Bengal tiger

Bengal Tiger Bengali: বাঘ Hindi: बाघ
Bengal Tiger in Bannerghatta National Park
Conservation status
Endangered  (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Felidae
Subfamily:	Pantherinae
Genus:	Panthera
Species:	P. tigris
Subspecies:	P. t. tigris
Trinomial name
Panthera tigris tigris (Linnaeus, 1760)

The Bengal tiger, or Royal Bengal tiger (Panthera tigris tigris), is a tiger subspecies native to India, Bangladesh, Nepal and Bhutan, and has been classified as endangered by IUCN as the population is estimated at fewer than 2,500 individuals with a decreasing trend. None of the Tiger Conservation Landscapes within the Bengal's tiger range are large enough to support an effective population size of 250.

The Bengal tiger is the most numerous of the tiger subspecies — with populations estimated at 1,706 in India, 200 in Bangladesh, 155 in Nepal and 67–81 in Bhutan.

The Bengal tiger is the national animal of Bangladesh and India.

Characteristics

A White Bengal Tiger at the Cougar Mountain Zoological Park.

Panthera tigris tigris

The Bengal tiger's coat is yellow to light orange, with stripes ranging from dark brown to black; the belly is white, and the tail is white with black rings.

Male Bengal tigers range in total body length including the tail from 270 to 310 cm (110 to 120 in), while females range from 240 to 265 cm (94 to 104 in). The head and body length of males from Nagarahole National Park ranged from 189 to 204 cm (74 to 80 in), with a tail length of 100 to 107 cm (39 to 42 in), while a female measured 161 cm (63 in), with a tail length of 87 cm (34 in). The weight of males captured in Chitwan National Park ranged from 200 to 261 kg (441 to 575 lb), and of females from 116 to 164 kg (256 to 362 lb). Males from the northern Indian subcontinent are as large as Siberian tigers with a greatest length of skull of 332 to 376 mm (13.1 to 14.8 in).

The white tiger is a recessive mutant of the Bengal tiger, which was reported in the wild from time to time in Assam, Bengal, Bihar and especially from the former State of Rewa. There is only one fully authenticated case of a true albino tiger, and none of black tigers, with the possible exception of one dead specimen examined in Chittagong in 1846.

Records

A heavy male weighing 258.6 kg (570 lb) was shot in Northern India in 1938. In 1980 and 1984, scientists captured and tagged two male tigers in Chitwan National Park that weighed more than 270 kg (600 lb). The largest known Bengal tiger was a male with a head and body length of 221 cm (87 in) measured between pegs, 150 cm (59 in) of chest girth, a shoulder height of 109 cm (43 in) and a tail of just 81 cm (32 in), perhaps bitten off by a rival male. This specimen could not be weighed, but it was calculated to weigh no less than 272 kg (600 lb). The heaviest known tiger was a huge male killed in 1967 that measured 322 cm (127 in) in total length between the pegs, 338 cm (133 in) over curves, and weighed 388.7 kg (857 lb). This specimen is on exhibition in the Mammals Hall of the Smithsonian Institution.

Two tigers shot in Kumaon and near Oude at the end of the 19th century allegedly measured more than 12 ft (370 cm).

Genetic ancestry

Bengal tigers are defined by three distinct mitochondrial nucleotide sites and 12 unique microsatellite alleles. The pattern of genetic variation in the Bengal tiger corresponds to the premise that they arrived in India approximately 12,000 years ago. This recent history of tigers in the Indian subcontinent is consistent with the lack of tiger fossils from India prior to the late Pleistocene and the absence of tigers from Sri Lanka, which was separated from the subcontinent by rising sea levels in the early Holocene.

Distribution and habitat

A Bengal tigress with her cubs at the Bandhavgarh National Park, India

In 2010, the wild population of Bengal tigers in the Indian subcontinent is estimated to be fewer than 2,500. Of these, 1,165–1,657 are found in India, 200–419 in Bangladesh, mostly in the Sunderbans, 100–194 in Nepal and 67–81 in Bhutan. Over the past century tiger numbers have fallen dramatically, with a decreasing population trend. None of the Tiger Conservation Landscapes within the Bengal tiger range is large enough to support an effective population size of 250 individuals. Habitat losses and the extremely large-scale incidences of poaching are serious threats to the species' survival. The extent of area occupied by tigers is estimated at less than 1,184,911 square kilometres (457,497 sq mi), a 41% decline from the area estimated in the mid-1990s.

In 1982, a sub-fossil right middle phalanx was found in a prehistoric midden near Kuruwita in Sri Lanka, which is dated to about 16,500 ybp and tentatively considered to be of a tiger. Tigers appear to have arrived in Sri Lanka during a pluvial period during which sea levels were depressed, evidently prior to the last glacial maximum about 20,000 years ago. Previously, there has been some speculation about the time of arrival of tigers in the Indian subcontinent, and that they reached southern India too late to colonize Ceylon, which earlier had been connected to India by a land bridge.

India

In the past, Indian censuses of wild tigers relied on the individual identification of footprints known as pug marks — a method that has been criticized as inaccurate. Using modern camera trap counting methods, the landmark 2008 national tiger census report estimates only 1,411 adult tigers in India, plus uncensused tigers in the Sundarbans delta mangrove forests.

In May 2008, forest officials at the Ranthambore National Park in Rajasthan spotted 14 tiger cubs. In June 2008, a tiger from Ranthambore was relocated to the Sariska Tiger Reserve, where all tigers had fallen victim to poachers and human encroachments since 2005.

As of June 2009, tigers are found in 37 tiger reserves spread across 17 Indian states.

Rivaling the Chitwan-Parsa-Valmiki Tiger Conservation Unit in Nepal for the title of the world's best tiger habitat is the Western Ghats forest complex in western South India, an area of 14,400 square miles (37,000 km²) stretching across several protected areas. The challenge here, as throughout most of Asia, is that people literally live on top of the wildlife. The Save the Tiger Fund Council estimates that 7,500 landless people live illegally inside the boundaries of the 386-square-mile (1,000 km²) Nagarhole National Park in southwestern India. A voluntary if controversial resettlement is underway with the aid of the Karnataka Tiger Conservation Project led by K. Ullas Karanth of the Wildlife Conservation Society.

A 2007 report by UNESCO, "Case Studies on Climate Change and World Heritage" has stated that an anthropogenic 45-cm rise in sea level, likely by the end of the 21st century, according to the Intergovernmental Panel on Climate Change, combined with other forms of anthropogenic stress on the Sundarbans, could lead to the destruction of 75% of the Sundarbans mangroves.

The Forest Rights Act passed by the Indian government in 2006 grants some of India's most impoverished communities the right to own and live in the forests, which likely brings them into conflict with wildlife and under-resourced, under-trained, ill-equipped forest department staff. In the past, evidence showed that humans and tigers cannot co-exist.

Bangladesh

In 2004, 200 tigers were estimated to live in the country, most of them in the Sundarbans, and a few in the eastern hilly part of the country.

Nepal

The tiger population in the Terai of Nepal is split into three isolated and vulnerable subpopulations — inhabiting Chitwan National Park and the adjacent Parsa Wildlife Reserve, Bardia National Park and Sukla Phanta Wildlife Reserve. The number of adult tigers has reached 155 after a serious decline. A survey conducted from December 2009 to March 2010 indicates that 125 adult tigers live in Chitwan National Park and its border areas covering 1,261 km² (487 sq mi).

Once a royal hunting reserve, Chitwan became a national park in 1973. New economic incentives give villagers a direct stake in this renowned tourist attraction, with more than a third of revenues from park entrance fees being returned to the 300,000 people living in 36 villages in the surrounding buffer zone. As a result, locals are now creating and managing tiger habitat and consider themselves guardians of their tigers.

Bhutan

Tigers occur from an altitude of 200 m (660 ft) in the subtropical Himalayan foothills in the south along the border with India to over 3,000 m (9,800 ft) in the temperate forests in the north, and are known from 17 of 18 districts. Their stronghold appears to be the central belt of the country ranging in altitude between 2,000 and 3,500 m (6,600 and 11,500 ft), between the Mo River in the west and the Kulong River in the east. In 2010, camera traps recorded a pair of tigers at altitudes of 3,000 to 4,100 m (9,800 to 13,500 ft). The male was recorded scent-marking, and the female can also be seen to be lactating, confirming that the pair are living within their own territory, and strongly suggesting they are breeding at that altitude.

