Cubs regularly fed dumped carcasses grew up as scavengers: Study

Placing baits in the tourism zone of Gir National Park, Gujarat, to increase visitors’ chances of viewing Asiatic lions can disrupt their behaviour and social organisation and have a detrimental effect on the density of local prey, says a study by Wildlife Institute of India (WII), Dehradun.

The four-member WII team, which experimented with a new mathematical model they developed, to estimate the population of Gir’s lions, observed that cubs regularly fed with dumped carcasses grew up as scavengers.

As a result, younger lions lacked the predatory skills required to hunt when they dispersed from the tourism zone, often trying to kill livestock – the easier prey – and coming in conflict with humans.

This finding is in line with previous studies that baiting disrupts lion behaviour and social dynamics.

The study ‘Spatially explicit density and its determinants for Asiatic lions in the Gir forests’ was published in the open-access journal PLOS ONE on Thursday.

The study was conducted within 725sqkms of the western part of the Gir Protected Area covering the entire tourism zone – 1.2 million tourists visit annually – and about 30% of the national park. Other aspects such as prey density and factors that could influence lion density was also assessed.

To improve assessments, the WII team used vibrissae (whisker) patterns and permanent body marks to identify individual lions via a computer program – as opposed to the traditionally ‘total counts’ method employed for the last 40 to 50 years to estimate lion population.

“Asiatic lions are an icon of conservation success, yet their status is inferred from total counts. An alternative method could provide accurate estimates of their abundance. We have developed a modern scientific peer-reviewed method for counting animals, which is acceptable worldwide,” said Yadvendradev K Jhala, principal investigator and senior a biologist at WII.

Ravi Chellam, a wildlife expert and chief executive officer, Metastring Foundation in Bengaluru said, “Currently a significant number of lions are either wholly or partially living outside the boundaries of the protected area and in human-dominated landscapes. Estimating lion population outside the protected area may require a modification of the method described in the publication.” Data analysis using the new polygon search-based spatially explicit capture recapture (SECR) framework identified 67 individual lions out of 368 lion sightings estimating an overall density of 8.53 lions per 100sqkms.

Lion density was higher in flat valley habitats closer to human habitations as against rugged or elevated areas. Reason: In order to minimise predator movements near the hamlets and villages along the close periphery of the Gir PA, park rangers collected livestock carcasses and moved them to specific locations within the tourism zone – or baiting sites – to attract lions and maximise sightings for tourists.

As a result, lion density increased near baiting sites and decreased with increasing distance to the tourism zone. “Such animals that lack skills to hunt often come in conflict with humans…and can also become a danger to human lives,” the study states.

WII is currently in dialogue with the Gujarat forest department to use this methodology to count lions in a scientific manner. “There is a proposal pending with them to use our expertise to help them in the next count. It’s now up to them Gujarat forest department to use this methodology,” said Jhala.