Stressed Out: Koalas Can't Bear Humans

It seems that koalas can't bear us. The furry animals 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 tourist attraction, but "koala encounters" offered by zoos down under could be leaving the animals stressed out.

Until now, little work had been done to understand how they cope with human interaction.

"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," Dr. Jean-Loup Rault from the University's Animal Welfare Science Centre said in a news release.

"Stress is generally an energy-costly mechanism," he added. "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."

The University of Melbourne study 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 behavioral 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.

Now that researchers are aware of the negative effects humans can have on the adorable animals, it raises questions about what kind of balance can be struck between visitor education and animal welfare.

"Some wildlife parks offer close encounters or even hands on experiences with koalas," Rault added. "Only now are we beginning to understand the impact of these visitor encounters on koalas' behavior and welfare."

The findings, entitled "Number of nearby visitor and noise level affect vigilance in captive koalas," is published in the journal Applied Animal Behavior Science.