Young Male Koalas Were Caught Being Unexpectedly Affectionate Towards Each Other, Which Is Strange Since They’re So Solitary

Koala climbing up a tree.
AUFORT Jérome - stock.adobe.com - illustrative purposes only

In a forest west of Melbourne, Australia, a scientist tracking koalas unexpectedly recorded young male koalas engaging in affectionate behaviors with each other, such as grooming and play. It was a shocking discovery since adult koalas are known to be solitary.

A new study presents the most comprehensive account of these behaviors so far and gives rare insight into how koala social interactions may shift when they are confined in smaller spaces.

Most animals exhibit social behavior of some sort, whether it’s mating, vocalizing to communicate, or protecting their territory.

But some highly social animals that live in groups, like dolphins, primates, and wolves, will show friendly and peaceful acts between individuals, such as grooming and playing with each other.

These are referred to as affiliative behaviors, which play a crucial role in social bonds and help maintain complex social hierarchies.

However, adult koalas are normally solitary. They are spread out across a wide area and do not encounter each other often. They interact across long distances by vocalizing and leaving their scent behind.

When male koalas do physically interact, it is usually very violent. Male koalas have been seen with scratches, bloody wounds, and missing chunks of fur and claws.

Darcy Watchorn, a researcher at Deakin University, spent three weeks studying a koala population in Cape Otway in southern Victoria. Between the hours of 9 p.m. and 2 a.m., he used a red-light spotlight to observe the males.

After two weeks, he noticed three males grooming each other, vocalizing in soft, high-pitched calls, and sniffing each other’s privates.

Koala climbing up a tree.
AUFORT Jérome – stock.adobe.com – illustrative purposes only

Sign up for Chip Chick’s newsletter and get stories like this delivered to your inbox.

They also appeared to be playing by gently biting each other on the arm and ear. The interactions went on for quite some time.

The scientist watched the koalas for two hours before falling asleep. The next day, they were still interacting. This kind of social interaction among wild koalas had only been documented once before in a densely populated koala community on French Island off Victoria more than 30 years ago.

In both the earlier observation and the latest interaction, the koalas were young adult males between the ages of three and five.

At this stage in life, their hormonal activity is higher than ever, which can lead to an increase in social behaviors like play and boldness.

Yet, affectionate behaviors are rarely seen in koalas of this age group, so they are most likely not just the result of teenage hormones.

Instead, the behaviors may be due to large koala populations. Generally, fewer than two koalas are found per every two acres. But at Cape Otway, there were 15 koalas for every two acres.

This means the home ranges of koalas can overlap, and their interactions will be more frequent. In addition, competition for food, mates, and space can be fierce.

So, young males may use affectionate behaviors like grooming and playing to manage stress and reduce conflict.

Furthermore, this population had low genetic diversity, so they are more closely related and may have more tolerance for each other.

High-density koala populations can pose conservation problems. Too many koalas feeding in the same area can lead to the death of preferred trees and habitat loss.

Some koalas could even starve. It’s impossible to relocate koalas because of climate differences and the unique gut bacteria needed for local food trees.

Fertility control could be effective, but it would take years of effort and funding to achieve. There is a bright side to all this, though. At least koalas are acting a lot nicer to each other now!

The study was published in Australian Mammology.

Emily  Chan is a writer who covers lifestyle and news content. She graduated from Michigan State University with a ... More about Emily Chan

More About: