Koalas use a range of sounds to communicate with one another over relatively large distances.

There is a deep grunting bellow which the male uses to signify its social and physical position. Males save fighting energy by bellowing their dominance and they also bellow to allow other animals to accurately locate the position of the caller.

Females do not bellow as often as males, but their calls too are used to express aggression as well as being part of sexual behaviour, often giving the impression of fighting.

Mothers and babies make soft clicking, squeaking sounds and gentle humming or murmuring sounds to one another, as well as gentle grunts to signal displeasure or annoyance.

All koalas share one common call which is elicited by fear. It is a sickening cry like a baby screaming and is made by animals under stress. It is often accompanied by shaking.

Koalas also communicate by marking their trees with their scent.

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