Short- and long-term changes in the intensity of responses of pinnipeds to tourist approaches in Cabo Polonio, Uruguay

Wildlife watching has become an important constituent of commercial tourism, and opportunities to encounter wildlife have proliferated and diversified. After regular tourist visits to a wildlife population, the intensity of behavioural responses to tourist approaches is expected to change due to diverse mechanisms, including habituation, sensitisation, social learning and population displacement. The village of Cabo Polonio (Uruguay, 34°24′S, 53°46′W) is small, but in summer, there is a massive influx of people, with more than 30 000 tourists entering Cabo Polonio in January alone. The rocky cape of Cabo Polonio is a haul-out site mainly occupied by South American fur seal (Arctocephalus australis) males and South American sea lions (Otaria flavescens). No monitoring or guided tours occurred at this continental colony. We examined changes in the intensity of behavioural responses of pinnipeds to tourist approaches at two temporal scales: (i) throughout a season, by comparing results from spring 2014 and summer 2015, and (ii) throughout the years, by comparing data from spring 1996 with those from spring 2014. We found that peopleś attitude and distance of approach influenced the animals' behaviour. The responsiveness of the pinnipeds almost tripled after two decades. We propose that the fence built in 1997 to protect the colony produced a paradoxical effect: instead of reducing the disturbance produced by tourists, it appears to increase it. This decrease in tolerance of tourism throughout the years goes against the argument that animals habituate to human presence after long-term exposure.