There is a proposal that the number subspecies of tiger should be reduced because it would make it easier to protect this now relatively rare and endangered species of wild cat from becoming extinct in the wild.

South China tiger in captivity

In general terms the experts are saying that there are too many tiger subspecies because the difference between the subspecies is too small and therefore you could reduce the current number of living (extant) subspecies, which is six, to a more manageable and pragmatically useful two.

It should be said that the science of classifying animals into species (taxonomy) has always been somewhat flexible. Some would say it is almost arbitrary. It just depends upon what the scientist decide is a subspecies and how different an animal needs to be to become a species or subspecies. If the difference between, for example, a Sumatran tiger and a South China tiger is less, at a genetic level, than the difference between a person from Ireland and a person from India, should they be classified as different subspecies?

A study published online decided that there is “little variation and large overlaps in each trait among… tiger subspecies”. The study suggested that only 2 subspecies should be recognised: the Sunda tiger and the “Continental tiger”. The Continental tiger consists of 2 units, one in the north and one in the south. The distribution (where they are found) of the “Continental tiger” is from Russia to Southeast Asia. The other proposed subspecies which is located in the Sunda Islands is part of Indonesia and in between the Malay peninsular and Australia.

If the idea of reducing the number of tiger subspecies is adopted then conservation would become easier because you could bolster low populations of tigers in a certain area with tigers from an entirely different area and which would otherwise be classified as a different subspecies. Until now it was considered as unacceptable to cross breed different subspecies of tiger because you would create a hybrid and you would reduce the genetic purity of the subspecies.

Tiger with Prey. Photo by Bharat Bolasani

In addition, there are a considerable number of purebred tigers in captivity around the world although the last majority are what is called generic tag (hybrids or “moggie Tigers”). Some of these captive tigers could be used for genuine conservation purposes. At the moment is not possible to employ them as part of a conservation programme in part because of the current classification of subspecies.

I don’t think it is that shocking an idea to re-evaluate the number of subspecies of the tiger because, as mentioned taxonomy, the classification of the species of the world, can take any form that people want it to take. Whether we wish to define any animal of the same species as different to another simply because there is a very small difference in their DNA is up to us. We can ignore that small difference and call them the same subspecies. Indeed, we could ignore large differences if we so wish and do away with subspecies. It is really arbitrary although scientists like to refine their work and have probably inflated the number of subspecies over the years because it suits them (the ‘discovery’ of a new subspecies improves their CV).

As the pressure mounts to protect the endangered tiger, the idea proposed in this article becomes more attractive to conservationists. The policy of injecting fresh genes from another subspecies (as classified) has occurred with respect to the Florida panther. Eight female Texas cougars (a different subspecies) were introduced into Florida in 1995, which has helped to alleviate inbreeding and therefore improve the survivability of the Florida panther (also a cougar or puma). The same sort of thing should happen to the tiger, it is argued.