Effect of touristic activities on seabirds' habitat selection on sandy beaches

Seabirds are biological models for habitat selection studies at different spatial scales. In general, seabirds select areas with a higher availability of prey, but human disturbances can modify their spatial and temporal foraging patterns in urban coastal ecosystems. Here we tested the hypothesis that human activities prevent seabirds foraging on beach sectors that are impacted by urbanization and recreational activities. Seabirds were counted while foraging at the interface between the surf zone and foreshore in three sectors with different levels of urbanization in southeastern Brazil. Physical variables, prey abundance, and human stressors, such as the number of people and dogs, were also measured. The brown booby Sula leucogaster foraged mainly in the least impacted sector, despite the lower abundance of prey and harsher physical conditions. The number of individuals of this species was negatively related to the number of people, indicating a human-induced avoidance behaviour. In turn, the kelp gull Larus dominicanus, a synatropic species, was more abundant in the high impact sector. Our results have implications for the management and conservation of sandy beaches, especially regarding the zoning and selection of priority areas for environmental protection and nature-based ecotourism activities.

Automated summary

Seabirds are affected by human activities in urban coastal ecosystems, with brown boobies preferring less impacted beaches and kelp gulls adapting to highly urbanized sectors.