Currently there are 3,890 tigers in the world, according to the World Wildlife Fund. Our neighbouring country India has the largest tiger population now – 2,226. Bangladesh is ranked seventh in number of tigers with 114 in the country. The tiger population in India was 1,411 in 2006 and it increased to 1,706 in 2010 and according to the census of 2014, the number was 2226. In Nepal, the number of tigers was 121 in 2009, which has almost doubled in 2018, standing at 235. But in Bangladesh, the number dropped to 106 in 2015 from 440 in 2004. The number grew by only eight from 2015 until now.
Various factors such as free movement of people in the Sundarbans, tiger-human conflict, a drop in the number of deer and other food sources, and also scientifically genetic reasons have been blamed for Bangladesh’s failure to increase the number of the big cats.
There has been no genetic variation in reproduction as the number of tigers in the Sundarbans is limited. Meanwhile, the limited number of tigers in the Sundarbans has increased the probability of inbreeding that leads to the release of a type of deleterious gene, which increases the possibilities of maternal and infant mortality. In addition to the management of human and natural causes, it is important to think seriously about the genetic and related issues and to bring about the genetic variation to this animal which remains in danger of extinction. Increasing heterogeneity by genetic variation can be expected to increase tiger numbers. But how can we increase heterogeneity of tigers in the Sundarbans?
The effective method may be reintroduction. In this method, under the supervision of experienced experts, selected tigers from different sources like zoos and safari parks are mated, thus increasing the number of tigers by reproduction. And after training, these tigers at first are released in a semi-wild environment, restricting them to the place for observation, before being released to the wild. Several countries have undertaken the reintroduction program.
But only bringing genetic diversity will surely not be enough. The other long-term steps to save the tigers can be:
=> Banning public entry in the Sundarbans completely while removing and rehabilitating the residents of the forest through the launch of bee, livestock and fish farming around it along with small area- or household-based biogas plants.
=> Establishing deer and pig farms and release these in the forest to ensure supply of tigers’ food.
=> Keeping sources of water for tigers safe by preventing pollution and river encroachment.
=> Compensating the families of those killed and injured in tiger attack to avoid mob beating of the animal.
Md Shahadat Hossain is a deputy curator at Chittagong Zoo and Md Tariqul Islam Anik is the production officer at Chittagong Veterinary and Animal Sciences University.