Ecology and behaviour

A male and female tiger in India interact with each other.

Tigers do not live in prides as lions do. They do not live as family units because the male plays no part in raising his offspring. Tigers mark their territory by spraying urine on a branch or leaves or bark of a tree, which leaves a particular scent behind. Tigers also spray urine to attract the opposite sex. When an outside individual comes into contact with the scent, it learns that the territory is occupied by another tiger. Hence, every tiger lives independently in its own territory.

Male Bengal tigers fiercely defend their territory from other tigers, often engaging in serious fighting. Female tigers are less territorial: occasionally a female will share her territory with other females. If a male happens to enter a female's territory, he will probably mate with her, if she is not already pregnant or has a litter. If she is pregnant or has a litter, he has no choice but to find himself a new territory and another potential mate. Similarly, females entering a male's territory are known to mate with him. Both males and females become independent of their mother around 18 months old, whereupon the cubs have to establish their own territories and fend for themselves. A male's territory is larger than a female's territory.

Hunting and diet

Tigers are obligate carnivores. They prefer hunting large ungulates such as chital, sambar, gaur, and to a lesser extent also barasingha, water buffalo, nilgai, serow and takin. Among the medium-sized prey species they frequently kill wild boar, and occasionally hog deer, muntjac and Gray langur. Small prey species such as porcupines, hares and peafowl form a very small part in their diet. Due to the encroachment of humans onto their habitat, they also prey on domestic livestock.

Bengal tigers have also been known to take other predators, such as leopards, wolves, jackals, foxes, crocodiles, Asiatic black bears, sloth bears, and dholes as prey, although these predators are not typically a part of the tiger's diet. Adult elephants and rhinoceroses are too large to be successfully tackled by tigers, but such extraordinarily rare events have been recorded. The Indian hunter and naturalist Jim Corbett described an incident in which two tigers fought and killed a large bull elephant. If injured, old or weak, or their normal prey is becoming scarce, they may even attack humans and become man-eaters.

In most cases, tigers approach their victim from the side or behind from as close a distance as possible and grasp the prey's throat to kill it. Then they drag the carcass into cover, occasionally over several hundred meters, to consume it. The nature of the tiger's hunting method and prey availability results in a "feast or famine" feeding style: they often consume 18–40 kilograms (40–88 lb) of meat at one time.

Reproduction and lifecycle

File:A tiger in Pilibhit Tiger Reserve.jpg

Tiger with a cub at the Bandhavgarh National Park, in India.

Males reach maturity at 4–5 years of age, and females at 3–4 years. Mating can occur at any time, but is most prevalent between November and April. A tigress comes into heat at intervals of about 3–9 weeks, and is receptive for 3–6 days. After a gestation period of 104–106 days, 1–4 cubs are born in a shelter situated in tall grass, thick bush or in caves. Newborn cubs weigh 780–1600 g (2 lb) and they have a thick wooly fur that is shed after 3.5–5 months. Their eyes and ears are closed. Their milk teeth start to erupt at about 2–3 weeks after birth, and are slowly replaced by permanent dentition from 8.5–9.5 weeks of age onwards. They suckle for 3–6 months, and begin to eat small amounts of solid food at about 2 months of age. At this time, they follow their mother on her hunting expeditions and begin to take part in hunting at 5–6 months of age. At the age of 2–3 years, they slowly start to separate from the family group and become transient — looking out for an area, where they can establish their own territory. Young males move further away from their mother's territory than young females. Once the family group has split, the mother comes into heat again.

Threats

A Bengal tiger in the Kanyakumari Wildlife Sanctuary

The most significant immediate threat to the existence of wild tiger populations is the illegal trade in poached skins and body parts between India, Nepal and China. The governments of these countries have failed to implement adequate enforcement response, and wildlife crime remained a low priority in terms of political commitment and investment for years. There are well-organised gangs of professional poachers, who move from place to place and set up camp in vulnerable areas. Skins are rough-cured in the field and handed over to dealers, who send them for further treatment to Indian tanning centres. Buyers choose the skins from dealers or tanneries and smuggle them through a complex interlinking network to markets outside India, mainly in China.

