A new analysis of the social networks of female wild red deer on the Isle of Rum in Scotland shows that aging deer tend to adopt a life of solitude as they grow older.
A multidisciplinary team led by researchers from the universities of Oxford and Edinburgh has found that wild red deer become less social with age.
Lead author Dr Greg Albery, from Oxford University’s Department of Biology, said: ‘We found that deer social networks shrink as they age and begin to associate less to others. This “social aging” appears to be driven by older people choosing to live in more isolated locations and engaging with fewer other deer in these more sparse areas.
Building a general understanding of how individuals change their social behavior as they age is useful for research on many different species, including humans. Such research sheds new light on the consequences of senescence for aging people, while potentially providing insight into how societal structure and function might change as the population ages.
The team applied new methods of social network analysis to a large 46-year-old dataset consisting of more than 200,000 census observations of more than 3,500 female deer over their lifetimes.
As female deer age, they begin to interact with fewer other individuals within their home range. They also shift their locations to less populated areas of their habitat.
In addition to becoming less central in the social network, older females were generally found with smaller home ranges, farther from the center of the population, in areas of lower density, and with lower quality pasture.
“This new evidence of social aging in the wild shows the value of long-term data sets. By tracking many individuals simultaneously throughout their lives, we can understand how and why their social associations with each other change over time,” said Josh Firth, Department of Biology, University of Oxford and lead author of the study.
While previous work has shown that older wild animals of other species may be less sociable than younger animals, it was previously unclear whether this was due to demographic changes or more sociable individuals dying earlier. . However, using this long-term dataset, the new research shows that social aging occurs at the individual level, where individuals actively become less social throughout their lives.
The research also highlights that more work is now needed to understand exactly why aging deer are becoming less social. The authors suggest that this social aging may be due to a combination of many factors, such as moving to areas where older individuals can more easily forage or changing their behavior to become more socially selective in their relationships with people. other deer.
Dr Albery added: “Combining social media with spatial location data has allowed us to unravel the potential causes of these age-related declines in social behavior and show how individuals change their behavior across the lifespan. their life.”
Researchers now hope that bringing these scientific approaches to other long-term wild animal datasets will help generate a broader view of the fundamental rules that may govern aging and social behavior in natural populations.