When animals interact in 'benign' ways with humans, they may let down their guard," Blumstein said. As animals get used to feeling comfortable with humans nearby, they may become bolder in other situations, he says. "If this boldness transfers to real predators, then they will suffer higher mortality when they encounter real predators."
Eco-tourism is in some respects similar in this regard to domestication or urbanization. In all three cases, regular interactions between people and animals may lead to habituation--a kind of taming. Evidence has shown that domesticated silver foxes become more docile and less fearful; a process that results from evolutionary changes but also from regular interactions with humans. Domesticated fish are less responsive to simulated predatory attacks. Fox squirrels and birds that live in urbanized areas are bolder. It takes more to make them flee