Little penguins do not habituate to routine interactions with humans

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Research perspective written by Gemma Carroll
Department of Biological Sciences, Faculty of Science and Engineering
Macquarie University, Sydney, Australia

How can I explain the importance of this research to the general public?

Interactions between humans and wildlife for research and ecotourism can have many benefits, such as gathering information that can assist with conservation and raising public awareness. Scientists and the general public often assume that these kinds of interactions are not very stressful for the animals involved. This is true in many cases: if the activities are well regulated, some animals can become habituated when they realise that humans do not pose any serious threat.

In this study, researchers investigated the stress response of the world’s smallest penguin species: the little penguin. They captured penguins and kept them outside their nest for 30 minutes. Every 10 minutes, they assessed the penguins’ behaviour and measured the levels of stress hormones in their blood. The researchers found that penguins that had regular contact with humans as part of an eco-tourism and monitoring program actually had a more severe stress response than penguins that had never encountered humans before.

These unexpected findings show the importance of trying to measure the impacts that human activities have on animal behaviour and physiology. This information can help us to maximise the positive outcomes from wildlife conservation initiatives, while finding ways to minimise the risk of harm to sensitive animal species.

Why is this important for researchers in fields other than ecology?

This study revealed that a small seabird, the little penguin, did not habituate to routine interaction with humans. Rather, penguins exposed to both research and ecotourism mounted a heightened physiological and behavioural response to stress compared with naïve penguins. These unexpected findings emphasise the importance of quantifying the impact of human activity on wild animal populations, especially when an activity is conducted long-term and is assumed by researchers and/or managers to be relatively benign. This study suggests that by identifying species that are sensitive to disturbance, researchers can determine whether changes to research and tourism protocols to make them less invasive may be appropriate to alleviate stress.

Why is this important for researchers in the same field?

This study demonstrates that little penguins ([:em “Eudyptula minor”]) exposed to ecotourism and routine handling by researchers had elevated levels of circulating plasma corticosterone and more aggressive behaviour during a stress protocol than naïve penguins. First, the penguins’ natural stress response to 30 minutes of capture was described at a control site where penguins had never encountered humans. These results were compared with the stress responses of (a) penguins that were routinely captured on their nests and weighed for monitoring, and (b) penguins that were captured and weighed less frequently, but were also observed by tourists each night. Penguins with a history of exposure to either type of human activity appeared to be sensitised rather than habituated to disturbance based on both physiological and behavioural indicators.

Original article

Prior exposure to capture heightens the corticosterone and behavioural responses of little penguins (Eudyptula minor) to acute stress
 Gemma Carroll, Emma Turner, Peter Dann, Rob Harcourt
Conservation Physiology, published online 15 November 2015

Acknowledgements

This work was supported by Macquarie University. The original text was published by Oxford University Press and the Society for Experimental Biology.