The illicit demand for bones and body parts from wild tigers for use in Traditional Chinese medicine is another reason for the unrelenting poaching pressure on tigers on the Indian subcontinent. For at least a thousand years, tiger bones have been an ingredient in traditional medicines that are prescribed as a muscle strengthener and treatment for rheumatism and body pain.

Other factors contributing to their loss are urbanization and revenge killing. Farmers blame tigers for killing cattle and shoot them. Their skins and body parts may however become a part of the illegal trade.

The Wildlife Protection Society of India (WPSI) works with law enforcement agencies in India to apprehend tiger poachers and wildlife traders throughout India. WPSI investigates and verifies any seizure of tiger parts and unnatural tiger deaths that are brought to their notice. Between 1994 and 2009, WPSI has documented 893 cases of tigers killed in India, which is just a fraction of the actual poaching and trade in tiger parts during those years. In 2007, police in Allahabad raided a meeting of suspected poachers, traders and couriers. One of the arrested persons was the biggest buyer of tiger parts in India who used to sell them off to the Chinese traditional medicinal market, using women from a nomadic tribe as couriers.

In 2006, India's Sariska Tiger Reserve lost all of its 26 tigers, mostly to poaching. In 2009, none of the 24 tigers residing in the Panna Tiger Reserve were left due to excessive poaching.

Human-tiger conflict

The Indian subcontinent has served as a stage for intense human and tiger confrontations. The region affording habitat where tigers have achieved their highest densities is also one which has housed one of the most concentrated and rapidly expanding human populations. At the beginning of the 19th century tigers were so numerous it seemed to be a question as to whether man or tiger would survive. It became the official policy to encourage the killing of tigers as rapidly as possible, rewards being paid for their destruction in many localities. The United Provinces supported large numbers of tigers in the submontane Terai region, where man-eating had been uncommon. In the latter half of the 19th century, marauding tigers began to take a toll of human life. These animals were pushed into marginal habitat, where tigers had formerly not been known, or where they existed only in very low density, by an expanding population of more vigorous animals that occupied the prime habitat in the lowlands, where there was high prey density and good habitat for reproduction. The dispersers had no where else to go, since the prime habitat was bordered in the south by cultivation. They are thought to have followed back the herds of domestic livestock that wintered in the plains when they returned to the hills in the spring, and then being left without prey when the herds dispersed back to their respective villages. These tigers were the old, the young and the disabled. All suffered from some disability, mainly caused either by gunshot wounds or porcupine quills.

In the Sundarbans, 10 out 13 man-eaters recorded in the 1970s were males, and they accounted for 86% of the victims. These man-eaters have been grouped into the confirmed or dedicated ones who go hunting especially for human prey; and the opportunistic ones, who do not search for humans but will, if they encounter a man, attack, kill and devour him. In areas where opportunistic man-eaters were found, the killing of humans was correlated with their availability, most victims being claimed during the honey gathering season. Tigers in the Sunderbans presumably attacked humans who entered their territories in search of wood, honey or fish, thus causing them to defend their territories. The number of tiger attacks on humans may be higher outside suitable areas for tigers, where numerous humans are present but which contain little wild prey for tigers.

In Nepal, the incidence of man-eating tigers has been only sporadic. In Chitwan National Park no cases have been recorded prior to 1980. In the following few years, 13 persons have been killed and eaten in the park and its environs. In the majority of cases, man-eating appeared to have been related to an intra-specific competition among male tigers.

Conservation efforts

A Bengal Tiger in a natural reserve in Karnataka, India.

An area of special interest lies in the Terai Arc Landscape in the Himalayan foothills in northern India and southern Nepal, where 11 protected areas comprising dry forest foothills and tall-grass savannas harbor tigers in a 49,000 square kilometres (19,000 sq mi) landscape. The goals are to manage tigers as a single metapopulation, the dispersal of which between core refuges can help maintain genetic, demographic, and ecological integrity, and to ensure that species and habitat conservation becomes mainstreamed into the rural development agenda. Nepal has developed a community-based tourism model, with a strong emphasis on sharing benefits with locals and on the regeneration of degraded forests. The approach has been successful in reducing poaching, restoring habitats, and creating a local constituency for conservation.

In India

Main article: Project Tiger

A Bengal tiger roams around in Ranthambore National Park, Rajasthan, India.

