A long-standing intervention by the Assam government to reduce crop depredation by elephants in its forest areas, piloted and designed by the environmental NGO World Wildlife Fund (WWF), is actually linked to more accidental elephant deaths, a study in Conservation Biology has reported.
Launched in 2003 in Sonitpur district, Assam’s Anti-Depredation Squads (ADS) coordinated with local villagers and the forest department to patrol their fields and drive away elephants en masse. The aim of the units was to find safety in numbers for people while preventing direct conflict that could result in elephant trapping or poaching. Versions of this kind of protection exist all over the world.
Assam expanded its ADS presence in 2008 and continues to field new units today. They are part of the official national guidelines for dealing with human-elephant conflicts and are also present in West Bengal, Odisha and Chhattisgarh. And 2019 review Of the various ways people can respond to human-elephant conflicts, the Union Environment Ministry noted that ADS operations “were not systematic” and that “local mobs” shooting at elephants reduced their effectiveness.
Using 20 years of data on elephant deaths in Sonitpur, mapped along with the presence of ADS in villages in the area, the study found an almost 2-3x increase in accidental elephant deaths associated with villages that had ADS compared to villages that did not. The elephants did not die as a result of direct conflict with villagers, but were found in ditches or trenches, electrocuted, or swerved into the paths of oncoming trains. The study revealed no detectable impact on human mortality.
Nitin Sekar, lead author of the study, said the results contradicted their original hypothesis: “We were all prepared for the evidence to show no effect on mortality. We had hoped it would reduce mortality in humans and elephants. But this was a surprise.”
Mr. Sekar started the analysis when he was the National Head of Elephant Conservation at WWF-India with the idea of statistically determining the impact of ADS. He is now a director at Conservation X Labs.
E. Somanathan, a professor in the Department of Economics and Planning at the Indian Statistical Institute in Delhi and head of the Center for Research in Climate, Food, Energy and Environmental Economics, designed the statistical analysis in the study. He said the increase in deaths, while statistically significant, may not be directly evident to people on the ground who believed the intervention had reduced both elephant and human mortality.
“The whole purpose of the WWF-India intervention is conservation, so they didn’t expect this,” Mr Somanathan said.
While the team was prepared for the data not being good enough to draw one conclusion or the other, they didn’t expect the actual findings.
“It’s a 200% increase in deaths due to elephant conflicts,” Mr Somanathan said. “Doubling or tripling is a big effect. The number is big enough to warrant a careful examination of the program. The people who drive away the elephants need to take a second look. The program should think carefully about how it’s done.”
Although the study began in 2019, the authors added several controls to their data to account for other mitigating factors, leading to a longer time to publication.
‘It raises more questions’
The paper said: “Although this finding contradicts one of the hypotheses on which the ADS program is based, it is consistent with the concerns of several human-elephant conflict experts.”
However, Pranav Chanchani, head of species conservation, and Aritra Kshettry, national head of elephant conservation at WWF-India, cautioned that the link between elephant deaths and ADS actions is tenuous.
Villages in Sonitpur district selected as population of interest for the study. | Photo credit: DOI: 10.1111/cobi.70204
“The ADS study found a strong link between the ‘presence’ of ADS and elephant mortality data, and therefore raises important questions about prevailing human-elephant conflict management strategies,” Mr. Chanchani and Ms. Kshettry wrote in an email.
“But there are also several key gaps in the ADS study that limit direct attribution or causal inference, so the study probably raises more questions than it answers.”
Organized surveillance
Assam is home to more than 5,000 wild elephants, the second largest population of large mammals in India. Sonitpur, in north-central Assam, is part of one of the five priority landscapes for elephant conservation identified by the Elephant Working Group in 2010 – and is home to about 1.9 million people.
When WWF conceived ADS in 2003, Mr. Chanchani and Ms. Kshettry said there was already a decade-long history of lost forest cover. Elephants displaced from their habitats began to move through cultivated areas, tea plantations and the banks of the Brahmaputra river, among others. They were harassed and persecuted by the locals, leading to higher mortality rates for both. WWF believed that if ADSs organized guarding activities, it could reduce overall elephant mortality instead of leaving communities to fend for themselves.
