Physiological and reproductive consequences of human disturbance in Humboldt penguins: The need for species-specific visitor management

Over the last decade the Humboldt penguin, Spheniscus humboldti, has become a focus for ecotourism. Current management applies visitor guidelines similar to those developed for Magellanic penguins, Spheniscus magellanicus. However, unlike these, Humboldt penguins are extremely sensitive to human presence. Breeding success was significantly reduced at frequently visited sites. Heart rate telemetry during disturbance experiments revealed that Humboldt penguins respond more strongly to human presence than do any other penguin species thus far studied. A person passing an incubating penguin at 150 m distance already provoked a significant heart rate response. Recovery times were up to half an hour after direct human approach, causing increased energy expenditure without any overt behavioural reaction. Being extraordinary sensitive to human activity with little habituation potential the Humboldt penguin proves to be a difficult focal species for ecotourism. For sustainable ecotourism visitors are required to stay out of sight of Humboldt penguin breeding and moulting areas. Management guidelines need to acknowledge that even closely related species may react very differently towards human presence.