The Project Tiger initiative launched in 1972 initially reversed the population decline, which has resumed in recent years; India's tiger population decreased from 3,642 in the 1990s to just over 1,400 from 2002 to 2008.

The Indian Wildlife Protection Act of 1972 enables government agencies to take strict measures so as to ensure the conservation of the Bengal tigers. The Wildlife Institute of India estimates showed that tiger numbers had fallen in Madhya Pradesh by 61%, Maharashtra by 57%, and Rajasthan by 40%. The government's first tiger census, conducted under the Project Tiger initiative begun in 1973, counted 1,827 tigers in the country that year. Using that methodology, the government observed a steady population increase, reaching 3,700 tigers in 2002. However, the use of more reliable and independent censusing technology (including camera traps) for the 2007–2008 all-India census has shown that the numbers were in fact less than half than originally claimed by the Forest Department.

Following the revelation that only 1,411 Bengal tigers exist in the wild in India, down from 3,600 in 2003, the Indian government has decided to set up eight new tiger reserves. Because of dwindling tiger numbers, the Indian government has pledged US$153 million to further fund the Project Tiger initiative, set-up a Tiger Protection Force to combat poachers, and fund the relocation of up to 200,000 villagers to minimize human-tiger interaction.

Tiger scientists in India, such as Raghu Chundawat and Ullas Karanth, have faced criticism from the forest department. Both these scientists have been for years calling for use of technology in the conservation efforts. Chundawat, in the past, had been involved with radio telemetry (collaring the tigers). While studying tigers in Panna tiger reserve, he repeatedly warned the FD authorities about the problem of tiger poaching in the reserve; they remained in denial, producing bogus numbers of tigers in their reports, and banned Chundawat from the reserve. Eventually, however, it was proven he was right, as in 2008. the authorities admitted that all tigers in Panna have been poached. Karanth has been instrumental in using camera traps, radiotelemetry and prey counts. During the 1990s and early 2000s he also noticed that tiger numbers were significantly lower than the official figures; his insistence on using modern science in tiger conservation and uncompromising efforts to save tigers and their habitat have earned him many enemies.

The project to map all the forest reserves in India has not been completed yet, though the Ministry of Environment and Forests had sanctioned Rs. 13 million for the same in March 2004.

George Schaller wrote:

"India has to decide whether it wants to keep the tiger or not. It has to decide if it is worthwhile to keep its National Symbol, its icon, representing wildlife. It has to decide if it wants to keep its natural heritage for future generations, a heritage more important than the cultural one, whether we speak of its temples, the Taj Mahal, or others, because once destroyed it cannot be replaced."

In January 2008, the Government of India launched a dedicated anti-poaching force composed of experts from Indian police, forest officials and various other environmental agencies. Indian officials successfully started a project to reintroduce the tigers into the Sariska reserve. The Ranthambore National Park is often cited as a major success by Indian officials against poaching.

In Bangladesh

The Sundarbans tiger project is a Bangladesh Forest Department initiative that started its field activities in February 2005. The idea for creating such a project was first developed during a field survey in 2001, conducted by Md. Osman Gani, Ishtiaq U. Ahmad, James L. D. Smith and K. Ullas Karanth. They realized that the Sundarbans mangrove forest at the mouth of the Ganges River contained probably one of the largest populations of wild tigers left in the world. As such, there was an urgent need to start measures that would ensure the protection of this precious area. The Save the Tiger Fund and the United States Fish and Wildlife Service generously donated funds to support the initial phase of research that aimed to collect data on tiger ecology using telemetry, and study the tiger’s environment by assessing its habitat and prey. But management of a wilderness area needs more than just information on the species to be protected. Personnel with skills and resources to implement conservation strategies, and the general support of the country are also required. So from the research base, the project is evolving rapidly to also encompass capacity building and conservation awareness activities. It has been able to do so through the forward thinking approach to management taken by the Forest Department, and the incredible support of the Bangladeshi people. The project is administered by the Forest Department. At the field level, there is a team of 8 persons, made up of Forest Department personnel and one wildlife consultant from the University of Minnesota who advises on research strategies and trains staff.

In Nepal

The government aims at doubling the country's tiger population by 2022, and in May 2010, decided to establish Banke National Park with a protected area of 550 square kilometres (210 sq mi), which bears good potential for tiger habitat.

