recaptures, Wildlife Conservation Society, 1994
K.Ullas Karanth : Tigers in India, a critical review of field censuses; Tigers of the World ( Tilson, R.L. and U.S.Seal eds.), Noyes Publications, Park Ridge, 1987
Mel Sunquist, K.Ullas Karanth and Fiona Sunquist :Ecology, behavior and resilience of the tiger and its conservation needs ; Riding the Tiger
K.Ullas Karanth, Mel Sunquist and K.M. Chinnappa : Long -term monitoring of tigers : lessons from Nagarahole ; Riding the Tiger
Joelle Wentzelll, Dale G Miquelle et.al.:Subspecies of tigers : molecular assessment using 'voucher specimens' of geographically traceable individuals ; Riding the Tiger
Raghu.S. Chundawat, Neel Gogate and A.J.T. Johnsingh -Tigers in Panna : preliminary results from an Indian tropical dry forest ; Riding the Tiger
James L.David Smith, Charles McDougal et.al :Metapopulation structure of tigers in Nepal ; Riding the Tiger
Eric D. Wikramanayake, Thomas Mathew, Ullas Karanth et.al :Where can tigers live in the future ? A framework for identifying high-priority areas for the conservation of tigers in the wild ; Riding the Tiger
Alan Rabinowitz :The status of the Indochinese tiger-Timetable of Extinctionseparating fact from fiction ; Riding the Tiger
( 'Riding the Tiger' - Tiger conservation in human dominated landscapes- Edited by John Seidensticker, Sarah Christie and Peter Jackson - 1999 .Published by Cambridge University Press, 1999. ) |
|
|
