Gorillas are known to be non-territorial mammals but sometimes could show territorial behavior towards other groups. A new study reveals that they can be good neighbors, too. Mountain gorillas will gladly welcome long lost friends and greet other groups of great apes as long as they stay out of the core territory.
Researchers at the University of Exeter tracked the movements of mountain gorillas in Rwanda for 16 years. They found that the gorillas welcome familiar groups even after not seeing them for decades as long as they stayed on the outskirts of their territory. But they become aggressive if another group strayed too far into their territory.
For humans, having friends could result in cooperation and shared access to space and resources. This new study suggests that gorillas could benefit from maintaining friendships outside of their group, MailOnline reported.
Gorillas Display Territorial Behavior
Gorillas act aggressively when strange or other groups come into their core territory regardless of whether these intruders are familiar to them or not. However, they tend to be more tolerant of other groups that were previously united to them, and aggression only applies to less familiar groups.
According to Dr. Robin Morrison of the Fossey Fund and Exeter's Centre for Research in Animal Behaviour, different groups of gorillas rarely meet, and if they do, they usually are very cautious towards each other.
"They often beat their chests and show off their strength, but the interaction can then either become aggressive - with fighting and screaming - or 'affiliative'," Dr. Morisson said.
In affiliative interactions, the aggression between the two groups gradually passes, and they start to intermingle. Young gorillas would start playing with other youngsters from the other group and rest together, EurekAlert reported.
Gorillas as Friendly Neighbors
Humans live their lives by cooperating. They build friendships that extend beyond their primary group. One theory of evolution suggests that humans benefit from wider friendships that allow them on shared spaces and resources, leading to a reduced risk of aggression.
In the study of Dr. Morrison and his colleagues, published in the journal Animal Ecology, they analyzed the movement of interaction between 17 Mountain gorilla groups in the Volcanoes National Park in Rwanda for 16 years.
They said that gorillas tend to be four times more likely to be friendly if they were familiar with another group even after not seeing them for decades. Gorillas are happy to share the periphery but not their core territory.
This pattern of behavior seems to mirror those of humans, said Dr. Morrison. Humans have the concept of space wherein a specific range can be tolerated, and spaces that remain private and exclusive.
Heightened aggression is only shown to those unfamiliar groups. According to the researchers, an in-depth understanding of this behavior could aid in the conservation efforts of the endangered apes.
"Understanding how groups interact and share their limited space is important for estimating future population dynamics and trends in this endangered species."
