But while their money helps pay for conservation, these “invasive” trips often do more harm than good because they “domesticate” local animals, putting them at greater risk of being eaten, research says.
By posing for snaps, swimming with dolphins and generally winning the trust of the animals they encounter, the tourists inadvertently put wild creatures in danger by encouraging them to relax with other humans – and, in turn, natural predators – who might not be so friendly, the study finds.
Gorillas, jackass penguins and wild Barbary macaques are among the species most susceptible to ecotourism because they have a strong tendency to “habituate”, or relax, in the presence of humans.
“When animals interact in ‘benign’ ways with humans, they may let down their guard,” said Professor Daniel Blumstein of the University of California in Los Angeles.
“As they get used to feeling comfortable with humans, they may become bolder.
If this boldness transfers to real predators, then they will suffer higher mortality.
” Blumstein says ecotourism is similar to domesticating or urbanising the animals – in all three cases, regular interactions with people might lead to a kind of taming.
Gorillas and other animals can “let down their guard” when they spend time around humans.
Evidence has shown that domesticated silver foxes become more docile and less fearful, in part due to regular interactions with people.
Meanwhile, domesticated fish are less responsive to simulated predatory attacks and fox squirrels and birds that live in cities are bolder and take more time to flee from danger, he says.
With 8 billion ecotourism trips now taking place around the world each year, a phenomenon that aims to act sustainably by helping support the economies and wildlife they encounter can be added to the list of “drivers of human-induced rapid environmental change”, Blumstein said.
Other examples include climate change, the destruction of habitat and intensive farming.
But apart from raising money for conservation and local communities, ecotourism does have another benefit, says the report, which is based on an analysis of more than 100 studies into its effect on wildlife.
The presence of humans can discourage natural predators, creating a kind of safe haven.
When humans are around, vervet monkeys have fewer run-ins with predatory leopards.
And in Grand Teton National Park in Wyoming, elk and pronghorn in areas with more tourists spend less time on alert and more time feeding, the report notes.
But to what extent do these more relaxed and bolder behaviours around humans transfer to other situations, leaving the animals at risk in the presence of their natural predators – and of poachers? “We know humans are able to drive rapid phenotypic (personality trait) change in other species,” says the report published in Trends in Ecology & Evolution.