Previous experiences with humans affect responses of Snares Penguins to experimental disturbance

Abstract

Historically, little contact with humans makes the Snares Penguin, Eudyptesrobustus, an ideal species to study the natural response of penguins to human proximity. We measured behavioural and heart rate (HR) responses of Snares Penguins to a range of stimuli commonly occurring at their breeding sites and to experimental human disturbance. While behavioural responses gave an indication of disturbance effects, measuring HR provided a more objective and reliable tool to evaluate a stimulus. Natural stimuli usually caused little HR increase and were followed by rapid recovery. An experimental human approach provoked a significantly greater HR increase than most natural stimuli and more time was needed to recover from this disturbance event. Simultaneous and previous research projects on the Snares Penguin provided an opportunity to test the effects that contemporary experience with humans had on the Snares Penguin stress response. Penguins undisturbed in this study but exposed to intrusive research and filming activities the previous season showed significantly stronger responses to human approach than did naive birds. Hence, individual experiences with humans may have lasting effects on stimulus-specific disturbance responses.