Transgenerational Consequences of Human Visitation

Human interactions with wild animals may result in changes in behavior across generations with consequences for population trends and hence threat status. Exposure to humans and tameness of animals when exposed to humans may also imply significant costs such as the rapid spread of viruses and other microorganisms that constitute reservoirs or vectors of serious diseases. Ecotourism and nature-based tourism are factors that may affect the behavior of animals living in natural habitats, including their stress and fear responses. Here I review a scarce and scattered literature dealing with changes in animal behavior across generations and critically assess the relative importance of the mechanisms that potentially underlie these changes. Animals may show short-term changes in behavior across generations as a consequence of microevolution (a genetic change in behavior), nongenetic so-called epigenetic changes, reductions in the response to behavioral stimuli with repeated exposure to a stimulus (habituation), and the nonrandom distribution of animals that differ in behavior among sites (so-called phenotypic sorting). I conclude with a plea for future research to allow assessment of the underlying causes of long-term changes in behavior of animals exposed to human disturbance, particularly those changes caused by ecotourists’ activities.