For the traveler hoping to catch a glimpse of African gorillas, an ecotourism trip -- often billed as a low-impact trek that supports conservation -- might seem like the ideal vacation. But a new study has found that ecotourists cause distress among wild apes, putting the animals at risk for stress-related disease.
The key to understanding ape anxiety, it turns out, lies buried within the animals' poop. A group of European researchers collected gorilla feces from a forest in the Central African Republic to measure stress hormones in the excrement. By comparing different groups of gorillas -- some that frequently encountered tours, others that never met humans -- the scientists found a link between stress and tourism.
Gorillas that never encountered tourists had the lowest levels of stress hormones. But when humans visited the wild gorilla bands, the apes' hormone levels shot up -- particularly within the first two weeks of contact.
Stress levels also spike when tourists get too close to apes. Although ecotours have adopted regulations meant to keep humans at least 20 feet away from gorillas, the rule often goes flouted, as this close encounter shows. Widening the buffer zone between ape and tourist -- and enforcing it -- will keep these endangered primates calm and healthy, scientists say.