Australian summers are known for their heat, with temperatures in koala territory - Queensland, New South Wales, Victoria and South Australia - frequently exceeding 30°C. The people living in these regions combat the heat with air conditioning and swimming pools, but no such relief exists up in the trees where koalas live. So how do these furry critters cool down in the summer? And conversely, how do they keep warm in winter? Let’s take a look.

Surviving summer

In Rachel Bright and Jim Field’s koala story book, The Koala Who Could, Kevin the koala prefers hugging his tree to venturing to the ground to play with his friends. But did you know that there’s much more to tree-hugging than scientists previously thought?

In 2019, scientists at the University of Sydney observed a colony of koalas during the hottest time of the year. They found that tree-hugging helps koalas to regulate their body temperature, meaning they can keep cool even on the toastiest of days. The koalas cuddle up to tree trunks, which are cooler than the air temperature, and this enables them to lose excess heat. 

Although koalas eat eucalyptus, they tend to hang out in acacia trees when the weather is at its hottest, since the trunks can be as much as 8.9°C cooler than the surrounding air temperature. The team found that koalas can also predict days of extreme heat - when temperatures reach up to 40°C - from the temperatures overnight and in the early morning. They lowered their body heat accordingly, enabling them to cope as the heat rose during the day. This ability helps them to retain an estimated 18% of water, reducing the need for them to go down to the ground to find it - which can be risky for koalas.  

Other forms of heat reduction for koalas include panting and licking their fur, which cools them down when the moisture evaporates. 

Winter warmth

Koalas have adapted brilliantly to Australian summers, but what about when things turn colder? Koalas’ thick, woolly fur acts as a natural insulator, meaning it’s great at keeping heat in and can protect them from cooler temperatures and rain. Koalas in the southern parts of Australia, where the weather is colder, have thicker, darker fur than those in the north. This is a clever adaptation to ensure they stay warmer.  

Koalas also have a particularly thick, dark patch of fur that runs along their backs. This is waterproof and provides a good shield against the weather when the creatures curl into a ball to stay warm. 

Meet Kevin the koala

If you love a koala, reading a book about them will give you all sorts of interesting facts to share with family and friends. And why not head to your local theatre to see The Koala Who Could, which is currently touring the UK? This charming koala show brings Rachel Bright and Jim Field’s story to life with songs, dancing and puppetry, making for a fun day out for the whole family. Book your tickets today!