The white tiger is the result of a genetic mutation that rarely occurs in the wild. A tiger with this gene mutation is often bred for whiteness in captivity, usually to attract visitors to a zoo or refuge. This type of breeding serves no conservation purpose. In addition to its bleached fur, white tigers have deep blue eyes, instead of the usual yellow.
The tiger is one of thirty-six cat species, and most closely related to the lion, leopard, and jaguar, all of which evolved from a common ancestor over 5 million years ago. The tiger is the largest species in the cat family, and the only wild cat with stripes in its fur. Up until the twentieth century, nine different subspecies of tiger roamed the earth, but with the extinction of the Caspian, Javan, and Bali tigers, only six subspecies remain. However, since most tigers are similar both physically and genetically, subspecies are commonly used only to designate a particular tiger’s geographic range. For example, the Sumatran tiger is found only on the Indonesian island of Sumatra.
A tiger’s body is built specifically for the hunt. Certain physical features allow them great advantageous when pursuing, catching, and then consuming its prey. A tiger’s large eyes gather more light than the eyes of other animals, and a special structure called the tapetum lucidum reflects this light, making objects appear brighter than they actually are. A tiger can turn its ears toward the source of a sound to enhance hearing sensitivity. While in pursuit of a smaller animal, a tiger can tighten its stomach muscles and bend its flexible spine like a bow, so when the muscles relax the spine snaps back into position with explosive force, hurtling the cat forward. It even uses its flexible tail as a rudder to aid in steering."