White Bengal tigers are not albinos; they merely have a mutation on a recessive allele that codes for their orange fur to be white in color. These tigers still retain their black stripes and also have blue eyes.
Because the genetic code for a white tiger is recessive, a white tiger must carry copies of the gene on both chromosomes. A white tiger's parents are at least carriers for the recessive allele if not homozygous recessive of the gene. The reason why the gene for white tigers are rare is because it makes for poor camoflauge when hunting/hiding. Had the gene been present in Siberian tigers, it would have likely been selected for and white Siberian tigers would be common. White tigers grow at a faster and heavier rate than orange Bengal tigers.
White tigers are extremely rare and have only been spotted in India (the Bengal tiger subspecies). A naturally born white tiger is estimated to be born once in apporximately 10,000 births.
White tigers are not a distinct tiger sub-species. They are Bengal tigers.
Physical Differences between Regular and White Bengal Tigers:
White tigers have ice blue eyes and white fur with chocolate stripes.
They also differ from 'regular' tigers since they have pink noses and paw pads (opposed to black).
A Little History:
During the last 100 years, only about 12 white tigers have been spotted in the wild in India; giving an approximate ratio of 1 white tiger for every 10,000 normal pigmented (orange) tigers.
The white tiger origin was recorded in India during the start of the HB Mughal period from 1556 to 1605 A.D.
The first "modern" case of a white tiger being captured was in 1915. He was caught by the local maharajah who kept the tiger until its death.
The last spotting of a white Bengal tiger in the wild was in Rewa (Central India) on 27, May 1951. This male tiger was captured by the Maharaja Martand Singh of Rewa and named Mohan - it is from this animal that all white tigers in captivity today are descended.
In 1960, a two year old white tiger in Rewa, Mohini, was purchased by a businessman for US $10,000.00 and given to the National Zoo in Washington D.C. On 5th December 1960, Rewa appeared on the USA White House lawn with then president, Eisenhower.
Rewa was used to try and breed more white tigers in the USA (with normal orange tigers) but her offspring had various physical defects.