|King penguin. |
A team of researchers from the University of Strasbourg, the Centre National de la Recherche Scientifique (CNRS) and the University of Lausanne compared 15 king penguins breeding in areas disturbed daily by humans and 18 penguins breeding in undisturbed areas. The penguins in the study were all brooding a chick aged from 2 days to 1 month.
Using heart rate to indicate the stress level of each penguin, they compared the stress response of penguins from the different areas to three stressors. Two low intensity stressors, a human approach to 10 metres and a loud noise, mimicked the actions of tourists, researchers, and noises from machines when operating on the outskirts of the colony. One high intensity stressor, a capture, simulated researchers taking measurements.
Compared with penguins from undisturbed areas, penguins from areas of high human disturbance were less stressed by noise and approaching humans. However, following capture, the maximum relative heart rate of the penguins who were used to humans increased 42% higher than it did for undisturbed birds, although the human-acclimated penguins then recovered faster. Therefore, penguins seem to be getting used to human observers, but they do not habituate to being captured.
“Our findings report a case of physiological adjustment to human presence in a long-studied king penguin colony, and emphasise the importance of considering potential effects of human presence in ecological studies,” said lead author Vincent Viblanc.
While penguins getting used to people may be beneficial to scientific research and tourist management, this study also raises the question of the potential influence of human activities on the selection of specific phenotypes (traits). For example, could human disturbance cause those individual animals who are more stress-sensitive to progressively leave the disturbed areas? For scientists studying animals in their native habitat, it also underlines the importance of physiological studies in interpreting results before conservation measures are implemented.
Evaluating the impact of humans on protected wildlife such as king penguins is particularly important given the rise in popularity of Antarctic tour groups. Dr Viblanc said that a central question for ecologists is the extent to which anthropogenic (i.e. human) disturbances such as tourism might impact wildlife and affect the systems under study.
"One of the major pitfalls of such research is in forgetting that, from the perspective of the wildlife studied, tourism and scientific research are not two worlds apart," he said.
Not so happy: king penguins stressed by human presence, 11 July 2012, BioMed Central
BMC Ecology citation
Coping with continuous human disturbance in the wild: insights from penguin heart rate response to various stressors. Vincent A Viblanc, Andrew D Smith, Benoit Gineste and René Groscolas, BMC Ecology 2012, 12:10 doi:10.1186/1472-6785-12-10