Koalas are "tree huggers" for a cool reason

10 June 2014

University of Melbourne researchers observed the behaviour of 30 koalas during hot weather at French Island, to the city’s east. They found that while panting and licking their fur helps koalas cool down, this can also lead to dehydration.

University of Melbourne science
Koalas “hug” cool tree trunks for survival

Lead researcher Natalie Briscoe, from the Melbourne School of Botany, said koalas were observed hugging cool tree trunks.
“We found trunks of some tree species can be over 5°C cooler than the air during hot weather,” she said. “Access to these trees can save about half the water a koala would need to keep cool on a hot day. This significantly reduces the amount of heat stress for koalas.”
Researchers used a portable weather station on a long pole to measure what the koalas were experiencing in the places they chose to sit compared to the places available to them.
Co-author Dr Michael Kearney said “the findings were important as climate change is bringing about more extreme weather.”
“When we took the heat imagery it dramatically confirmed our idea that ‘tree hugging’ was an important cooling behaviour in extreme heat. Cool tree trunks are likely to be an important microhabitat during hot weather for other tree-dwelling species including primates, leopards, birds and invertebrates.
“The availability of cooler trees should be considered when assessing habitat suitability under current and future climate scenarios.”
Study collaborator Professor Andrew Krockenberger, from James Cook University, said “heat wave events can hit koala populations hard.”
“About a quarter of the koalas in one population died during a heat-wave of 2009, so understanding the types of factors that can make some populations more resilient is important.”

University of Melbourne School of Botany

The Melbourne School of Botany is renowned internationally as a leading department for research and training. The school offers an exciting and stimulating research environment to study plants and plant processes. Programs cover the broad spectrum of basic, strategic and applied research. Active collaborations are with universities and Research Institutes within Australia and overseas, the Royal Botanic Gardens Melbourne, State and Federal government agencies, and industry.
As a leading research department, the school’s focus is on three major areas of importance to Australia:

  • Plant Cell Biology and Biotechnology
  • Bioresources – Plant Biodiversity
  • Sustainability of the Environment

Sustainability of the Environment – Ecological research allows us to understand how ecosystems work, the risks associated with human impact, and how to fix environmental problems for a sustainable future.

  • Plant Ecophysiology
  • Plant Ecology
  • Environmental Risk Assessment
  • Conservation Biology


Find out more about studying science at the Melbourne School of Botany. Contact OzTREKK Admissions Officer Rachel Brady for more information about environmental sciences degrees in Australia! Email Rachel at rachel@oztrekk.com or call toll free in Canada at 1-866-698-7355.