Heart rate (HR) responses to 3 different types of human stressors (sound, 10-m approach, and capture-immobilization) for king penguins brooding in areas of high (HD) or low (LD) human disturbance. (A) Excess HR is given in beats. (B) Relative maximum increase from resting HR (HRi) is given in percentage. Results are given as means ± SE. Statistics are figured for *p < 0.05, **p < 0.01, ***p < 0.001, n.sNon-significant.