The mountain gorillas of Rwanda are leaving protected areas to raid crops, endangering the lives of the already vulnerable animals.
Rwanda's Mountain Gorillas Craving For Sodium
Scientists at the Dian Fossey Gorilla Fund's Karisoke Research Center and the Max Planck Institute wanted to understand why the popular mammals are escaping from the national park, where there is food available to them, to agricultural plots. It turns out that the gorillas are venturing out of safety to munch on eucalyptus, which is a hundred times richer in sodium.
The team monitored the sodium intake of 22 gorillas from three social groups for one year and measured the sodium content of 34 items from the gorillas' main diet. They found that two-thirds of the gorillas' sodium intake comes from eucalyptus.
Sodium plays an important role in the body, particularly in the nerves and muscles. According to the U.S. Dietary Guidelines, human adults need less than 2.3 grams of sodium per day in order to avoid health complications.
The mountain gorillas, one of the closest living relatives of humans, also need sodium in their bodies to function properly.
The scientists could not say whether the animals are leaving protected areas to get their daily dose of sodium or for any other reasons. They proposed that the gorillas might also be stealing eucalyptus for medicinal purposes. The study also found that they also target giant groundsels and lobelias, both of which are also rich in sodium.
Conservation Of Mountain Gorillas
The findings are important because mountain gorillas remain vulnerable. The mammals were nearly wiped out in the 70s because of poaching and loss of habitat. While the population was able to bounce back due to conservation efforts, only around 1,000 mountain gorillas exist in Virunga Volcanoes and in the Bwindi National Park in Uganda to date.
If the mountain gorillas continue to leave their safe haven to steal crop, the locals might become hostile to the animals, making conservation efforts more challenging. The scientists also warned that close contact between animals and humans might lead to disease transmission.
The team sees two possible ways to discourage the mountain gorillas from raiding agricultural crops for sodium.
"To discourage the gorillas from crossing into farmlands near the forest, there may need to be a change in agricultural practices such as relying less on plants sought by gorillas for their nutrients," Cyril Grueter, one of the authors of the study, wrote.
"An ideal scenario would be to establish a buffer zone containing nutritionally unattractive and unpalatable plants. If sufficiently wide, it would discourage gorillas from crossing into croplands."
The findings appear in the journal Biotropica.