Why Do Koalas Spend Their Days Hugging Trees?

Why do koalas turn into tree huggers during Australia’s hot summer months? A June 2014 study published in the journal Biology Letters found that koalas move to the lower parts of a tree and press their bodies close to the trunk in order to cool down. The temperature of the tree trunks, the University of Melbourne researchers found, was several degrees cooler than the air temperature on the hottest days of summer.

Researchers used a thermal camera to take pictures of how the koalas behaved on the hottest days. “You could see the koala sitting on the coolest part of the tree trunk with its bottom wedged right into the coolest spot,” explained university researcher Michael Kearney.

Don't call them bears:

• Koalas are not bears, so calling them "koala bears" is inaccurate.
• Koalas are marsupials, which means that their young are born immature and then develop further in the safety of a pouch.
• Koalas are mostly nocturnal -- they tend to be awake at night and asleep during the day, though this is not a hard and fast rule. Koalas often sleep up to 20 hours a day.

Frequently Asked Questions

Why do koalas hug trees?

Koalas embrace trees primarily to regulate their body temperature. According to research from the University of Melbourne, the trunks of trees can be up to 5°C cooler than the air on hot days, providing a natural cooling system. This behavior helps koalas conserve energy and maintain a comfortable body temperature in the varying Australian climate.

How much time do koalas spend in trees?

Koalas are arboreal marsupials, spending up to 20 hours a day in trees. They sleep most of this time, nestled in the forks or nooks of trees. The time spent in trees is crucial for their safety, feeding on eucalyptus leaves, and thermoregulation, as the ground poses more threats and offers less food and comfort.

Do koalas only hug eucalyptus trees?

While koalas primarily feed on eucalyptus leaves, they do not exclusively hug these trees. Koalas have been observed hugging different types of trees, but they show a preference for trees with smoother bark and those that provide substantial foliage cover, which are often but not exclusively eucalyptus trees, for their dietary and thermoregulatory needs.

Is tree-hugging behavior unique to koalas?

Tree-hugging is not unique to koalas; however, their particular use of this behavior for thermoregulation is quite specialized. Other animals also climb or rest in trees for various reasons, such as seeking refuge from predators, foraging for food, or resting. But koalas are especially known for their distinctive tree-hugging posture.

What other benefits do koalas get from trees?

Beyond thermoregulation and safety, trees provide koalas with their primary food source: eucalyptus leaves. These leaves are not only their diet but also their main source of hydration, as koalas rarely drink water. The trees also offer a platform for social interactions and a place for koalas to rear their young.

How does deforestation affect koalas?

Deforestation poses a significant threat to koalas, leading to habitat loss, fragmentation, and a decrease in food supply. It also increases the risk of overheating and predation as koalas are forced to descend to the ground more frequently to move between trees, making them vulnerable. Conservation efforts are critical to protect their natural habitat and ensure their survival.