Tuesday, August 19, 2008

Chimp Politics

It is 8:30 AM on the second full day of the conference and I have already lost my name-tag. Things are going well. There are five people (with at least four PhDs among them) trying to deduce why the projector for the Keynote Address isn't working.
There are about 300 conference participants here, half of the usual ABS meeting. The reason, other than the scheduling conflict, seems to be that they are having it at the Snowbird Ski and Summer Resort. The problems with this are two. First, they had their meeting here in 2006, and a significant part of why many people decide to go to conferences is to have an excuse to visit a new and exciting place. The second problem is that the Resort is an industrial scale conspicuous consumption machine, meaning that it is overbuilt, overdone and overpriced. I have to admit that it is in a beautiful place, and I will be posting pictures of a moose and some marmots some time soon.

Looks like the projector is working, John Mitani is a well known expert on primate behavior, and has performed fieldwork on all five species of non-human apes. He is giving the Keynote Address, and I will try to convey in non-technical terms my understanding of his understanding of what he says (Or at least that part of it based on previously published work. I don't actually know, but I suspect it would be very rude to distribute the parts of his talk that he had not yet published.)

He has been studying the social behavior of the chimps of southwest Uganda for the last 14 years. Male chimps are more social than the females, form more lasting bonds, move more broadly over a group territory and more often cooperate in coalitions. Male coalitions seem to serve the function of supporting their members in conflicts with other males. The male with the most coalition support rises to the top of the social status, even if he is not the smartest, strongest etc. (A slide of Bush and Cheney somehow appeared in his talk.) The alpha male gets most of the mating opportunities, but in times of coalitional uncertainty, will cede those opportunities to other males whose coalitional support they need.

Chimps are also group hunters, especially of young monkeys. Most of the hunters are adult males. A large group of male chimps will surround a troop of monkeys, and are extremely frequently successful, even if the amount of food per hunter is very small. But group hunters are not necessarily cooperative hunters. If 50 guys all go for the same prey, they may successfully grab it, but that doesn't necessarily mean they are intentionally helping each other. Each individual may be trying to be the one who grabs the meat.

But the chimp who catches the monkey is likely to share it with others. Why? Males are the primary hunters, and hunt mostly when there are a bunch of other males around. It is suggested they may go hunting for male-bonding purposes. The meat seems to be used as a political tool. Males use meat to buy coalition support from other males.

Male coalitions will also make territorial patrols and raids into the territory of neighboring groups. They defend their own territories and grab more land, not infrequently resulting in serious injury or occasionally death. The larger the group patrolling together, the less the risk from any rival group encountered. Dr. Mitani's study group has killed 18 rival males in 10 years, because they are the largest group around. He wants to show us a video of chimps attacking each other, but is having technical difficulties. Now we see another video of a gang of male chimps beating another to death. The room is very still.

Female chimps disperse to other groups, males do not. So males are potentially living in groups of close relatives. And it turns out that males do preferentially help their maternally related brothers. It is easy to know if you have the same mother as another chimp. It is much harder in a non-monogamous species to know if you have the same father, and males don't preferentially help paternally related brothers.

He is finished telling us about the chimps in particular, and is going on to discuss the differences between those who study the behavior of primates and the broader animal behavior community. He says that primatologists can be overly focused on the primates, but that the broader behavioral biological community can be overly resistant to viewing the primates as relevant to their own work. This is apparently one shot in an arguement I was not aware of, and it seems odd to raise it here. One of the biologists sitting near me mutters that he regularly references primate papers, while he never sees primatologists reference the frog literature.

The address is over, time for bagels, juice and schmoozing. Then I'll try to take pictures of the marmot that hangs around on the hotel lawn, and find my name tag.

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