The white tiger is a rare pigmentation variant 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. White tigers are distinct for the normal coloration in that they lack the pheomelanin pigment that in normal tigers produces the orange color. They still produce the other color pigment, eumelanin, and hence are not considered albino.
Compared to normal colored tigers without the white gene, white tigers tend to be somewhat bigger, both at birth and as fully grown adults. Kailash Sankhala, the director of the New Delhi Zoo in the 1960s, said "one of the functions of the white gene may have been to keep a size gene in the population, in case it's ever needed." The white tiger is not considered a tiger subspecies, but rather a mutant variant of the existing tiger subspecies.
Dark-striped white individuals are well-documented in the Bengal Tiger subspecies, also known as the Royal Bengal or Indian tiger. (Panthera tigris tigris or P. t. bengalensis), and may also have occurred in captive Siberian Tigers (Panthera tigris altaica), as well as having been reported historically in several other subspecies. Currently, several hundred white tigers are in captivity worldwide, with about one hundred being found in India.
The unusual white coloration of white tigers has made them popular in zoos and entertainment showcasing exotic animals. German-American magicians Siegfried & Roy became famous for breeding and training two white tigers for their performances, referring to them as "royal white tigers," the white tiger's association with the Maharaja of Rewa.
Martand Singh, the last Maharaja of Rewa, captured the first living white tiger observed in nature, during his 1950 visit to Govindgarh jungle at Rewa, Madhya Pradesh, India. With help from official veterinary experts, he attempted breeding the white tiger with colored female tigers. Though initial attempts failed, he did eventually succeed and created a second generation of white tigers.