Why are Some Tigers White?
White Bengal & Siberian Tigers Exist in Zoos. How About the Wild?
Oct 5, 2009
White tigers are rarities, found in the wild only amongst the Bengal tiger (Panthera tigris tigris) population. They are not a separate sub-species of tiger nor are they albino tigers. True white tigers, sometimes called snow tigers, are Bengal tigers in all respects.
Most Bengal tigers live in India, but smaller populations can be found in Bangladesh, Bhutan, China, Nepal, and Myanmar. They inhabit both high and low-altitude climates, from thick forests on mountain foothills to grassland and mangroves.
Male Bengal tigers can be ten feet long (head to tail) and weigh up to 600 lbs. Females are approximately one foot shorter and weigh little more than half as much. Their tails can be three feet long.
Why are Some Bengal Tigers White?
White Bengal tigers get their coloration from a recessive gene. Most tigers exhibit the dominant gene, resulting in orange fur. To produce a white tiger, both parents must possess the recessive gene necessary for the white coloration. Even if one parent has white fur, its offspring will not have white fur unless its mate carries the recessive gene. It is the same with hair and eye color in humans; unless both male and female parents carry the recessive gene for blue eyes, their children have no chance of having blue eyes even if one parent does. Consequently, the recessive gene for blue eyes is also prevalent amongst white tigers.
But aren't Siberian Tigers White?
Siberian or Amur tigers (Panthera tigris altaica) are not white . . . in the wild, at least. These tigers are the largest of all big cats. According to Tigersincrisis.com, "[a]lmost all wild Siberian tigers live in the Southeast corner of Russia in the Sikhote-Alin mountain range east of the Amur River."
Because of their size, Siberian tigers are often bred with white Bengal tigers to create larger white tigers. Of course, the initial offspring of a Siberian tiger and a white Bengal tiger will be orange, but it may be larger and carry the recessive gene. Thus, breeding the offspring with a white Bengal tiger may produce a white Bengal-Siberian mix.
If White Tigers are So Rare in the Wild, Why are There So Many in Zoos and Circuses?
Simply put, a white tiger's coloration is both a novelty and a curse. Because of their beauty and appeal, white tigers are exploited. They are used by some zoos, circuses, stage shows, and the like to draw in crowds and to procure the almighty dollar. Many, if not most, are Siberian-Bengal mixes. The results of human greed to white tigers and the species as a whole have been disastrous.
According to Dr. Ron Tilson (as quoted by BigCatRescue.org), the Minnesota Zoo's Conservation Director and manager of the Tiger Species Survival Plan:
"[T]here is an unspoken issue that shames the very integrity of zoos, their alleged conservation programs and their message to the visiting public. To produce white tigers or any other phenotypic curiosity, directors of zoos and other facilities must continuously inbreed father to daughter and father to granddaughter and so on. At issue is a contradiction of fundamental genetic principles upon which all Species Survival Plans for endangered species in captivity are based. White tigers are an aberration artificially bred and proliferated by some zoos, private breeders and a few circuses who do so for economic rather than conservation reasons."
Inbreeding is rampant among captive white tigers. The lineage of all captive, American white tigers can be traced back to a few common ancestors, according to Exoticcatz.com. Per Big Cat Rescue, white tiger inbreeding results in many birth defects, still births, and early deaths.
On the other hand, zoos and "conservationists" who own white tigers argue that the tigers help increase public awareness of the plight of an endangered species. Undoubtedly, white tigers draw crowds, creating a forum for educating people about conservation issues.
Still, the benefits of massive inbreeding of white tigers seem outweighed by the detriments. Per Big Cat Rescue, "1 in 4 tiger cubs from a white tiger bred to an orange tiger carrying the white gene are born white, and 80% of those die from birth defects associated with the inbreeding necessary to cause a white coat." This high death toll does little to preserve any particular tiger sub-species or the species as a whole.
White tigers are beautiful, impressive animals worthy of preservation in their own right. However, where an entire species faces possible extinction, preserving a recessive gene of the most abundant sub-species should not be the focal point of tiger conservation.
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