Why aren’t koalas suitable as pets?

Volume 10 Number 7 July 14 - August 10 2014

 

Andi Horvath finds out why koalas are better off left alone, protected from habitat loss and other harmful human interventions.

Wildlife surveys have driven the decision to list Australia’s favourite icon, the koala, as vulnerable in several states and territories (Qld, NSW and ACT). 

So could we embark on a civic duty program to adopt these cute, cuddly, sleepyheads into our backyards and local reserves? Unfortunately for us, the science says no.

Dr Kath Handasyde from the Department of Zoology has been researching the ecology, management and diseases of Australian native mammals for over 35 years, and says, fundamentally, the reason koalas aren’t suitable as pets relates to issues of diet.

“Unlike our urban brushtail possums, which have a flexible diet, koalas are fussy, feeding on a very limited number of eucalypts, so they need to live in forests or woodlands containing their preferred trees,” she says.

“Urbanisation and habitat removal have precipitated koala population collapses in some areas because there simply isn’t enough habitat remaining for viable populations. In urban areas habitat also becomes fragmented, forcing koalas to move between patches, causing many animals to perish in road accidents or become the victims of dog attacks. 

“In south-eastern Australia some local koala populations in isolated habitat patches can grow rapidly and literally eat themselves out of house and home, eventually killing their food source, although this most commonly occurs in populations where mortality is quite low,” Dr Handasyde says.

“Australia-wide, habitat loss and fragmentation are the greatest threats to wild koala populations.”

And even though we humans may find koalas fascinating and adorable, the feeling is not necessarily reciprocated. 

Dr Jean–Loup Rault from the University’s Animal Welfare Science Centre says research conducted at Phillip Island Nature Parks’ Koala Conservation Centre showed too much interaction with the public could disturb koalas’ normal daily activities.

“Our study tested the effect of visitor numbers, visitor noise, and visitor proximity on koalas and showed that up-close and noisy encounters with human visitors resulted in ‘increased vigilance’. Such disturbance could cause stress, which would be energy-costly and potentially problematic because koalas survive on an extremely low energy diet, even minimising energy expenditure by sleeping 20 hours a day. 

“Some wildlife parks offer close encounters or even hands-on experiences with koalas, but only now are we beginning to understand the impact of these visitor encounters on koalas’ behaviour and welfare.

“The koalas we see being handled by visiting members of the royal family, for instance, seem calm and cute but these animals have trained handlers. 

“The general public should remember koalas are wild animals, with sharp teeth and claws, and can inflict serious injuries,” Dr Rault says.

Dr Natalie Briscoe from the University’s School of Botany and Department of Zoology is also researching koala behaviour, and in particular their response to extreme temperature conditions.

“Drought, bushfires and extreme temperatures can also put stress on koala populations,” Dr Briscoe says.

“Our research looked at how koalas cope with extreme heat. While panting and licking their fur during hot weather helps koalas cool down, this can also lead to dehydration. Our thermal imaging data revealed koalas cope with extreme heat by hugging cool tree trunks. We found the trunks of some tree species can be over five degrees celcius cooler than the air. Resting against cool tree trunks can save about half the water a koala would need to keep cool on a hot day, which significantly reduces the amount of heat stress they experience. Cool tree trunks are likely to be an important microhabitat for animals under current and future climate scenarios,” she says.

 

www.zoology.unimelb.edu.au/