Heart rate responses to induced challenge situations in greylag geese (Anser anser).

Abstract

Adequate short-term responses to stressors are of great importance for the health and well-being of individuals and factors modulating the physiological stress response (e.g., controllability, suddenness, familiarity) of a stimulus are well described under laboratory conditions. In the present study we aimed at investigating the stress response in greylag geese (Anser anser) in the field, confronting individuals with naturally occurring stressors. We measured beat-to-beat heart rate (HR) via fully implanted transmitters during three different experimental challenges: (1) catching and holding, (2) confrontation with a model predator, and (3) approach by different humans. We compared this to a control period and HR during agonistic encounters, a naturally occurring stressor. All three experimental situations evoked a HR increase. Highest HR responses were elicited by catching and holding the animals. In the third experiment, HR responses were greatest when the geese were approached by a human stranger (i.e., somebody the geese have never seen before). Hence, geese discriminated between different kinds of stressors and adjusted their physiological response depending on the type of stressor. Our results show that geese were able to discriminate between individual humans. In line with a number of lab studies, we suggest that particularly the controllability of certain situation determines the intensity of the HR response, also in a natural setting in the field.

Monitoring the wild black bear's reaction to human and environmental stressors

“…We thus suggest that ICMs may be a useful addition to the burgeoning field of conservation physiology [34]. New devices, applications, and procedures for heart rate monitoring will continue to advance the growing body of literature investigating effects of human activities and other environmental stressors on wildlife [35-40]. …”

Modulation of heart rate responses to acute stressors throughout the breeding season in a colonial seabird, the king penguin

“…For instance, we recently found that the HR response of colonial king penguins (Aptenodytes patagonicus) to acute experimental stressors increases with stressor intensity (Viblanc et al, 2012). Similarly, several studies have documented stimuli-dependent modulations of HR responses to stress in other species Tarlow and Blumstein, 2007;Wascher et al, 2011), including other penguins (Giese, 1998;Holmes et al, 2005;Ellenberg et al, 2006Ellenberg et al, , 2013. To our knowledge, however, whether acute stress responses are modulated according to lifehistory stages in interaction with stressor intensity is unknown.…”

Coping with continuous human disturbance in the wild: insights from penguin heart rate response to various stressors

“…Distant approaches occur when scientists/tourists observe birds from the edges of the colony, whereas a limited number of captures are performed annually by scientists for research. HR provides a highly sensitive measure of stress responses, that may be modulated independently of hormonal pathways [37] and allow greater insight than hormonal responses (such as corticosterone) on how stress responses are shaped depending on the specific nature of various stressors [37,38]. Using this method gave us the possibility: (i) to investigate how stress responses were shaped by chronic exposure to humans, and (ii) how this shaping might have varied according to stressor type and intensity, and potential risk for the animal.…”