ADSs have formed in villages where there have been recent incidents of crop raiding, prompting the community to team up with the widely distrusted forest department to jointly respond to elephants. Each ADS had 10-15 male volunteers who were given searchlights and firecrackers to keep the elephants at bay. Officials of the department cooperated with the ADS and used information from them to drive the elephants out of the fields.
But according to a new study, the sound and light may have created what it called a “landscape of fear,” causing elephants to lose their caution and wander into more dangerous situations.
“Although caution is warranted given the modest sample sizes and uncertain quality of postmortem data in the region, these findings suggest that in communities with ADS, elephants may have been less likely to notice a danger such as a ditch, kill wire, or an oncoming train because they were too frightened or distracted by pursuers (or perhaps even because they were more likely to pursue them).”
However, Mr Chanchani and Ms Kshettry also warned that while the elephant mortality data was taken from many years, ADS are only active during harvest season, meaning some deaths may have been wrongly attributed to ADS activity. They also said the study had no ground truth.
A villager tries to drive away a herd of wild elephants resting in the Bholaguri tea garden in Sonitpur district, September 2014. | Photo credit: RITU RAJ KONWAR
Development of controls
The study used 20 years of data collected by the WWF-India ground team in Assam and human and elephant mortality data by the forest department. Since the hypothesis was that ADS would reduce elephant mortality, scientists tried to rule out many alternative explanations.
An agricultural area in a village attracts elephants more because it might seem to offer more nutrition than foraging in forest areas. Taking this into account, the study could explain whether there was a higher than usual presence of elephants in the area. The second and third variables were the fraction of the area around the village composed of elephant habitat and changes in the distance from the village to areas accessible to elephants on elephant movement trails. The study also took into account the increase in human population and the intensity of lighting at night, a common indicator of the extent of development.
The researchers also took other variables into account. For example, ADSs are likely to have started in villages where there has been recent conflict. Since human or elephant deaths are not that common in these events, another incident immediately after the ADS launch would be unlikely because it would have just happened. This could be interpreted as a result of ADS itself.
In the analysis, the team therefore excluded the year of ADS onset and the two previous years from the comparison with mortality in years with active ADS. When they found that the result was an increase rather than a decrease in elephant deaths, they also excluded only the year in which ADS was established from the comparison with mortality in years with active ADS. The result was similar, explained Mr. Somanathan.
Another bias they addressed was underreporting—due to the poor relationship villagers typically had with the ministry. As the ADS corrects these links, it could be that there were the same number of deaths and that more were now officially counted. When the study included control for potential underestimation bias, there was still an overall increase in elephant mortality associated with ADS.
Due to a lack of data, the study was unable to explain whether ADSs were able to protect more crops than before.
Pause and check
As anti-robbery squads proliferate in India, the study raises serious concerns about the effectiveness of such interventions — and raises questions about why the finding wasn’t revealed earlier.
“We are talking about 14 more deaths in as many years,” Mr Sekar said. “ADS are active moons continuously for many years. The only way you can find this connection is through statistics. It seems highly unlikely to me that anyone in the field could detect this effect.”
Both Mr. Sekar and Mr. Somanathan called for a review of this and other interventions to reduce human-elephant conflict, including electrified fences and the use of sound and light in innovative ways.
“This is a good example of why we need more assessments,” Mr Sekar said. “We should not rapidly expand an intervention without evaluating its effect. In general, it is also ideal not to make any major policy decisions based on one study. The best next step would be rapid and rigorous evaluation of ADS by other groups.”
Mr. Chanchani and Ms. Kshettry agreed that more study is needed — while noting that ADSs are also constantly evolving to meet ground needs.
“We believe it will be prudent to pursue a strategy in which ADSs adaptively refine their actions, particularly in relation to pursuit,” they wrote. “Unless there are data to the contrary, we believe it is unlikely that the alternative (unorganized pursuit) will have better outcomes for humans and elephants.”
Mridula Chari is a freelance journalist based in Mumbai.
