Female Baboons Find a Secret to Longevity: Close Girlfriends

http://blogs.discovermagazine.com/80beats/2010/07/02/female-baboons-find-a-secret-to-longevity-close-girlfriends/

Female Baboons Find a Secret to Longevity: Close Girlfriends

Posted: 02 Jul 2010 02:19 PM PDT
Apparently, in the animal kingdom, it's better to be a girl. We have seen that women macaques are superior conversationalists. We learned that lady humpbacks enjoy long-lasting friendships. Now research published in Current Biology shows that baboon ladies with good friends around them may live longer.

At Botswana's Moremi Game Reserve, Joan Silk of the University of California, Los Angeles and her team spied on 44 female chacma baboons over the course of six years. Among other things, Silk looked at which girls had the most visitors and how often the women picked junk out of each other's hair. In other words, true friendship. She also tracked each baboon's circle of friends, seeing how each lady's top three buddies changed over time.

Silk saw a correlation between sociability and longevity. She divided the baboons into three groups, and found that the least friendly lived 7 to 18 years, while the friendliest group lived from 10 years on (they were still kicking when the study ended). They also found that those baboons who formed stable, enduring bonds were more likely to have long lives than those with flightier friendship habits. It's tempting to look for parallels between baboons and humans, and indeed, the researchers engage in a little speculation.

Such findings in a nonhuman primate, the authors write, "suggest that the human motivation to form close and enduring bonds has a long evolutionary history." ... They note that previous research in humans has shown that socially isolated people suffer more from high blood pressure and sleep disorders and have longer wound-healing times.

But back in the animal world, it's still not clear how these stable friendships could make baboons live longer. It's possible, they say, that more friendly grooming could mean fewer parasites, or more social interactions could mean more eyes to watch for predators.

"It all depends on what causes the death of female baboons, which is hard to determine because there's seldom a single cause," comments New York University anthropologist Clifford Jolly. In this baboon species, males miss out on friendship and its possible benefits. It seems that chacma males never groom each other, and only
groom women before sex.