The white tiger is a visually arresting animal, often leading to confusion about its status in the wild. People frequently mistake it for a separate, highly endangered species. Understanding the white tiger requires looking beyond its striking appearance to the science of its coloration and the consequences of its captive history.
Defining the White Tiger
White tigers are not a distinct species or subspecies of tiger, but rather a rare color variation, or color morph, of the Bengal tiger (Panthera tigris tigris). They are occasionally found in the Siberian tiger population. The distinctive white fur with dark stripes results from a genetic mutation that naturally occurs within the Bengal tiger gene pool, affecting only the coat pigmentation.
Since they are genetically Bengal tigers, white tigers do not require a separate conservation status. While the Bengal tiger is listed as Endangered by the IUCN, the white color morph does not signify a greater degree of endangerment. The lineage is not extinct, but the visible manifestation of the white coat is now practically absent from nature.
The Genetics of the White Coat
The unique white coloration is caused by leucism, a naturally occurring genetic mutation that reduces the red and yellow pigment pheomelanin. This differs from albinism, which is the complete absence of all pigment and typically results in pink or red eyes. White tigers retain dark stripes because the mutation does not significantly affect the production of black pigment. Their eyes are typically blue, and their stripes are dark brown or black.
The white coat results from a recessive gene that must be inherited from both parents. Scientists identified a point mutation in the SLC45A2 transport protein gene, which affects the pigmentation pathway. A tiger will only be white if it possesses two copies of the recessive allele (‘ww’). For two orange tigers to produce a white cub, both must be carriers of this recessive gene, a combination that occurs naturally only about once in every 10,000 tiger births.
Population Status in the Wild and Captivity
The white tiger is considered effectively absent from its natural habitat today, leading to the common misconception of its extinction. The last verified sighting of a free-ranging white tiger occurred in 1958, when an individual was shot in the Satgangwe Forest Range in India. Before this, white tigers were occasionally documented in the wild, particularly in the central Indian states.
Virtually all of the several hundred white tigers existing today are found in captivity, housed in zoos, private collections, and wildlife parks worldwide. This entire captive population descends from a single male white Bengal tiger named Mohan, captured in 1951. Because the recessive gene is rare, breeders relied on intensive and repeated inbreeding to consistently produce white offspring. This practice preserved the white coat trait but disconnected the lineage from the wild population and its natural genetic diversity.
Ethical Concerns in Breeding Programs
Selectively breeding tigers for their white coats has raised ethical concerns due to the health consequences of forced inbreeding. To ensure the recessive white gene is passed on, closely related tigers, such as father to daughter or brother to sister, are often mated. This deliberate reduction in genetic diversity amplifies the expression of harmful recessive traits.
The result is a high incidence of severe health issues in captive white tigers. Common defects include spinal deformities (such as scoliosis), defective organs, immune deficiencies, and optic nerve damage resulting in crossed eyes. Many cubs born from these pairings do not survive. Because the white tiger serves no purpose in the conservation of wild Bengal tigers, their breeding is often viewed as a commercial enterprise prioritizing aesthetic appeal over animal welfare.