We humans don’t just stress each other out, sometimes elephants too are affected by our activities. And signs of this stress have been found in what might seem like a rather unlikely place—their poop!
Wildlife habitat everywhere is shrinking, and India is no exception—forests are being converted to places that aren’t as welcoming towards their wild inhabitants any longer. In these changing times, elephants in our country are increasingly finding themselves restricted to smaller, fragmented habitats within larger human-dominated ones.
This is a significant change from their old, large, native ranges, where they roamed relatively freely in. Quite naturally then, this is making many of us wonder how our elephants are doing.
Loss of habitat, amongst other factors, pushes elephants to enter areas they previously avoided—areas where humans live in large numbers. And as these interactions between elephants and us increase, instances of conflict do too—and sometimes with serious consequences for both us and these pachyderms.
Unpleasant interactions drive elephants to either adapt to the changing climate, or be pushed out of that habitat altogether. But apart from serious consequences like crop damage and loss of human and elephant lives, conflict has other less-visible effects on elephants too—one of which can be found in their poop.
NCF’s Sreedhar Vijayakrishnan, M Ananda Kumar and adjunct faculty Anindya Sinha, along with two researchers from other organisations, set out to find how this transition in their habitat is affecting elephants by studying stress hormones in their faeces. This study was carried out in the Valparai plateau—a place in the Anamalai Hills of the Western Ghats in India.
They studied stress levels in sixty-nine individual elephants that were part of both crowded and relatively-undisturbed habitats on the Valparai plateau—and here are some of the things they found:
Stress levels in elephants were different depending on their age and sex—adults and males had larger concentrations of the stress hormone in their poop than juveniles and females. This is perhaps because, authors say, adult elephants are more aware of the risks involved in living in close proximity to crowded places.
They found that after an aggressive drive, the magnitude of increase in stress levels was much higher in calves.
“This seems to tell us about the role of experience in coping with stressful situations,” says Sreedhar Vijayakrishnan, the lead author of this study.
Surprisingly, though, there was no significant difference in stress levels between elephants in crowded parts of the plateau, and those in adjacent relatively-undisturbed forest habitats. Hmm. So yay! Erm… we aren’t really stressing them out, right?
“Although we found no significant difference in stress levels between elephants in crowded parts and those in forests, drives—where elephants were driven away aggressively by people—did increase stress in those individuals. Elephants are highly wary of interactions with humans. They often stay alert and adopt behavioural strategies such as becoming nocturnal to avoid getting into such interactions.
However, often, such interactions are inevitable, and to avoid conflict situations, elephants are driven from anthropogenic spaces.
During such drives, elephants huddle together to form a social buffer. Another typical response is to flee from the drives.
These behavioural responses are followed by physiological responses in the form of heightened stress hormone (fecal glucocorticoid metabolite) concentrations,” explains Sreedhar.
“These drives often last for a few days. Such prolonged drives could lead stress hormone concentrations also to remain consistently high, switching from what could be defined as an acute stress response to chronic stress.
It is known from studies on various taxa that consistently high levels of stress could prove detrimental to bodily processes such as immune responses, digestion, and reproduction.
Stress, technically, is defined as a response to a stressor, by regulating aforesaid processes. When these mechanisms are shut down for prolonged periods, that questions their survival,” he adds.
If we take a look around, we can see that so much is changing in the natural world. We know this well, we watch it on the news, we read it on our Twitter feeds. And apart from the more obvious ones, there are several seemingly tinier changes too—ones that we may miss, if we don’t look close enough.
Although normal amounts of stress is essential for the survival of any species (humans included), sudden drastic rises in stress levels in elephants caused by aggressive interactions with us, could perhaps have consequences that are extremely drastic, even though they aren’t obvious to us at first.
Says Sreedhar, “To understand potential impacts of stress on the general health of the animal, especially in the case of long-lived animals such as elephants, it is vital to have long-term monitoring of their populations.
It is only through long-term monitoring that one can understand how individuals and populations adapt to changing environments in terms of their behaviour, physiology, and demographic parameters.”
Deeper research into understanding how what we do affects other species has never been more important than it is today—not just for the well-being of these gorgeous animals we share our planet with, but for ours too.
Read the full paper here!
And here’s a brief note by the authors.
- Sreedhar Vijayakrishnanan, Mavatur Ananda Kumar, G. Umapathy, Vinod Kumar, Anindya Sinha
(2018). Physiological stress responses in wild Asian elephants Elephas maximus in a human-dominated landscape in the Western Ghats, southern India. General and Comparative Endocrinology (2018).
Photos: Sreedhar Vijayakrishnan
Video: A baby elephant and her mother that Sreedhar shot during fieldwork in Valparai: