Are negative effects of tourist activities on wildlife over-reported? A review of assessment methods and empirical results

There is a general assumption that animal species that face anthropogenic disturbance through tourism suffer some negative impacts as a result. We carried out a meta-analysis of empirical studies of wildlife responses to tourism activities in natural areas to test this assumption. A literature review yielded effect size data for 102 studies representing 99 species. We compare and contrast different measures of response to tourist activities (avoidance responses, time budgets, and physiological responses). Despite most authors interpreting their data as revealing negative impacts of tourist activities on wildlife, we found that behavioural data (flight responses and time budgets) often indicated positive effects of such activities; time budget data are often ambiguous, while physiological data tended to show negative responses. Therefore, how researchers measure the responses of animals, how they interpret the valence of these responses, and the timescale of measure are all important considerations. For example, different measures of physiological response may indicate short term coping responses, while there may be long term physiological change that could influence population dynamics, often beyond the scope of the study. Many species are also able to mitigate the effect of tourist disturbance through habituation and moderation of short term responses, such as avoidance/fleeing responses. In conclusion, therefore, although there could be long term consequences to tourist activities, these impacts are often not readily measurable. Greater consideration of assessment methods to quantify such effects is warranted.