New research by scientists at The University of Western Australia has solved the mystery of why critically endangered mountain gorillas go to extremes to raid eucalyptus plantations.
Gorillas in Rwanda’s Virunga Mountains have long been observed exiting their natural park refuge and gorging themselves on eucalyptus bark on community land, resulting in human-wildlife conflict. They also sometimes climb to the top of volcanoes to eat eucalyptus trees, where they face cold stress.
Now scientists have worked out why. It is to satisfy the need for salt in their diet.
Lead author Dr Cyril Grueter from UWA’s School of Human Sciences and the Centre for Evolutionary Biology said the study found eucalypts were more than a hundred times richer in sodium than the gorillas’ staples inside their park, and this was the main incentive for the gorillas’ escapades.
“The gorillas obtain up to two thirds of their sodium when consuming eucalypts,” Dr Grueter said.
“A sodium deficit can trigger a specific hunger for it which causes animals to do all sorts of crazy things to get it.”
It is hoped the findings of the study will advance the discussion of how to adapt local human land use to effectively curb conflict with salt-hungry gorillas going on crop raids.