Female giraffes live longer when they stick together

Socialization makes a big difference in the life expectancy of adult female giraffes, according to a new study from the University of Zurich. The experts have found that female giraffes who spend more time with other females have a higher chance of survival than those who are less sociable.

For over five years, a research team led by Monica Bond has been conducting the largest study to date of a giraffe population. The site of the investigation, which is in the Tarangire region of Tanzania, spans more than 1,000 square kilometers and includes multiple social communities with hundreds of adult female members.

The researchers determined that the benefits of socializing outweigh the effects of environmental factors or human presence on the survival of female giraffes.

While group formations change throughout the day, adult females were found to maintain many special friendships over the long term.

“Grouping with more females, called gregariousness, is correlated with better survival of female giraffes, even as group membership is frequently changing,” said Bond. “This aspect of giraffe sociability is even more important than attributes of their non-social environment such as vegetation and nearness to human settlements.”

Beyond the threats of poaching and wildlife trafficking, adult female giraffe mortality is primarily caused by disease, stress, and malnutrition. 

“Social relationships can improve foraging efficiency, and help manage intraspecific competition, predation, disease risk and psychosocial stress,” said study senior author Professor Barbara König. 

For example, female giraffes may team up with other females to obtain information about the best places to find food. Socializing in larger groups may also lower stress levels, reduce harassment from males, and provide help in caring for young.

The team analyzed the social behaviors of the wild giraffes using network algorithms. The analysis showed that giraffes are surprisingly similar to humans and other primates in their social habits.

“It seems to be beneficial for female giraffes to connect with a greater number of others and develop a sense of larger community, but without a strong sense of exclusive subgroup affiliation,” said Bond.

The study is published in the journal Proceedings of the Royal Society B.

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By Chrissy Sexton, Earth.com Staff Writer