I have two short posts this time, one that might be somewhat informative and one that is completely inconsequential and should only be read by those with a desperate need to procrastinate.
Let’s start with the dumb post: I’m beginning to look and to smell like a chimp. I always seem to become aware of this around this time in a field season, when I have just a few more days in the forest before having to re-enter civilization. First, looking like a chimp – this is not much of a stretch for me. My beard always has a somewhat simian-esque quality about it, and now it’s been growing for far too long, as has my hair (I never shave or cut my hair when I’m in the field), so I’m truly entering Dr. Zaius/Planet of the Apes territory. Those of you lucky enough to see me within my first few days back in Minneapolis will get to see this spectacle in all its glory. People occasionally stop me on the streets of Kampala or Fort Portal after I’ve been in the forest for a long stretch of time and say, “Hello, Jesus” (one guy several years back seriously thought I WAS Jesus). As for the chimp smell: chimpanzees have a very distinctive musk – you can smell when they’re in the area – and it’s so pervasive that it remains on the vegetation that they come into contact with. So, if you’re following behind a big group of chimps, passing through the same thick vegetation that they’ve just passed through, well, you’re going to get a bit of chimp aroma on you. Because washing machines are rather difficult to come by in the forest, we re-use our field clothes for a good week or so before washing them, which gives the stench plenty of time to settle on our skin. And, man does that odor like to stick around! We do have “showers” here in camp, which consist of a little shack in which you can bring a pail of water to dump on yourself and, well, you get the idea. It really just sort of moves the dirt around rather than actually gets you clean. So, the chimp-ish smell tends to stay around until I can get access to a good, hot shower (one nice perk of having to go back through Kampala before leaving to go back to the US). Even then the smell seems to linger for a while. I always feel bad for the person sitting next to me on the flight from Entebbe to Amsterdam, and Amsterdam to the US. Those poor folks didn’t know that they were going to be getting occasional whiffs of Eau de troglodytes for 9 hours in a stuffy cabin with poor air circulation. That’s what you get for flying economy class!
OK, now on to the post with at least some substance to it. This one goes out to all you plant aficionados out there (I know there are some of you). I figured, since my primary objective this field season, and one of the primary objectives of my research for the next year or so, is to collect samples of plants fed on by chimps, to analyze their chemical properties and characterize their nutritional quality, I ought to say something about some of the plants in the forest here in Kibale. I mentioned in an earlier post that we are currently experiencing something of a bumper crop of Uvariopsis congensis fruit in this part of the forest. Uvariopsis is a small tree, but it grows in extremely dense groves, with a dozen trees within just a few meters of one another, and chimps can easily move from one to another without having to come to the ground to travel. It is among the most abundant of all trees at the Ngogo site – rivaled only by one or two other species that, interestingly, chimps mostly ignore as food sources. During this particular fruiting event, essentially every Uvariopsis tree in the forest is fruiting (at least all of the trees that I’ve seen), and unlike most fruiting seasons, this one is lasting a LONG time. It’s been going strong for about a month and a half now, and is showing no signs of abating. So, this is a somewhat unusual event, something akin to what plant ecologists working in Dipterocarpaceae forests in Borneo or in oak forests in the eastern US would consider a “mast” fruiting event – virtually all individuals in an area producing fruit (and seed) at the same time. There have been some interesting occurrences that, I strongly believe, are linked to this “masting” event. For example, my old friends the bush pigs seem to be everywhere in the forest these days (not exactly the safest time to be wandering through the forest if you’re a researcher). On a few occasions, I’ve returned to camp in the evening having not obtained a particular plant sample I was hoping to get that day, and David (the only other researcher in camp now) would say something to the effect of, “oh, well tomorrow you should try going out to F/6.5, there’s a big Ficus natalensis out there with lots of fallen fruits”. So, first thing the next day I’d head out to F/6.5 to find the F. natalensis, only to find either a) bush pigs scarfing up all of the fruits on the forest floor, or b) absolutely no fruit on the ground put plenty of pig dung. This has happened a few times and, despite being quite frustrating (it’s not pleasant hiking an hour or more to a particular tree without finding anything there), it’s kind of interesting. Plant ecologists working in Indonesian Borneo, where trees of the Dipterocarpaceae family produce seed during “masting” events once every several years, have proposed that this seed production strategy is an evolutionary response to the threat of seed predation. In particular, in that region, during a dipterocarp masting event, bearded pigs (the primary “predators” of dipterocarp seeds) move into the area in droves. However, the dipterocarp community produces such an overwhelming abundance of seeds that fall to the forest floor, that even with this huge influx of bearded pig vacuum cleaners sucking up all the seeds they can possibly eat, there are still plenty of seeds left intact after the pigs become satiated. Could something similar be going on in the case of Uvariopsis at Ngogo? Produce a huge amount of fruit, much of which will fall to the forest floor, which in turn will draw migratory fruit-eaters (like bush pigs) into the area to feed, and “hope” that they become satiated before all seeds have been gobbled up? Of course, many of the seeds will pass through the gut of the pigs completely intact, and therefore be dispersed. One other intriguing piece of evidence here is that, for the first time that I can remember, there is so much Uvariopsis fruit sitting on the forest floor that much of it is decaying and molding (so obviously not being eaten by any vertebrates). I’ve been working in this forest for over 10 years, and there are still interesting events like this that continue to surprise me.
So, there you have it: one post that might have taught you something, and one that was surely a waste of your time. I guess the two even each other out.