A groundbreaking study by scientists has uncovered a troubling reality for elephants residing in highly fragmented landscapes, particularly those facing substantial human-caused disruptions. These magnificent creatures are exhibiting heightened adrenal activity, indicating severe stress, alongside reduced metabolic rates – a survival mechanism to conserve energy in increasingly difficult environments.
This crucial research, titled ‘Physiological responses in free ranging Asian elephant populations living across human-production landscapes,’ was featured in Scientific Reports, a respected journal from the Nature publishing group.
To conduct the study, a dedicated team of scientists and researchers analyzed physiological stress indicators in three distinct free-ranging Asian elephant populations: one in Central India and two in Northeastern India. Their method involved measuring faecal glucocorticoid metabolite (fGCM) levels for stress and faecal triiodothyronine (fT3) for metabolic states. These populations were chosen due to their differing levels of disturbance within human-modified landscapes.
Specifically, in the Central Indian region, the research focused on elephant populations within West Bengal’s Paschim Medinipur and Kharagpur forest divisions. In Northeastern India, observations were made on elephants inhabiting the Gorumara, Jalpaiguri, Jaldapara, and Buxa areas of the state.
The study explicitly highlighted that “elephants residing in the more fragmented Central Indian habitats displayed significantly higher fGCM levels and notably lower fT3 levels when compared to their counterparts in Northeastern populations. A similar trend of higher fGCM levels was also observed when contrasted with a previously studied Southern Indian elephant population.”
Sanjeeta Sharma Pokharel, the lead author, emphasized that while elephants might possess a degree of adaptability to human-altered environments, there’s a critical threshold of disturbance beyond which they experience extreme stress. Such prolonged stress can have severe physiological consequences for these animals.
Furthermore, the research indicated that aggressive human responses to elephant crop raids were most prevalent in the Central Indian population. Here, “hula parties”—groups of local residents attempting to deter elephants from human settlements in South Bengal—were noted for their particularly aggressive tactics. These groups are frequently criticized for using fireballs and torches to frighten the animals, methods that tragically sometimes lead to elephant fatalities.
The study also reported that negative interactions between elephants and humans, including unnatural elephant deaths and human fatalities from elephant attacks, were comparatively lower in India’s Southern landscapes than in the Central Indian region, particularly South Bengal.
The publication concluded, “Our findings reveal that elephants in the Central Indian population exhibited elevated fGCM and reduced fT3 levels compared to other populations. This strongly suggests a compromised health status for these elephants, likely due to their existence in severely fragmented habitats and the intense anthropogenic stress they endure.”
Renowned elephant ecologist Raman Sukumar, along with Amir Kumar Chettri, Sunipa Chatterjee, and Polani B. Seshagiri, also contributed to this significant paper. The researchers noted that previous studies on a southern elephant population had established a connection between lower fGCM levels and a higher quality diet among crop-foraging elephants. While a similar correlation was observed in the NE-1 and NE-2 populations, the Central Indian population showed a distinct deviation from this pattern.
Dr. Sharma Pokharel stated, “This suggests that severe human-induced disturbance, rather than just the quality of their diet, plays a more dominant role in triggering physiological stress responses in elephants.”
India is home to an estimated 27,000 to 30,000 free-ranging elephants, dispersed across four primary geographical zones: Northeastern, Northwestern, Central, and Southern. Each of these regions presents varying degrees of habitat fragmentation and levels of negative human-elephant interactions.
Southern West Bengal, a component of the severely fragmented Central Indian elephant habitat, is characterized by exceptionally high levels of conflict between elephants and humans. As elephant populations continue to grow, an increasing number of these magnificent animals are becoming “resident” in South Bengal, further exacerbating the challenges.