A 20-year study of mountain gorillas uncovers the nuanced benefits and drawbacks of social bonds, offering insights into the complexities of friendship among primates.
Key Points at a Glance
- Long-term research on 164 mountain gorillas examines the impact of social relationships on health and reproduction.
- Findings indicate that the advantages and disadvantages of social bonds vary by group size and gender.
- Friendly females in small groups experience fewer illnesses but have lower birth rates; those in large groups face more illnesses but higher birth rates.
- Males with strong social ties are less likely to be injured in conflicts but may experience increased illness, possibly due to stress.
- The study suggests that there is no one-size-fits-all approach to sociality, reflecting the complexity of social behaviors in primates.
In a comprehensive study spanning two decades, researchers have delved into the social dynamics of 164 mountain gorillas in Rwanda’s Volcanoes National Park. The collaborative effort by the Dian Fossey Gorilla Fund and the universities of Exeter and Zurich aimed to understand how social relationships influence health and reproductive success among these primates.
The study revealed that the effects of social bonds are multifaceted and depend on various factors, including group size and the individual’s gender. For instance, female gorillas with strong social connections in smaller groups tended to have fewer illnesses but also produced fewer offspring. Conversely, those in larger groups faced higher rates of illness but had increased birth rates.
Male gorillas presented a different pattern. Those with strong social bonds were less likely to sustain injuries during conflicts, suggesting that social ties may offer protection. However, these males also experienced higher rates of illness, which researchers speculate could be due to the stress associated with maintaining social relationships and responsibilities like group defense.
Dr. Robin Morrison, the lead author and a senior researcher at the University of Zurich, emphasized the complexity of social relationships: “Having a lot of strong social relationships is often really good – but sometimes it isn’t.” She noted that the benefits and drawbacks of social bonds are not uniform and can vary significantly based on individual circumstances.
The research also highlighted the diverse social strategies among gorillas. Some individuals, like the silverback Titus, maintained long-term dominance through gentle and calm leadership, fostering strong bonds with group members. Others, such as the female gorilla Maggie, exhibited assertive behaviors and took on protective roles typically associated with males, even leading her group after the dominant male’s unexpected death.
Dr. Sam Ellis from the University of Exeter pointed out that these findings challenge the notion that more social connections are always better. “Our study shows this isn’t a straightforward case of more and stronger social ties always being better,” he said. “In some situations, social traits that we’ve previously thought of as maladaptive can have important benefits.”
The study underscores the importance of long-term research in understanding the evolution of social behaviors. By observing gorillas over extended periods, scientists can gain insights into the complex interplay between sociality, health, and reproductive success, which may also shed light on human social evolution.
Source: University of Exeter
