It's hard out here for a chimp

Two days after I met Alex he got into a fight with Unyoro, the alpha male for the Chimp B group. The keepers found the little guy beaten up with one finger hanging off that they decided to remove. The researchers are puzzled because Alex is seldom as annoying as his sisters and not likely to challenge an older chimp at his age (5 yrs old). I saw him yesterday climbing one handed and staying out of the way of all the adults. He still carried his blanket with his foot.

Fights break out all the time among chimps for reasons not always evident to the novice observer. Juvenile males start to harrass adult females in order to assert their dominance. The alpha male eventually gets challenged by the young turks in the group. In the A group, Frodo periodically has attempted to assert his primacy only to be smacked down by Robert, the alpha, and Patrick, the third adult male who supports Robert. Alliances are more important than size, as described by Frans de Waal in Chimpanzee Politics.

The alpha male occasionally beats up one of the adult females, but females harass each other too. Swela joined the A group last year and has had a tough time integrating. The other females would beat her and chase her away. Eventually, she ingratiated herself to the adult males who now protect her from the other ladies. Swela does have the strange habit of making male-like sexual solicitations toward some of the females - she stamps her feet at them. But this has not gone any further.

Aggression usually takes the form of chasing, screaming, hitting with sticks or fists while the rest of the group hoots like crazy - basically, like the World Cup matches. But it seldom leads to the kind of damage that Alex suffered. When real problems between chimps develops, the care-takers can see it building over a few days and separate the troublemakers.

The cell phone incident

Several researchers described an event that occurred a few weeks ago in the large chimp group (Group A). One of the researchers accidentally dropped a cell phone into the outdoor arena. The phone immediately became an object of interest being monopolized by one animal and then taken away by a more dominant chimp. Eventually, the phone ended up in the possession of the alpha male, Robert. As Daniel Haun (a post doc) noted, this was not a coincidence. Unfortunately the episode was not captured on video.

For me, this incident raises questions about the origin of value - how does a non-food object become valued in a community? I think this is the central question in the origin of property. Attachments like Alex's security blanket are ends in themselves; it gives him comfort and arguably can be viewed as an extension of self (or so Lita Furby, 1980 postulates). Burlap sacks are also available to all the chimps and so probably nothing special. The cell phone on the other hand was truly novel, a rare find - so interesting that chimps fought over it and eventually destroyed it. But why would it be valuable? In a zoo setting, the simplest explanation is that it can be exchanged for food. According to the researchers here, apes in zoos quickly figure out that if they get a hold of a zoo keeper's pen or walkie-talkie, they can demand food for its return.

Anything related to food is learned quickly and the exchange idea has cool implications for research. One student here, Katrin, used an exchange task as part of her experimental design (investigating gratitude and guilt). She told me that the exchange part required almost no training - all of the animals (orangs) figured out how to trade sticks for food quickly. Contrast this with the capuchins at Yale who took a while to learn trading - apparently they were introduced to the process as infants. There could be some very interesting comparative work here using some fungible currency.

There is a temptation to compare the cell phone incident to the conch in the Lord of the Flies. I resist this because the dominance hierarchy for chimps is very strict and based on both physical strength and alliances. Thus the alpha male will always get the conch, but possession of the conch cannot establish status.

The general interest in the cell phone, however, warrants some exploration. Perhaps, some objects are simply interesting by virtue of their novelty. If this is the case, the possessor would not be quite so willing to relinquish the object even for food. Or some objects would command a premium.

Alex and his security blanket

A few days ago I sat in on a training session with one of the nursery raised chimps called Alex. He is five years old, a juvenile, and very energetic. The nursery chimps (Alex plus two females) were raised by humans for several years at the zoo. One researcher, Suzanne, spent 8 hours a day with these guys while others took the night shifts. As a result, there are strong attachments both ways between the researchers and these animals. In the past year or two, the zoo set up a separate chimp group in order to integrate the nursery chimps into normal chimp life here. The three A's (Alex, Alexandra and Annet) now belong to a group with 4 other chimps who were mother raised in the Chimp A group. This is working out well, but the 3 A's still love human contact. They even turn their backs to certain researchers at the bars of the indoor cages - a chimp behavior meaning "groom me, please." [Note: the development of the 3 chimps is documented in an SRCD monograph that came out in 2005, Tomasello and ???].

On this particular day, Alex was being trained to imitate a human. He had already learned about 7 gestures such as tap your head, smack the floor, pat your tummy, etc. Several more were proving very difficult such as raise your arm and shake your wrist. Alex would do a few imitations getting food each time, then get up and walk around or climb the cage, then come back for more. I noticed that he carried a piece of burlap sack with him and asked about it. According to Josep Call, he has kept that security blanket with him from his nursery days. Apparently, this kind of attachment to an object, common in human children, only occurs with nursery raised chimps. Josep believes the absence of a mother underlies the phenomenon.

Alex became frustrated with the imitation game after about 15 minutes. The researcher decided to stop the training and we got to play with him a bit. Alex remained in his cage area; he is small but very strong and I could tell when he casually banged on the plexi glass separator - a playful tap would knock you off of your feet. So we ran from side to side of the cage as I frequently do with my dog. And we tugged at his burlap blanket. I even got to feed him through the grates, directly into his mouth. Generally, you would never do this with a chimp - you place food in their hands. But Alex is a special case.

Orangutan sex

On my first day observing the primates, I wandered over to the orangutan area just in time for a special event. The alpha male, Bimbo, was actually interacting. Bimbo looks like a 400 pound muppet and generally he just sits around eating lazily. But he is the master of this little arena. Orang males do not tolerate other males, so in this area it is Bimbo and about 5 females - lucky guy.

And it is good to be king. The ladies willingly have sex with him whenever he wants. This day I watched Bimbo groom one of the females - her back was to him and she was holding an infant. Bimbo pawed at the infants hands a bit and patted the female. The female then got up and started to walk away slowly down off the rocks to a flat grassy area. She kept looking back, not running away - this may have been solicitous. Bimbo followed her, not chasing, but staying close. She laid down on her back, pushed the infant away to another female sitting next to her, and spread her legs. Bimbo moved into position. He was sitting up, legs bent with feet on either side of her, resting back on his hands and thrusting with his hips. He changed positions frequently, shifting to the left and then right, then center, pausing every minute or so for about 10 seconds and then continuing. The female just laid there without protest. At one point she covered her eyes with one hand and kept it there for about 10 minutes. The whole episode lasted about 15 minutes and ended without evidence of a climatic event. Bimbo just got up and walked away as did the female, and went back to their normal routine.

(Throughout the love-making, zoo visitors would walk by and take a moment to realize what was happening. Then laugh awkwardly, particularly parents with their children.)

Now, not all orangutan love is so peaceful. There are two types of males - the large alphas like Bimbo and smaller dudes that are adults who remain the size of juveniles. The ladies don't like the small guys, so they take what they can't get. Basically, they rape the women when the alpha males isn't around. Apparently, this can be very violent. No wonder the zoo does not have any of the small males in residence.

Life in Pongoland

I arrived in Leipzig, Germany on June 20, 2006 to spend 6 weeks at the Max Planck Insititute for Evolutionary Anthropology. The facility here is incredible. The Institute is in a beautiful modern building; there is an outdoor courtyard with a little pond with ducks and turtles swimming around and tables all around. I have office space here and access to all of the resources including a library.

The zoo is across town, about 15 min by bike. The main MPI facility is part of Pongoland, a central building housing 4 ape species - chimpanzees, bonobos, orangutans and gorillas. There are multiple testing rooms for each species used between 8:30 to 12:30 am. After that, the animals go outside to the regular zoo observation areas. The roof of the central building has viewing areas for researchers only. Here, you can sit in the sun with binoculars or video cameras and just watch. I did this for several hours my first day there - it is really amazing to watch these animals at such proximity. And to be able to walk to another corner and see a different species of primate! There are few places in the world where you can do this. Species comparisons arise as a matter of daily life here. And the collective knowledge of the researchers amazes me.