English: “To well understand all the ecological process that drive the physiology and behavior of animals in the nature, it appears really important to study organisms on the field. It is also important for the scientists to estimate our impact during study on the free living species. Here, we measured the heart rate (HR) excess (the number of heart beats produced in excess of resting HR due to different kind of stress: capture, 10 m approach or sound). To do this, we used an externally mounted-HR logger (Polar® model RS800) on a free long-lived seabird, the king penguin (Aptenodytes patagonicus). We compared the HR response due to the same 3 stressors between two parts of the colony: one disturbed by human presence and one without humans. We show that the HR response is lower for the bird in the non disturbed place, for 10 m-approach and sound stress, but there is no difference between the two places for the stress of capture. Habituation of the king penguin or selection of the bird who can support the human proximity? The picture was taken in Crozet archipelago (46°24′41″S ; 51°45′22″E ), a French island of the austral ocean ; the 13th February 2012. The experimenter was positioning the HR logger on the back of the king penguin.”