Today’s Wonder of the Day was inspired by Caidence from Bakersfield, CA. Caidence Wonders, “Why are some tigers white?” Thanks for WONDERing with us, Caidence!
When you hear the word "tiger," what do you think of? For most people, an image of a giant cat with orange and black stripes probably comes to mind. These apex predators are as fierce as they are beautiful.
If you've ever seen illusionists Siegfried and Roy's Las Vegas show or visited certain zoos, though, you may envision a different, more unique tiger: one that's snow white with black stripes. White tigers are exceptionally rare and exotic. But what exactly are they and where do they come from?
Some people claim that white tigers are a special subspecies of tiger that's endangered and dangerously close to extinction. While white tigers are indeed rare, they're not a separate subspecies and they're not albinos. Moreover, most, if not all, of the white tigers alive today were purposefully bred by zoos and private collectors.
White tigers are Bengal tigers that have two copies of a very rare recessive gene that controls coat color. Specifically, researchers have discovered that white tigers are caused by a single gene mutation in the protein known as SLC45A2.
White tigers can occur naturally in the wild, and there are reports that a few were seen in the tropical forests and jungles of India and Southeast Asia in the early 20th century. The last known wild white tiger was shot in 1958.
Today, white tigers exist only in captivity in zoos, wildlife sanctuaries, and private collections. Experts believe that all of the white tigers alive today are probably descended from the same male white tiger cub that was captured in 1951.
Because of their beauty and rarity, white tigers have become very popular attractions at zoos and wildlife sanctuaries. For years now, zoos and private collectors have purposefully inbred white tigers to multiply their numbers. White tiger cubs can be sold for $30,000-$60,000 or more.
Unfortunately, deliberate inbreeding to create white tigers has led to a white tiger population that's often affected by a variety of health problems. For example, white tigers are often cross-eyed and have trouble with vision and depth perception. Other common health problems include kidney problems, club feet, shortened tendons, cleft palates, and scoliosis of the spine.
In 2011, the Association of Zoos and Aquariums banned all its member zoos from breeding white tigers. However, now that the specific gene mutation that produces white tigers has been identified, some people want to continue to breed white tigers since it could potentially be done without inbreeding and the resulting health problems that are so common.