Female koalas more stressed than male counterparts

28 March 2023

Diseased or injured female koalas stress more than their male counterparts.

That’s according to recent research published in Veterinary Sciences journal, MDPI.

Led by CQUniversity koala researcher Dr Flavia Santamaria, faecal samples of 234 diseased, injured and control koalas were analysed.

“Using a koala-specific enzyme immunoassay called 50c as a non-invasive monitoring tool for the detection of faecal cortisol metabolites (FCMs), we were able to evaluate the impact of stress on hospitalised injured and diseased wild koalas ” Dr Santamaria explained.

The paper, titled, The Effect of Disease and Injury on Faecal Cortisol Metabolites, as an Indicator of Stress in Wild Hospitalised Koalas, Endangered Australian Marsupials found that while sick koalas stress more than healthy ones, females take on an even bigger emotional load than males.

“Diseased and injured koalas had significantly higher FCM values than clinically healthy control animals,” Dr Santamaria said.

“We also found that females showed a more elevated response to stress manifested by injury and disease.”

While it has been documented that habitat loss, urbanisation and climate change can cause stress in wild koalas, this latest research proves that they also stress when they’re physically compromised.

“Stress is associated with higher plasma cortisol levels, reflected in the faeces with an increased excretion of cortisol metabolites, hence, the aim was to determine if diseases and injuries, as well as hospitalisation, would increase FCM values in wild koalas,” Dr Santamaria explained.

“The faeces of diseased and injured koalas collected on day one showed altered values due to the prolonged pain that the koalas may have experienced prior to being admitted to hospital.”

This study is the fourth in a series that demonstrates the importance of using a targeted analytical tool to correctly assess stress in koalas.

The research has been made possible through close and extensive collaboration between national and international experts Dr Rolf Schlagloth (CQU), Dr Ludovica Valenza (Australia Zoo Wildlife Hospital), Professor Rupert Palme (University of Veterinary Medicine, Vienna), Dr Deidre de Villiers (Endeavour Veterinary Ecology) and Professor Joerg Henning (University of Queensland).