Tuesday, September 13, 2011

Bengal Tiger

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. Panther- a tigris is the national animal of India.Its coat is a yellow to light orange, and the stripes range from dark brown to black; the belly is white, and the tail is white with black rings. A mutation of the Bengal subspecies, the white tiger, has dark brown or reddish brown stripes on a white background, and some are entirely white. Black tigers have tawny, yellow or white stripes on a black background color. The skin of a black tiger, recovered from smugglers, measured 259 cm (102 in) and was displayed at the National Museum of Natural History, in New Delhi. The existence of black tigers without stripes has been reported but not substantiated.
The total body length, including the tail, of males is 270 to 310 cm (110 to 120 in), while females are 240 to 265 cm (94 to 104 in).The tail measures 85 to 110 cm (33 to 43 in), and the height at the shoulder is 90 to 110 cm (35 to 43 in).The average weight of males is 221.2 kg (488 lb), while that of females is 139.7 kg (308 lb).
Male Bengal tigers from the northern Indian subcontinent are as large as Siberian tigers with a greatest length of skulls of 332 to 376 mm (13.1 to 14.8 in). In northern India and Nepal, males have an average weight of 235 kg (520 lb), and females 140 kg (310 lb). Recent studies of body weights of the different tiger subspecies have shown that Bengal tigers are on average larger than Siberian tigers.
The Bengal tiger's roar can be heard for up to 3 km (1.9 mi) away.
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 these tigers 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.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.. 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.
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 woolly 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 on wards. 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.
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 andGray lan-gur. 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.
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 , 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.
Bengal tigers have also been known to take other predators, such as leopards, wolves, jackals, foxes, crocodiles, Asiatic black bearssloth bears, and d holes 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.
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 centers. Buyers choose the skins from dealers or tanneries and smuggle them through a complex interlinking network to markets outside India, mainly in China.
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.
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 traditionalmedicines 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.

No comments:

Post a Comment