Credit: US Weekly

(Phys.org) —Koalas can become stressed by noisy and up-close encounters with human visitors, a University of Melbourne study has determined.

The koala is a much-loved Australian icon and extremely popular with foreign tourists, but little work had been done to understand how they cope with human interaction.

Dr Jean-Loup Rault from the University's Animal Welfare Science Centre said researchers set out to answer this question.

"Our study showed that up-close and noisy encounters with human visitors resulted in koalas showing so called 'increased vigilance', which is a common response to stress."

"Stress is generally an energy-costly mechanism. This could be a problem as koalas survive on an extremely low energy diet—largely made up of Eucalyptus leaves—and minimize energy expenditure by sleeping 20 hours a day."

Researchers tested the effect of visitor numbers, visitor noise, and visitor proximity on koalas at the Koala Conservation Centre, which forms part of the Phillip Island Nature Parks network.

"This work also highlights the value and importance of behavioural observations as a monitoring tool to assess visitor-related stress in koalas" according to Zoo's Victoria's Sally Sherwen, a collaborator on the study.

The research raises questions about the classic trade off between visitor education and animal welfare.

"Some wildlife parks offer close encounters or even hands on experiences with koalas," said Dr Rault.

"Only now are we beginning to understand the impact of these visitor encounters on ' behaviour and welfare."

More information: Megan J. Larsen, Sally L. Sherwen, Jean-Loup Rault, "Number of nearby visitors and noise level affect vigilance in captive koalas," Applied Animal Behaviour Science, Volume 154, May 2014, Pages 76-82, ISSN 0168-1591, dx.doi.org/10.1016/j.applanim.2014.02.005.

Journal information: Applied Animal Behaviour Science