The Wildlife Conservation Society (WCS) India Program published the results of its study in the May edition of Biological Conservation, an international journal published from the US. The study, called Reliable monitoring of elephant populations in the forests of India: analytical and practical considerations also reviewed common methods used to estimate elephant numbers in India.

Conservationists and wildlife experts DevcharanJathanna, UllasKaranth, Samba Kumar, Varun Goswami, DivyaVasudev and KrithiKaranth led the study conducted by WCS, a non-governmental organization.

Unscientific counting methods can throw up wrong figures, harming conservation efforts. More accurate methods are used to count India’s tiger populations, but the rigour has been lacking when it comes to the elephant, declared India’s national heritage animal in 2010. In the same year, India’s Elephant Task Force had called for discarding methods used to monitor many elephant habitats, since they are not rooted in modern animal sampling and estimation theory.

The study cautioned elephant researchers against sources of bias and imprecision in usual methods. “A sound understanding of the distribution and abundance of a species is a prerequisite for devising appropriate policies at the national level and for implementing on-ground conservation actions at the level of each reserve,” said Dr K. UllasKaranth, director of science in Asia, WCS, and a co-author of the study.

The study advocated using sighting-based line-transect sampling method to estimate reliable numbers of elephants. It also said this method helps researchers understand the patterns of elephant abundance over time and space.

“Under this method, two survey personnel walk along pre-marked transect lines counting elephants and also recording simple additional information such as distances and compass bearings of the observed animals from their survey lines,” explained the study.

Using this method, the study estimated elephant population densities in Bhadra, BiligiriRanganatha Temple, Bandipur and Nagarahole Tiger Reserves in Karnataka. The results showed a range of densities from an average of 0.3 elephants per sq. km in Bhadra to 2.2 elephants per sq km in Nagarahole.

“This approach, if replicated, can result in crucial information on the population status, strengthening elephant conservation in source sites across India,” a WCS statement said.

“We believe it is practical to implement line transect surveys in many of the elephant reserves in the country, where accurate estimates of elephant population size are important for conservation planning and action,” said DevcharanJathanna, lead author of the study in the statement.

Several methods such as dung estimation are currently used to count elephants, said Sandeep Kumar Tiwari, deputy director at Wildlife Trust of India, a non-profit organization. “These methods are good enough, provided the procedures are implemented well. But there could be more robust methods,” he added.

Experts believe that reliable monitoring of key elephant populations has assumed great significance in the light of increasing poaching pressures, loss of forests, fragmentation and deterioration of remaining habitats.

Also, around 400 people and 100 elephants are killed in human-elephant conflicts every year in India, according to environment ministry estimates.

The International Union for Conservation of Nature has estimated the global population of Asian elephant, an endangered species, at 41,000-52,000. According to India’s environment ministry, the elephant population in 2012 was 29,300-30,700. This makes India the home for over half of the entire estimated Asian elephant population.