New evidence suggests kangaroos are better friends than we thought

By Liam Taylor 28 September 2023

A PHD student from the University of New South Wales has found Australia’s most iconic marsupials make long term friendships and share complex social bonds.

Contrary to previous beliefs that Eastern grey kangaroos maintained only fairly simple social structures, the study by Nora Campbell, a PhD candidate from the School of Biological, Earth & Environmental Sciences (BEES), suggests the species may develop and retain long-term relationships.

Previous studies had already indicated that relationships developed between individuals in friendly groups span years and that mothers in particular enjoy being part of such friendly groups. But these latest findings would suggest eastern grey kangaroos have more similar social lives to humans than we imagined.

"We found that kangaroos had maintained friendships with the same individuals over consecutive years and this was really exciting because there hasn't been any evidence for long-term friendships in kangaroos before," Campbell told ABC News.

But while female kangaroos were looking for more complex friendships with those around them, males seemed were mainly interested in just one thing.

"The male's mating tactic is quite simple; they will just try to mate with as many females as possible," she said.

The research also revealed a departure from prior studies, indicating that mother kangaroos exhibit greater social tendencies compared to their non-parental counterparts. Nevertheless, these maternal kangaroos tend to favour smaller group settings over larger mob gatherings.

“Previous studies have shown that mothers tend to take their joeys and isolate from the rest of the kangaroos, whereas we found that our mothers had a much higher sociality than kangaroos who weren't mothers," Campbell told ABC News.

"We think what was happening is that they were still forming small groups when they became mothers, but they were just changing their groups more frequently and meeting with a higher number of kangaroos overall."

The study faced the usual challenges associated with long-term observation of animal behaviors. Kangaroos are particularly challenging to monitor due to their fission-fusion social structure, characterized by the formation and dissolution of small groups multiple times daily.

In this study, Campbell and her supervisor, Associate Professor Terry Ord, meticulously analyzed a collection of over 3,000 photographs capturing a single group of eastern grey kangaroos over a six-year period. Identification of individual kangaroos relied on the unique characteristics of their ear shapes.

This approach allowed the research team to uncover evidence of enduring relationships among the eastern grey population studied. Furthermore, by tracking the reproductive status of all females in the population, they observed that female kangaroos with joeys actively formed connections with other mothers.

The findings, recently published in the journal Animal Behaviour, offer fresh insights into the social dynamics of these well-known animals. The implications of this research extend to the management of kangaroo populations and the broader conservation efforts aimed at safeguarding various species.

Understanding the behaviours of sentient animals is essential for not only enhancing their protection but also for the preservation of the ecosystems they inhabit.

Planet Ark does not take responsibility for the accuracy of the original information and encourages readers to check the references before using this information for their own purposes.

Liam Taylor
Prior to joining Planet Ark Liam spent his time studying global environmental issues, travelling Southeast Asia on the cheap and working for a sustainable property management company in Bali, Indonesia. Joining the communications team at Planet Ark, he hopes to inspire positive environmental behaviour through effective and positive messaging.