Monday, February 18, 2008

Fongoli chimps on Today Show, featured in NOVA special 'Ape Genius'

Here is a link to the Today Show segment that previews the NOVA/National Geographic film that aired on Tuesday, February 18, entitled, "Ape Genius". Dr. Victoria Horner and I discuss the film...

You can watch the Ape Genius video, chapter by chapter if you follow this link:

The Fongoli chimps are featured specifically in Chapters 1 & 2, although you will recognize clips of them and the field site throughout the video.

Wednesday, February 13, 2008

Big day at the cave!

February 10, 2008.

Today was an exciting day with the chimps because the young female Tumbo was in estrus, so a large party was in attendance. In addition to 8 adult males, a number of other females, along with their offspring joined the group. This is typical when a female is in estrus - it is a very social event, no matter who you are!

It was almost comical to watch 8 adult males keep an eye on Tumbo's every move - and to change their own travel trajectories to match hers! Meanwhile, Tumbo nonchalantly continues on her way, stopping frequently to eat (as is typical for her - I swear she eats more than any chimp I know!), seemingly without a care in the world for these 8 guys following her around. She does pay them a bit of attention at times, if you get my drift, but I wanted to write today about something else the males were very interested in.

One thing that makes the Fongoli chimps unique, compared to chimpanzee communities that have been studied elsewhere, is that they use caves for resting, feeding and socializing during the hottest times of the year - when these caves are cooler than the surrounding environments. Some of thes caves are more like rock shelters. There are also what we call 'dirt caves', which have been carved out by animals, under the banks of streambeds in the area.

Today, the large party (of about 27 individuals) set off for one of these small, dirt caves, which was located along the Kerouani stream. All of the streams are dry by this time of year. Diouf seemed to lead the way, and throughout the afternoon, as various tussles between males ensued, Diouf always seemed to remain near the cave and would jump back in first chance he got after a minimal amount of participation in a fight or two.

The highest-ranking male in the party, Yopogon (see photo here, taken by Maja Gaspersic Cisse in Dec. 2007), who is actually 2nd-highest ranking male behind Foudouko (who we haven't seen in over a month) didn't seem to be able to bully anyone out of the cave so that he could go in. Dominance interactions over females in estrus are much more indicative of the male dominance hierarchy than are interactions by males over food or space.

In this case, the chimps were eating soil from this particular cave (we call it 'geophagy'). Chimps at all long-term study sites have been observed to exhibit this behavior. Gorillas are better known for the behavior, and other primates exhibit it extensively as well - colobus monkeys, for example. It appears to provide some minerals to the diet, but in colobus monkeys, similar behavior (charcoal eating) also seems to detoxify some of the plants they consume.

In addition to being very much interested in eating soil (which was really hard for me to imagine - the temperatures were well into the 90's, and as far as I know, this chimp party did not drink on this day. I can't imagine how they did it - it made my mouth dry to think about it!), the males were interested in being able to lounge in the cave as well. Being a small cave, only about 3 males could fit comfortably in it. This caused more of a ruckus than having access to Tumbo did (although, granted, she is not quite at that stage of her estrous period where she is most 'attractive' to males)!

Yopogon proceeded to display at length up, over and around the cave in an attempt to supplant one of the other - lower-ranking! - males from it. This just wasn't working. They ignored his attempts, often reassuring one another as he stamped by. Finally, he appeared to take his frustrations out on Bilbo, who was not actually in the cave at the time but who was one of the first males to go in and eat. Bilbo did not take kindly to Yopogon's threats - I couldn't actually see if he slapped him, but it sounded like he did. A chase ensued and, as it frequently does, ended up high in the trees.

With Bilbo screaming in rage initially, and Yopogon finally screaming in fear, the rest of the party let loose with VERY loud WRAAAAHH barks, which are given during such aggression. You might think of them as being something along the lines of, "Stop it! Cut it out! Things have gotten out of hand!". They REALLY got upset as Bilbo and Yopogon actually grappled high in the trees, about 15 meters (45 feet, I believe) off the ground. At this point, I was standing in the midst of the hollering group, trying to see exactly what was going on.

The next thing I knew, Yopogon had grabbed a limb that would not support his weight, in an effort to elude Bilbo. The limb tore from the tree, and Yopogon plummeted about 12 meters (about 35 feet) to the ground!!! You can imagine the uproar!

At this point, I was afraid that what had probably happened to Mamadou (see post below) would be what I would then see with Yopogon.

Fortunately, he doesn't seem to have been seriously hurt and, actually, the fight continued along the ground for some time - over a hill and out of my sight.