Ex situ

Bengal tigers have been captive bred since 1880 and widely crossed with other tiger subspecies. Indian zoos have bred tigers for the first time being at the Alipore Zoo in Kolkata. The 1997 International Tiger Studbook lists the global captive population of Bengal tigers at 210 individuals that are all kept in Indian zoos, except for one female in North America. Completion of the Indian Bengal Tiger Studbook is a necessary prerequisite to establishing a captive management program for tigers in India.

Admixed genetic heritage

In the late 1990s, microsatellite analysis was used to identify hybrids of Indian and Siberian tigers through polymerase chain reaction amplification of hair samples. The study revealed that two tigers of the wild population of Dudhwa National Park had alleles contributed by both subspecies. Both tigers had an Indian tiger mitochondrial haplotype indicating that these animals had an Indian tiger mother.

In July 1976, Billy Arjan Singh acquired a hand-reared tigress from Twycross Zoo in the United Kingdom, and reintroduced her to the wild in Dudhwa National Park with the permission of India's then-Prime Minister Indira Gandhi. In the 1990s, some tigers from this area were observed to have the typical appearance of Siberian tigers: white complexion, pale fur, large head and wide stripes. It was later proved that the tigress was a hybrid Siberian-Bengal tigress. Dudhwa tigers constitute about 1% of India's total wild population, but the possibility exists of this admixed genetic heritage being passed on to other tiger populations and jeopardizing the Bengal tiger as a distinct subspecies.

"Re-wilding" project in South Africa

In 2000, the Bengal tiger re-wilding project Tiger Canyons was started by John Varty, who together with the zoologist Dave Salmoni trained captive-bred tiger cubs how to stalk, hunt, associate hunting with food and regain their predatory instincts. They claimed that once the tigers proved that they can sustain themselves in the wild, they would be released into a free-range sanctuary of South-Africa to fend for themselves.

The project has received controversy after accusations by their investors and conservationists of manipulating the behavior of the tigers for the purpose of a film production, Living with Tigers, with the tigers believed to be unable to hunt. Stuart Bray, who had originally invested a large sum of money in the project, claimed that he and his wife, Li Quan, watched the film crew "[chase] the prey up against the fence and into the path of the tigers just for the sake of dramatic footage."

The four tigers involved in this project have been confirmed to be crossbred Siberian–Bengal tigers, which should neither be used for breeding nor being released into the Karoo, which for them is unsuitable habitat. Tigers that are not genetically pure will not be able to participate in the tiger Species Survival Plan, as they are not used for breeding, and are not allowed to be released into the wild.

In the USA

In October 2011, 18 Bengal tigers were among the exotic animals shot by the local sheriff's department after the 2011 Ohio exotic animal release.

In culture

An early silver coin of Uttama Chola found in Sri Lanka showing the tiger emblem of the Cholas.

The Shiva Pashupati seal with tiger to right of the seated Shiva figure Pashupati

The Bengal tiger has been a national symbol of India since about the 25th century BCE when it was displayed on the Pashupati seal of the Indus Valley Civilisation. On the seal, the tiger, being the largest, represents the Yogi Shiva's people. The tiger was later the symbol of the Chola Empire from 300 CE to 1279 CE and is now designated as the official animal of India.

• The logo of Bangladesh Cricket Board features a Royal Bengal Tiger.
• Cincinnati's National Football League team is named the Cincinnati Bengals.
• The Detroit's MLB team Detroit Tigers are nicknamed the Bengals.
• Dominican Republic's most successful baseball team Licey Tigers are nicknamed the Bengals.
• The team from Kolkata in the Indian Cricket League is called the Royal Bengal Tigers.
• Louisiana State University's Tigers are nicknamed the Bayou Bengals.

References

http://www.telegraphindia.com/1110329/jsp/frontpage/story_13780289.jsp

External links

• Cat Specialist Group: Bengal Tigers
• IUCN Red List of Threatened Species: Panthera tigris ssp. tigris
• Save The Tiger Fund: Bengal Tiger
• Sundarbans Tiger Project
• Information Resources on Tigers, Panthera tigris: Natural History, Ecology, Conservation, Biology, and Captive Care AWIC Resource Series No. 34, April 2006
• Guardian News and Media Limited: The four faces of the Bengal tiger
• Tiger - A chance encounter