For the identification of insects and other fauna and flora of South Africa.

Wednesday, July 15, 2009

White Bengal Tiger

Sreddy Yen is a young student from my home town, Pretoria. You might be interested to find out what he did during his school vacation. Please check out his blog by clicking here. We can all learn something from students like him. Thank you Sreddy!!

I found this information so interesting, I copied all of it from Wikipedia. Thanks to them for this wonderful article. This picture was taken of the one in our local zoo.

A white tiger is a tiger with a recessive gene that creates the pale coloration. Another genetic characteristic makes the stripes of the tiger very pale; white tigers of this type are called snow-white or "pure white". This occurs when a tiger inherits two copies of the recessive gene for the paler coloration, which is rare. White tigers have a pink nose, pink paw pads, grey-mottled skin, ice-blue eyes, and white to cream-colored fur with black, ash grey, or chocolate-colored stripes. Mr. H.E. Scott of the Indian police gave this description of a captive white tiger's eyes: "The colorings of the eyes are very distinct. There is no well defined division between the yellow of the comex and the blue of the iris. The eyes in some lights are practically colorless merely showing the black pupil on a light yellow background."

White tigers are not albinos and do not constitute a separate subspecies of their own and can breed with orange ones, although all of the resulting offspring will be heterozygous for the recessive white gene, and their fur will be orange. The only exception would be if the orange parent was itself already a heterozygous tiger, which would give each cub a 50% chance of being either double-recessive white or heterozygous orange. If two heterozygous tigers, or heterozygotes, breed on average 25% of their offspring will be white, 50% will be heterozygous orange (white gene carriers) and 25% will be homozygous orange, with no white genes. In the 1970s a pair of heterozygous orange tigers named Sashi and Ravi produced 13 cubs in Alipore Zoo, of which 3 were white. If two white tigers breed, 100% of their cubs will be homozygous white tigers. A tiger which is homozygous for the white gene may also be heterozygous or homozygous for many different genes. The question of whether a tiger is heterozygous (a heterozygote) or homozygous (a homozygote) depends on the context of which gene is being discussed. Inbreeding promotes homozygosity and has been used as a strategy to produce white tigers.
White tigers in the wild
An article appeared in the Miscellaneous Notes of the Journal Of The Bombay Natural History Society on Nov. 15, 1909 which reported that a white tigress was shot in the Mulin Sub-Division Forest of the Dhenkanal State in Orissa. The report originally appeared in the Indian Forester in May 1909, and was made by Mr. Bavis Singh, Forest Officer. The ground color of the white tigress was described as pure white and the stripes as deep reddish black. It was shot over a buffalo kill and "was in good condition not showing any signs of disease." Col. F.T. Pollock wrote in Wild Sports of Burma and Assam, "Occasionally white tigers are met with. I saw a magnificent skin of one at Edwin Wards in Wimpole Street, and Mr. Shadwall, Assistant Commissioner in Cossyah and Jynteah hills, also has two skins quite white." Mr. Lydekker wrote in Game Animals of India (1907) about five more white tiger skins: "A white tiger was exhibited alive at Exeter Change about 1820; a second was killed in Poona about 1892; in March 1899 a white tiger was shot in Upper Assam and the skin sent to Calcutta, where a fourth specimen was received about the same time. The Maharaja of Kuch-Behar also possesses a white tiger-skin." (The white tiger exhibited at Exeter Change in London in 1820 was the first white tiger in Europe.)

S.H. Prater wrote in The book of Indian Animals (1948) that "White or partially white tigers are not uncommon in some of the dry open jungles of central India." It is a myth that white tigers did not thrive in the wild. India planned to reintroduce captive-bred white tigers to the wild to a special reserve near Rewa. In the wild white tigers reproduced and bred white for generations. A.A. Dunbar wrote in Wild Animals Of Central India (1923) that "White tigers occasionally occur. There is a regular breed of these animals in the neighborhood of Amarkantak at the junction of the Rewa state and the Mandla and Bilaspur districts. When I was last in Mandla in 1919, a white tigress and two three parts grown white cubs existed. In 1915 a male was trapped by the Rewa state and confined. An excellent description of the animal, by Mr. Scott of the Indian police, has been published in Vol. XXVII No. 47 of the Bombay Natural History Society's journal." The previously mentioned article from The Journal Of The Bombay Natural History Society "Miscellaneous Notes: No. 1-A WHITE TIGER IN CAPTIVITY (with a photo)" states "The white tiger in captivity in Rewa was caught in December 1915 in the jungles of the State near Sohagpur. He was about two years of age at the time. There were two more white tigers in Southern Rewa related to this tiger but it was believed that the mother of this animal was not white." "These white tigers roam in the neighboring British Districts of the Central Provinces and seem to be living in the Maikal ranges of mountains." There is ample evidence that white tigers survived as adults in the wild. Victor H. Cahalane reported white tigers in northern China in 1943: "...north China has produced a number of albinos, with the inevitable faint brown stripe. Very rare melanistic (black) tigers are known." White tigers are not albinos. These would have been white individuals of the Amur tiger subspecies (Panthera tigris altaica), also known as the Siberian tiger. White tigers were reported from northern China and Korea. White tigers have cultural significance in both countries. White tigers were also part of the folklore on Sumatra and Java.

Jim Corbett filmed a white tigress in the wild which had two orange cubs. This film footage was used in the 1984 National Geographic movie Man Eaters Of India, which is based on Jim Corbett's 1957 book by the same title. This is further proof that white tigers survived and reproduced in the wild. The website of the Bandhavgarh National Park, in the former princely state of Rewa, in Madhya Pradesh, features pictures of white tigers, and states "The forests of Bandhavgarh are the white tiger jungles of yesteryears." Today there are 46 to 52 orange tigers living in Bandhavgarh, the largest population of tigers in any national park in India. The tiger is an endangered species.