Friday, March 26, 2010

Know About Royal Bengal Tiger !!!

The Bengal tiger, or Royal Bengal tiger (Panthera tigris tigris, previously Panthera tigris bengalensis), is a subspecies of tiger, found in India, Bangladesh, Nepal and Bhutan. According to WWF, there are about 2,100 Royal Bengal tigers in the wild today, including 1,411 in India, 450 in Bangladesh, 150 in Nepal and 100 in Bhutan.

The Bengal tiger was previously regarded as the second largest subspecies after the Siberian tiger even though recent scientific studies have shown that Bengal Tigers are, on average, larger than the Siberian Tigers. The Bengal subspecies P. tigris tigris is the national animal of Bangladesh, while at the species level, the tiger Panthera tigris is the national animal of India.

Physical characteristics
The total length (including the tail) for males is 270-367 cm, while females are 240–265 cm; the tail measures 85–110 cm long and the height at the shoulder is 90–110 cm. The average weight is 221.2 kg (487.7 lb) for males and 139.7 kg (308 lb) for females; however, those who inhabit the north of India and Nepal have an average weight of 235 kg (518 lb) for males and 140 kg (308.6 lb) for females. 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 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.

Tiger Records
Officially, the heaviest Bengal tiger with confirmed weight was a male of 258.6 kg (570 lbs) and was shot in Northern India in 1938; however, the heaviest captive males are two tigers (M105 and M026) weighing more than 270 kg (600 lb), tagged in Nepal in 1984. The largest known Bengal tiger, measured between pegs, was a male with a head and body length of 221 cm, 150 cm of chest girth, a shoulder height of 109 cm and a tail of just 81 cm, perhaps bitten off by a rival male. This specimen could not be weighed, but it was calculated to weigh no less than 272 kg. Finally, according to the Guinness Book of Records, the heaviest tiger known was a huge male hunted in 1967, measuring 322 cm in total length between pegs (338 cm over curves) and weighing 388.7 kg (857 lb). This specimen was hunted in northern India by David Hasinger and is actually on exhibition in the Smithsonian Institution, in the Mammals Hall.

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 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. However, a recent study of two independent fossil finds from Sri Lanka, one dated to approximately 16,500 years ago, tentatively classifies them as being a tiger.

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. 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.

Reproduction and lifecycle
Mating can occur at any time, but is most prevalent between November and April. Females can have cubs at the age of 3–4 years; males reach maturity by about 4 years old. After the gestation period of 103 days, 2-5 cubs are born. Newborn cubs weigh about 1 kg (2 lb) and are blind and helpless. The mother feeds them milk for 6–8 weeks and then the cubs are introduced to meat. The cubs depend on the mother for the first 18 months and then they start hunting on their own.

Hunting and diet
Bengal tigers are classified as obligate carnivores, meaning that they have a diet of strictly meat. Bengal tigers eat a variety of animals found in their natural habitat, including deer (sambar, chital, barasingha, hog deer and muntjac), wild boars, water buffalo, gaur, nilgai antelope, and occasionally other ungulates (such as Nilgiri tahr, serow and takin, where available); tigers have also been observed eating small prey, such as monkeys, hares, birds (primarily peafowl), and porcupines, but large and medium-sized ungulates provide the majority of biomass consumed by tigers, and are essential for their survival. 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 sick large bull elephant. Due to the encroachment of humans onto the Bengal tiger's habitat, Bengal tigers also eat domestic cattle. If injured, old, or weak, tigers may even consume humans. When a tiger consumes human flesh, it becomes known as a man-eater and may continue to prey on humans. The nature of the tiger's hunting method and prey availability results in a "feast or famine" feeding style. Tigers gorge themselves, often consuming 18–20 kg (40–60 lb) of meat at one time, as they may not be successful hunting again for several days. Bengal tigers prey on vulnerability, so they attack the last animal at the end of a herd, kill it, and then drag the animal's carcass to a safe location to consume it.

Population and distribution
A Bengal tigress with her cubs at the Bandhavgarh National Park, India The current population of wild Bengal tigers in the Indian subcontinent is estimated to be between 1,300 and 1,500. Of these, 1,411 are found in the wild in India while about 280 are found in Bangladesh, mostly in the Sunderbans. Over the past century tiger numbers have fallen dramatically. Of eight subspecies alive in 1900, three are now extinct and we have lost over 90 per cent of wild tigers. Poachers kill tigers not only for their pelts, but also for body parts used to make various traditional East Asian medicines. Other factors contributing to their loss are urbanization and revenge killing. Farmers blame tigers for killing cattle and shoot them. Poachers also kill tigers for their bones and teeth to make medicines that are alleged to impart the tiger's strength to the human who consumes the medicine. The hunting for Chinese medicine and fur is the biggest cause of the decline of the tigers.

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