Study questions tiger conservation efforts

Recent conservation efforts by the government of India may suggest that tiger numbers are recovering. However, population of tigers remain fragmented.

A joint study has come out with an interesting analysis on the tiger population in India that gives a different take on tiger conservation. The study by the group of scientists asks: "Is the population recovery sufficient for population persistence?"

The study calls for the application of evidence-based demographic and genetic management to enhance the remaining populations as a priority. Small fragmented population of tigers would not help, as inbreeding would ultimately genetically weaken the species making them susceptible to illnesses.

The study highlights that insights into past population and genetic processes can help guide conservation, and re-iterates the importance of museum collections in such research. This study is an international collaboration between the National Centre for Biological Sciences and Cardiff University, funded by the National centre for biological sciences (NCBS), department of science and technology and the Royal Society International programme.

"We know that population size has declined in the last two hundred years. But is numbers of tigers all that we have lost? We investigated this question using genetic data from tigers in the past. We did this by extracting DNA from museum specimens of tigers, which were between 50-200 years old. These specimens were mostly from the London Museum of Natural History. We compared the genetic data from these skins to those from existing tigers," said the study.

Tigers now occupy less than 7 per cent of their historical geographic range. The subcontinent harbours 50-60 per cent of the global population, and our earlier research has shown that Indian tigers harbour 60-70 per cent of the global genetic variation, hence holding a key to tiger conservation.

The study asked if genetic variation in tigers in historical times (100-200 years ago) is different from animals today. The available data reveal high variation in historical times, most of which (93 per cent) seems absent in extant (existing) populations. More importantly, modern tigers are genetically more disconnected than historical populations for multiple genetic markers. Increase in population disconnectedness, as seen with tigers, can be a conservation red flag for the species, it added.

The scientists suggest protecting some populations, at the expense of losing others, is an inadequate conservation strategy, as it could result in loss of genetic diversity that may be of adaptive significance for this emblematic species.