Yopogon finally made his way back to the cave. When I turned back to look there immediately after the fall, I saw that a few females had taken advantage of the situation and had run inside to grab some clay. Diouf, who also didn't stray far from the cave, swaggered a little and chased them back, and went back to dozing and eating there for another couple of hours. Yopogon groomed with various males, trying to make up for the hurt feelings, etc., that had come out of all the aggression. I finally saw that he got as close as being able to lie at the lip of the cave. A very exciting day for me but one that is fairly typical for chimps - especially when you have a community, like Fongoli, that is characterized by so many adult males. All's well that ends well, I suppose...

Friday, February 1, 2008

Baboons, baboons, baboons...Jan 31, 2008

You have to love baboons.

They make somewhat rowdy chimpanzees (that’s what some people think anyway) look absolutely tranquil by comparison. There is at least one troop of baboons that shares the home range of the Fongoli chimps. There are at least 100 individuals in this troop, and if they are like the baboons studied by Martin Sharman 25 or so years ago in Niokolo Koba National Park here in Senegal, they also exhibit a fission-fusion social structure. Unlike the “typical” chimp fission-fusion social structure, however, these monkeys come back together almost every night to a common sleeping site. (More about the apparently ‘atypical’ fission-fusion behavior of Fongoli chimps in another blog!).

At any rate, you can imagine that it is difficult for a troop of 100 or so baboons to hide – and they might want to do so in the Fongoli area, as they are eaten by some of the groups of people living here. Well, the baboons seem to have considered that a foregone solution, and a baboon troop is one of the noisiest bunches of animals you will ever meet – at least in my opinion (with my apologies to the many baboon researchers, should they ever read and take offense at this!).

Yesterday, I followed the party of 15 or so chimps I was with from their nesting site at what we call “Point d’eau” – it is the one permanent water source in their home range at the peak of the dry season (still a month or two away) aside from the Gambia River. After they spent some time out in the woodland, feeding on Keno flowers, they meandered back to the ravine here, which is a small patch of gallery forest where the water hole is situated at the very bottom.The large, noisy troop of baboons decided to drink here as well, and chaos ensued, as it often does when chimps and baboons meet at Fongoli (although one of my project managers has also seen play between young baboons and chimps, as they have at other research sites). Baboons give warning barks (as in predator alarms) to chimps, and there are chases back and forth among the species. It was hard for me to see what was going on in this particular case because I was sitting up the slope some, watching Karamoko (#9 male) sleep for what seemed like hours. Plus, the baboons are afraid of us, while the chimps are not, so often I just get a view of baboons hastily retreating.

In one case last year, the chimp party I was following definitely took advantage of my presence to further chase the baboons back. I was thinking to myself how impressive “our” chimps were although they were outnumbered by these pesky monkeys, when I saw three chimp males run screaming from an adult male baboon! Oh well. To give them credit, baboons do have massive canines, and an adult male looks almost as big as a chimp, although he doesn’t weigh nearly as much…

Another time I did get a better look at baboon and chimp interactions. In this case, a number of the Fongoli male chimps chased back baboons from an area in which they had been foraging. According to what I’ve read by Sharman, baboons in Senegal and chimps feed on many of the same foods (There really hasn’t been much research done on these baboons, Guinea baboons or Papio hamadryas papio, for all you budding primatologists – although there is a project underway by Julia Fisher, a German primatologist). Anyway, this particular encounter involved a subadult male we called ‘Nyegi’ (which means something like “naughty boy” in the Bedik language; this was because he used to follow researchers – especially male ones – and warning bark at us). Nyegi was giving his all in trying to chase baboons away. He threw a number of very large rocks at them. The chimps here throw rocks a lot in their displays, and these are not small stones – usually it takes me two hands to pick one up (see photo of Diouf shot by National Geographic photographer I posted here at left)! The baboons screamed appropriately, as they tend to do, which must have been very satisfying for Nyegi. Sadly, we haven’t seen Nyegi since last spring and he must have almost certainly died. He was a young adult, probably 15 years of age, and we were all excited to see him enter into the adult male hierarchy but never got to see it. Male chimpanzees almost never leave the community into which they were born, so we have reluctantly classified Nyegi as deceased.

To end this blog on an uplifting note though, at the end of the day, the chimpanzee party and baboons ended up sleeping in the same little strip of gallery forest above the water source. I don’t know how much sleep the chimps got – having slept near baboons myself while working in the national park - there always seems to be someone awake and screaming. It seemed like a good ending, though, so I'll imagine that all slept peacefully.