Baboons make love, not war

There's a great article in a recent New York Times (April 13, 2004) about a troop of baboons who have learned to live peacefully for over 20 years, but only after the most aggressive male baboons were killed. I've excerpted the most interesting bits below.

New York Times: Among a troop of savanna baboons in Kenya, a terrible outbreak of tuberculosis 20 years ago selectively killed off the biggest, nastiest and most despotic males, setting the stage for a social and behavioral transformation unlike any seen in this notoriously truculent primate.

In a study appearing today in the journal PloS Biology, researchers describe the drastic temperamental and tonal shift that occurred in a troop of 62 baboons when its most belligerent members vanished from the scene. The victims were all dominant adult males that had been strong and snarly enough to fight with a neighboring baboon troop over the spoils at a tourist lodge garbage dump, and were exposed there to meat tainted with bovine tuberculosis, which soon killed them. Left behind in the troop, designated the Forest Troop, were the 50 percent of males that had been too subordinate to try dump brawling, as well as all the females and their young. With that change in demographics came a cultural swing toward pacifism, a relaxing of the usually parlous baboon hierarchy, and a willingness to use affection and mutual grooming rather than threats, swipes and bites to foster a patriotic spirit.

Remarkably, the Forest Troop has maintained its genial style over two decades, even though the male survivors of the epidemic have since died or disappeared and been replaced by males from the outside. (As is the case for most primates, baboon females spend their lives in their natal home, while the males leave at puberty to seek their fortunes elsewhere.) The persistence of communal comity suggests that the resident baboons must somehow be instructing the immigrants in the unusual customs of the tribe.

"We don't yet understand the mechanism of transmittal," said Dr. Robert M. Sapolsky, a professor of biology and neurology at Stanford, "but the jerky new guys are obviously learning, `We don't do things like that around here.' " Dr. Sapolsky wrote the report with his colleague and wife, Dr. Lisa J. Share.

Dr. de Waal, who wrote an essay to accompany the new baboon study, said in a telephone interview, "The good news for humans is that it looks like peaceful conditions, once established, can be maintained," he said. "And if baboons can do it," he said, "why not us? The bad news is that you might have to first knock out all the most aggressive males to get there."

Dr. Sapolsky has no idea how long the good times will last. "I confess I'm rooting for the troop to stay like this forever, but I worry about how vulnerable they may be," he said. "All it would take is two or three jerky adolescent males entering at the same time to tilt the balance and destroy the culture."

Posted by matt at April 22, 2004 12:42 PM