Fresh nests and fecal samples. We knew the chimpanzees had nested nearby. Not having seen any signs of their continued presence, however, we assumed they had already left their nests and traveled elsewhere to forage. While examining the nests, we were startled out of concentration by a chorus of pant hoots just nearby. We looked in the direction of the calls. A few chimpanzees were in a fig tree not far away, eyeing us calmly as they stuffed figs into their mouths. We watched them for a few minutes until they climbed down from the fig and traveled along the ground through a nearby bit of forest. After we were certain they were gone, we continued checking for samples, including looking around the fig they left behind.
This is not the first time we’ve been surprised by the chimps. Sure, they can be boisterous and loud. There are times when they’re downright impossible to miss. On other occasions, however, they are so quiet that we can pass right by them and almost fail to notice them. I often wonder how many times we actually have failed to notice them.
So went December. It was a busy month that brought lots of data, including a few surprise encounters with the chimpanzees. Surprises, though inevitable, are not the norm for us. Our direct chimpanzee observations often involve getting reports from farmers who tell us that the chimpanzees are in a nearby tree or patch of forest. When we find chimpanzees, we make every possible attempt to give them their space. We keep a distance of over 50 meters and view them through binoculars. We do not enter an area of forest when we know that they are just inside within 50 meters.
Instead, we wait until we are reasonably certain that they have departed before entering to look for samples. This is very important since these chimpanzees are not habituated, meaning they are not accustomed to being followed by people for research or tourism purposes. (See another recent Scientific American blog post for additional discussion of habituation and its role in our understanding of chimpanzees.) Habituated chimpanzees can be followed at close range and are—hopefully—undisturbed by human presence. Habituation is necessary to undertake long-term research that provides meaningful insights into the behavior patterns of chimpanzees.
Studying unhabituated chimpanzees means that I can’t rely on close behavioral observations for data collection. The chimpanzees I study typically flee if people come near. This is why I focus on indirect evidence like fecal samples to provide critical data. Even with only some behavioral observations, however, the chimpanzees provide a wealth of information for study. Their nests provide insights into where they choose to sleep, their feeding remains show us what they’ve been eating, their knuckle prints tell us which direction they’ve traveled, and their dung provides…well, all sorts of interesting information.
Studying unhabituated chimpanzees also means that I must take care to avoid causing undue stress to my study subjects. Because these chimpanzees live in small forest patches, they have limited space to flee if we come too close for their comfort. It is for this reason that we keep our distance and enter onto their turf only after they’ve left it.
Given the importance of habituation for actually being able to watch the animals under study, one may wonder why I have chosen not to habituate these chimpanzees. There are several reasons. First, chimpanzee habituation is typically a long and arduous process. It can take one to two years or more, if feasible at all. As a lowly PhD student, I simply do not have the time or resources to undertake such a costly endeavor. More importantly, however, the risks of habituation for these chimpanzees may outweigh the benefits. Because they are often in conflict with the humans around them, being wary of people may actually work in their favor. The more comfortable they become with people, the more they may be at risk of aggressive encounters with their human neighbors.
My colleague Matt McLennan (as mentioned in previous posts) has cautioned against habituating chimpanzees in our study region for ecotourism, saying that “habituation for tourism is inappropriate where apes and people live in very close proximity, for reasons that include increased likelihood of crop-raiding, risk of aggression toward local people and tourists by emboldened and/or stressed chimpanzees, and increased potential for disease transmission. Instead, habitat stabilization and enrichment must be the priority” (McLennan 2008, p. 52).
This study region is not unique in posing ethical concerns regarding the primates inhabiting it. Primatologists around the world must consider the ethical implications of various research methods, and design their studies accordingly. Just as lab scientists must consider potential risks to their study subjects in an effort to minimize harm, so must field scientists consider the potentially negative impacts of their research. Collecting data is only one aspect of the job. Personal, ethical, and emotional rewards and challenges are a part of everyday life. For me, this is what makes research an exciting, layered, and often imperfect experience.
Previously in this series: