One of the biggest concerns of conservationists when dealing with endangered species and reducing habitats is the viability of the gene pool. If species don’t get the chance to meet and breed within the wider population then their future survival is reduced.
Scientists have used the latest genetic techniques in India to show that despite habitats becoming increasingly fragmented and the journey between each habitat becoming increasingly hostile territory the tigers are finding their way around and meeting up for breeding.
Non-invasive DNA studies benefits tiger conservation.
The researchers were able to recover DNA from droppings left by tigers to understand the family history and genetic diversity of tiger populations in the Central Indian landscape. The new techniques offer a new tools for conservation management and monitoring of one of the worlds most loved endangered species.
The study looked particularly at the tiger populations in the Ranthambore Tiger Reserve (RTR) – an isolated tiger forest in north-east India – and other local isolated wildlife parks; Kuno-Palpur Wildlife Sanctuary (KPWLS) and Madhav National Park (MNP).
Healthy gene flow from Ranthambore Tiger Reserve.
The researchers discovered that despite the tiger reserve and parks being fragmented and degraded there was a healthy flow of genetic material between the Ranthambore Tiger Reserve and the other two parks. There was also evidence of first generation migrant tigers moving from Ranthambore to both Kuno-Palpur and Madhav NP.
With tigers moving out of the Ranthambore the researchers concluded that the tiger reserve had reached it’s natural carrying capacity and new generation tigers were actively looking to extend their range.
The significant gene flow between the sub populations within and outside the Ranthambore Tiger Reserve also indicated that despite the hostile environment between parks the tigers were successful in moving around and finding mates.
Tigers overcome a hostile environment to meet up.
The area surrounding the Ranthambore Tiger Reserve is highly degraded in respect of tiger habitat. Much of the land between the reserves and parks have been converted over to agriculture and human habitation and commercial/industrial uses. The poverty in the region means that tiger poaching is also high. Despite these handicaps tigers have succeeded in moving along the few corridors that remain.
Being able to monitor the movement of tigers and the mixing of genes within the population is an essential tool if the tiger is to survive in India. Of 150 tiger reserves on the Indian sub-continent it is estimated that only 21 of them have the potential to sustain a ‘gene healthy’ population. The remaining tiger reserves rely on sub populations being able to mix in order to keep a strong gene pool.
Reassessment of tiger populations.
The genetic testing also led to a revision of the number of tigers living in one of the areas looked at. Previous indirect estimates had put the number of tigers in a 3,000 km2 landscape at 3 but the genetic testing showed at least 4 different tiger individuals living in the landscape.
Extra conservation measures needed to protect tiger corridors between wildlife parks.
The team are now calling on the two states that cover the three reserves - Madhya Pradesh and Rajasthan – to put in place stronger cross-territory conservation efforts to ensure that the corridors used by the tigers remain viable. At the moment the connecting corridors between the three wildlife parks examined have the least conservation protection and are at high risk of being lost to development.
The team from Centre for Cellular and Molecular Biology, Hyderabad, India also called for the Madhav National Park to be redesignated as a tiger reserve as it has the potential to support a breeding tiger population. They also recommend that Kuno-Palpur Wildlife Sanctuary is specifically surveyed for a resident tiger population as it has suitable habitat and prey for the park to be more than just a stop over on a transit route for tigers.