We humans are stressing out elephants, a study of wildlife at Serengeti National Park in Kenya and in Grumeti Game Reserve and Ikoma Open Area in Tanazania has found. Scientists discovered that elephants who stayed within the protected areas’ boundaries were less stressed than those who ventured beyond their borders.
There are no fences or barriers separating the preserves from adjacent lands so the elephants can roam in and out.
To determine stress levels, scientist measured levels of the stress hormone gluccorticoid in the animals’ dung. Samples inside the preserves revealed lower levels, while those taken outside the park had higher amounts. Elephants who ventured out of protected areas — perhaps for something tempting to eat — were most likely more stressed because of encountering more cars and other vehicles.
Even more, elephants outside protected areas show more stress because they have come to associate motor vehicles with people and hunting. As research team member Dr Eivin Roskaft of the Norwegian University of Science and Technology in Trondheim explains to the BBC, the reason the elephants exhibit higher stress is “probably that [they] try to avoid human-elephant interactions. Elephants probably remember where they are, and that bad experiences stress them.”
An earlier study has found higher levels of stress in elephants who leave preserves to eat farmers’ crops. Just the thought of coming in contact with humans who are very likely to be hostile is stressing out elephants.
Roskaft hopes to use the study results to help in the ongoing fight for elephants’ survival in Africa. With human development, and hunters, encroaching ever nearer the borders of parks, elephants have more reason to be anxious than ever.
Not only does the study, which is published in the African Journal of Ecology, show the extent to which human activity is deeply felt and experienced by animals. It also reveals (once again) that elephants never forget. When it comes to the species who is after them for their meat and ivory tusks, the memories are stress- and fear- inducing. Besides building roads and cutting down forests, we humans have left an invisible mark on wildlife and not one with pleasant associations.
Considering that, due to humans, some say that elephants in African could be extinct in ten years — Roskaft says this could happen even in five or six years — it’s hardly a surprise that Africa’s elephants are showing very, very clear signs of stress. If the thought of an elephant-less Africa worries you, we need to (in Roskaft’s words) ensure that “the world … find interest” in such a terrible prospect that, not too long ago, would have been unthinkable.
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