Indian scientists develop new, improved method to survey lion populations

An alternative method for monitoring endangered lions in India could improve estimates of their abundance, according to a study which may help inform conservation policy and management decisions.

The researchers, including Keshab Gogoi from the Wildlife Institute of India, said conservation practices have enabled Asiatic lions to recover from a population of only 50 individuals in the Gir Forests of Gujarat, India, to an estimated 500 individuals today.

However, according to their study published in the journal PLOS ONE, accurate estimates of their abundance are needed in order for conservation efforts to remain successful.

The researchers said that existing monitoring methods, particularly a technique known as total counts, can miss some individuals while double-counting others, and they provide limited information on spatial density.

In the current study, Gogoi and his colleagues demonstrated an alternative method for monitoring Asiatic lions using whisker patterns and permanent body marks to identify individual lions using a computer program.

The researchers also assessed prey density and other factors that could influence lion density.

In the study, the researchers identified 67 individual lions out of 368 lion sightings within a site of 725 square kilometers in the Gir Forests in Gujarat, estimating an overall density of 8.53 lions per 100 square kilometers.

They found that prey density did not appear to influence variations in lion density within the study site.

On the contrary, the study noted that lion density was higher in flat valley habitats, as opposed to rugged or elevated areas, and near sites where food had been placed to attract lions for tourists to view them.

According to the study's findings, baiting lions for tourism greatly perturbs their natural density patterns, in line with other studies showing that baiting disrupts lion behaviour and social dynamics.

The authors suggest that their alternative monitoring method could be used to assess lions across their range in order to inform ongoing conservation efforts more accurately.

"The only population of Asiatic lions in the world survives in the Saurashtra landscape. Conserving this sub-species with the use of best science and management is a global priority and responsibility," the researchers said.

Our research paper addresses this priority by developing a robust approach to their population assessment and monitoring which can be used for all lion populations across the world," they added.