Abstract
Increasingly, seabirds nesting on islands are exposed to tourists who view, photograph, and study, them for variable periods of time. The escalating frequency of human-seabird contacts on heretofore undisturbed nesting islands raises questions and concerns about the effects of human disturbance, and of the continued preservation of nesting colonies of marine birds. We examined short-term changes in behaviour of Masked (Sula dactylagra), Redfooted (S. sula), and Blue-footed (S. nebouxii), boobies when tourists walked by, and examined display station and nest placement as a function of distance from a regularlytraversed tourist path on Tower (Genovesa), Hood (Espanola), and North Seymour, Islands, Galápagos. Whether displaying boobies walked, flew, or remained on their station, when tourists passed, was related to their distance from the trail. Boobies displaying at stations on or up to 2 m from the trail, walked or flew from their station 62 to 95% of the time, depending on the species. All species of boobies performed more head and body turns, and gave-out more calls, after tourists passed than before, while the rate of preening did not differ. All three species of boobies avoided nesting right along the trail, despite similarities of habitat. These data suggest that boobies respond to tourists in subtle ways often related to their species, and that further studies should delineate impacts operating over longer periods—including reproductive success variation as a function of disturbance.