White tigers are a sub-species of Bengal tiger, with pigmentation that makes their fur white instead of orange. Male Bengal tigers range from 400 to 550 pounds in weight, but white tigers are often bigger and heavier. The inbreeding of captive white tigers creates a number of genetic defects.
Although the fur color of white tigers is due to a lack of yellow and red pigments, they are not albinos. Some white tigers have an orange tinge to their white or cream-colored fur. Their stripes are dark brown or black. They have pink noses and paw pads, and their eyes are usually blue but sometimes amber or green. Females are smaller and lighter than males.
The white coloration occurs in cubs only if both parents carry the distinctive gene necessary. This happens rarely in nature, and the several hundred specimens of white tiger in captivity are results of breeding within the captive white tiger population. One of the most common genetic deformities of white tigers is crossed eyes. Other physical deformities include twisted necks, crooked backbones, club foot, shortened foreleg tendons, cleft palates, kidney problems and mental disabilities. In July 2011, the Association of Zoos and Aquariums banned white tiger breeding by its member zoos in an effort to curb genetic defects.