Tuesday, March 27, 2007

White Tigers and the Conservation Question

So...we've covered the basic genetics of color heritability in tigers, and now you are probably wondering where I am going with this all. Well, a little more story-telling first. Remember Mohan? He was the male white Bengal tiger captured in the 50s. There were reported sightings and even shootings of white tigers before him, but he was the first one caught alive, that we know about. As the story goes, his mother and 2-3 siblings (depending on the account you read) were shot by the Maharajah at the time, but Mohan the Cub, escaped. Fascinated by the idea of catching a white tiger, the Maharajah sent dozens of people out into the jungle to round the cub up. Long story short, he was captured and taken to the Maharajah's palace where he lived out his days in relative captive luxury.

But it certainly wouldn't do to just have one white tiger. More white tiger cubs clearly needed to be created! To do this, the Maharajah bred Mohan to a wild-caught female Bengal of normal coloration, getting a litter of cubs with the typical orange and black look. However, banking on the idea of simple dominant-recessive inheritance of color in tigers (though it hadn't been described as such, yet), the Maharajah then bred Mohan to one of his daughters. Voila: he got some white tiger cubs!

And it is certainly easy to see the fascination with white tigers. They are stunning animals with that brilliant snow-white fur that contrasts so perfectly with that unique pitch-black striping and those ice-blue eyes that look right through you. It is easy to see why a group of them would certainly be an impressive sight, and why they would be a desirable addition to any one's magic routine.

The problem is they are a man-made species. All white tigers of today can be traced back to Mohan and, consequently, all are highly inbred. It is an example of inbreeding, a relatively common practice in the animal world. Closely related animals are bred in the hopes of magnifying and perpetuating a desirable trait. Inbreeding has been used to develop virtually every domestic dog, cat, horse, cow, pig, bird, goat, sheep, rabbit, etc, breed that there is. Unfortunately, while this type of breeding may intensify the desirable traits that are being bred for, it will also magnify the bad traits. Highly inbred animals tend to have a much higher rate of genetically-related deformities and faults. White tigers are especially inbred since there are so few of them and Mohan is essentially the only foundation animal. In the white tiger, common birth defects include everything from crossed eyes to arched backs to a weakened immune system.

Another problem is that most white tigers are "mutts." The original white tigers have been crossed with Siberians, Indochinese, Sumatran and other tiger species so much that it is difficult to say with certainty what species many individuals are. Interestingly, the highest incidence of birth defects is now seen in white tigers that are Siberian/Bengal crosses of on sort or another while the Bengal whites tend to be healthier. Many would have you believe that white tigers are some unique, exceptionally rare species which is clearly not the case at all. In essence, white tigers are to other tigers what the bulldog is to the wolf.

So, here is the basic gist of the issue: the white tiger is a man-made phenomenon. The goal of conservation is to maintain species in as close to their natural form as possible and there is a very limited amount of money and resources to do that. Conservationists would like to see all that money go to preserving the various tiger species in their natural form. However, the white tiger is stunning! The white tiger is beautiful! The white tiger is mysterious! People love white tigers! People are much more excited about seeing a white tiger than they are with the "run-of-the-mill" orange and blacks. And, consequently, they are more likely to donate money to an institution that has white tigers. I don't have any actual figures to back it up, but just ask any zoo director or curator. They'll tell you the same story.

So, what is a conservationist to do? It grates against the very fabric of their being to devote precious time, energy, resources, and space to this genetically worthless, messed up creature. Many hardcore conservationists argue that the breeding of tigers for the express purpose of perpetuating the white mutants should be stopped, and the thought certainly has merit. On the other hand, the funds and interest that the white tigers bring in is certainly nice, and could be applied to other species as well. But does the end justify the means? Is it fair to keep white tigers only because they are a money-maker?

That question is the heart of the matter, and it is one that gets anyone in the zoo world fired up. If you want to have a passionate debate about conservation, just start talking about white tigers. Ultimately, each institution makes its own decision about whether or not to keep white tigers. I can tell you, of the 30-odd tigers that are here, 4 of them are white Bengal tigers (3 females and 1 young male).

But, "come on," you say ,"are they really that much more popular than the other tigers? They are beautiful as well." They certainly are. But nearly every time I have walked through the cat house in my 5+ weeks here (which is almost every day), the biggest crowds have been watching the white tigers.

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