The Bengal tiger is more vulnerable to extinction than previously thought due to a catastrophic decline in genetic diversity since the days of the British Raj when the tiger was hunted for pleasure. Since then it has dawned on people that the Bengal tiger reserves set up by India’s Project Tiger are too small to sustain a sufficiently large population. They are island reserves containing 20 – 120 tigers, which promotes tiger inbreeding. There have been discussions about this for many years and now it has come home to roost. Even when tigers are shipped from one reserve to another related tigers can be introduced and translocating felids is problematic. Then there is the poaching for tiger parts shipped to China together with encroachment by commercialism on these small reserves disturbing the tigers – there is some confusion in how to manage commercialisation of the tiger. This all combines to paint a black picture.
Simply breeding more tigers will not fix the problem. For every 100 variations of tiger in existence in the days of the British Raj just seven remain today. There are just two distinct genetic types of tiger in today’s Indian Bengal tiger reserves. One hundred years ago the tiger roamed across India largely unencumbered. The reserves just cut them off from each other. The impossible solution is to join the reserves together to enlarge them. The chances of that happening is next to zero.
The discovery of the sharp reduction in the Bengal tiger gene pool comes from doing DNA tests on old tiger skins and parts that were languishing in storage basements at the Natural History Museum, London and the National Museum of Scotland. Modern DNA testing has made significant advances allowing these old tiger body parts to be analysed.
Male wild cat roaming is good for genetic diversity. It is essential for genetic diversity. I was writing about this problem years ago:
- Male wildcat roaming opens new window -good for genetic diversity
- Inbreeding the curse of bigcats
- Inbreeding and sperm quality – inbreeding of big cats – problems
The Wildlife Protection Society of India spokesperson calls the reserves “pockets” and says that unless they are connected the Bengal tiger won’t survive.
Personally, my belief is that it is already too late because the gene pool is already too low. The Siberian tiger has the same problem. Although there are about 400 Siberian tiger in the wild, their breeding capacity is the same as 14!
Finally, counting tigers has always be problematic. We don’t really know how many Bengal tigers there are….