Nairobi, Dec 16 – As the human-elephant conflict continues to rise across Africa, researchers are searching for new ways to keep a watchful eye on wild African elephants, even looking to space for guidance.
In the rural community of Sagalla, which is adjacent to Tsavo National Park in Kenya, and is a hotspot for crop-raiding elephants, researchers at Save the Elephants and the Department of Biology at the University of Oxford have, for the first time ever, tracked the minute footprints of elephants using a high-resolution hand-held Garmin GPS that captures point to point fixes at every 3-5 seconds, and overlaid it with free high-resolution satellite imagery to identify how plant diversity on a micro-scale affects elephant movement.
In the process, discovered that elephants make considered decisions about which paths to take based purely on their favourite food. The findings recently published in the Remote Sensing journal may be critical in helping conservationists forecast potential human-elephant conflict (HEC) hotspots.
The Sentinel 2A imagery – obtained through an open-source satellite managed by the European Space Agency, has enabled scientists to map every single piece of vegetation within each 10m pixel in and around Sagalla. While elephants are normally tracked at 1-hour intervals, the handheld satellite GPS captures all the twists and turns, every thorny thicket, and every tree that an elephant would take on its chosen path. The elephant data from the study covers the period from January 2015 to 2020.
The results show that bull elephants prefer to walk paths that have or lead to plants called Combretum and Cissus which are only eaten by bulls. Family groups will walk paths with Commiphora and Terminalia, which are dietary preferences for family groups comprising females and young calves. Furthermore, when the two groups combine and move together, they choose paths that have or lead to areas where both preferred delicacies are available, in other words ensuring there’s something for everyone.
The study is important because understanding how elephants access their favourite vegetation could help conservation managers focus resources on potential conflict hotspots outside protected areas and better protect plant diversity within parks and buffer zones. Mapping the location and composition of specific vegetation species within plant communities also helps scientists to better understand the impact of human encroachment and vegetation removal on elephant movement.
“It is incredible the level of detail we can infer from free satellite imagery about the processes that control the spatial dynamics of elephant movements,” said lead author Gloria Mugo. “A lot is known about what kinds of foods are eaten by elephants, however, being able to single out the fact that their movements can be driven by their fancied, gender-based diet, helps to further our understanding of micro-level ecological interactions.”
Key findings
- Free high-resolution satellite imagery is helping researchers identify how plant diversity on a micro-scale affects elephant movement
- The findings show that elephants make considered decisions about which paths to take based purely on their favourite food
- The findings may be critical in helping conservationists forecast potential human-elephant conflict (HEC) hotspots when favourite plants overlap with human settlements.
