Giraffes with Large Groups of “Friends” Live Longer

Adult female giraffes that live in large groups survive longer than animals that are more socially isolated, new research finds. Even though specific relationships might change, having several “friends” can help their life span.

Giraffe groups are interesting because they have what is known as “fission-fusion” dynamics, lead researcher Monica Bond of the Department of Evolutionary Biology and Environmental Studies of the University of Zurich, tells Treehugger. That means their groups will merge and split often throughout the day and memberships in groups also changes frequently. Similar systems also exist in many other hoofed animals, as well as whales, dolphins, and some primates.

“But within that fission-fusion system of daily merging and splitting, female giraffes maintain specific relationships (friendships) that are stable over years,” Bond says. “When we say relationships, we mean that they are seen grouping together frequently over time, so we think they regularly ‘check in’ and ‘hang out’ with each other, moving around and eating together and watching over their calves together.”

Bond and her team have been studying giraffes in the Tarangire region of Tanzania since 2012 with the goal, she says, of learning what helps and hurts them in order to conserve them for the future.

They learned to recognize giraffes by their unique spot patterns and observed them over time. Each time they saw a giraffe, they recorded which females were in the same group together. They used friendship patterns to determine each female giraffe’s level of sociability.

They also looked at other factors in the environment that are strongly correlated with the animals’ chances of surviving including the types of vegetation that surrounded them and their distance from human settlements.

They analyzed how all these factors influenced how long the animals lived and which were most important.

“We found that females that tended to be in groups with more other familiar females—which is called gregariousness—had better survival,” Bond says. “Moreover, their gregariousness was more important than vegetation and nearness to human settlements. So this is why we concluded that friends matter to giraffes.”

The results of their research were published in the journal the Proceedings of the Royal Society B.

The Benefits of Friendship

Giraffe friendships appear to offer many benefits. Beyond poaching, the primary causes of mortality for adult female giraffes are usually disease, stress, or malnutrition. Being part of a group can help prevent these issues.

“We speculated that being less solitary, for example tending to group with at least three other females, benefits adult female giraffes by improving foraging efficiency, helping manage interspecific competition, protecting their calves from predators, and reducing disease risk and psychosocial stress,” Bond says. 

“They can cooperate in caring for their calves, avoiding harassment from males, and sharing information about food sources. All of this reduces their stress and improves their health.”

The results show that giraffes have similar social habits as humans and other primates, where having greater social connections offers more opportunities.

“Humans and non-human primates like chimpanzees and gorillas also benefit from sociability, not by living in small, closed groups with just a few friends, but by being more socially connected within our larger community of associates,” Bond says.

“Having more social ties directly improves our health and longevity. This has been shown often in humans and primates but this is the first time we’ve shown this to also be true in giraffes. Understanding the importance of giraffe social relationships to their survival and fitness helps us to develop better conservation strategies that avoid disrupting those relationships, so giraffes and people can co-exist together.”