SYDNEY, Sept. 19 (Xinhua) -- An Australian researcher has resolved why gorillas in Rwanda have been venturing out of their protected jungle habitat to chow down on nearby plantations of Australian eucalyptus trees.
Cyril Grueter from the University of Western Australia told Xinhua on Wednesday that the sodium-rich eucalyptus bark presents a salty treat that despite the risks, the gorillas seem determined to pursue.
Grueter, a primate specialist who spent two years monitoring the gorillas in Rwanda, said that while getting up close with our evolutionary cousins was unforgettable, the research was demanding.
"We actually had to work really hard in the forest, we had to collect data following a very strict protocol -- we were interested in basically how much food the gorillas consume everyday," Grueter said.
"So what we did is we basically observed them and we counted the number of food items that they put in their mouth."
Monitoring the gorillas food intake led Grueter and his colleagues to observe the primates seeking plantations of eucalyptus, outside of the protection of their home in Virunga National Park, placing them at increased risk of coming into contact with humans.
"They go after eucalyptus, they strip off the bark and they eat it -- and they seem to love it a lot," Grueter said.
"So we took some samples to the lab, we did nutritional analysis and we found that Eucalyptus bark is extremely rich in sodium -- about 100 times richer than what's found inside the park where the gorillas normally live."
The gorillas appear to be seeking the salty bark in addition to their dietary requirement, similar to how humans enjoy sodium-rich foods like potato chips or soy sauce.
"I don't think they really need the eucalyptus, it's just that now it's there and it's attractive so they go after it," Grueter said.
Similarly, "we would be perfectly fine without salty chips right? But since it's there and you can buy it in every local grocery store, we go for it -- same with the gorillas."
And it's not primates alone in the animal kingdom who go to extreme lengths to satisfy cravings for salt.
"If you look at other animals, elephants sometimes go deep into caves to find salt licks and every animal has a different strategy to make sure that it gets enough sodium and now the gorillas have this unusual strategy, they just raid eucalyptus plantations."
Grueter hopes the findings of the study will advance the discussion of how to adapt local human land use to effectively curb conflict with the salt-hungry gorillas.
