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Chimps in Uganda: Reading the Clues

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


A trusted Ugandan colleague called one afternoon to share the news that he had found someone whom I might hire as a field assistant. Jack and I met with our colleague and the prospective hire, Nick, an hour later in town. Nick is a young forestry college graduate with knowledge of local trees and an eagerness that was immediately evident. I offered him the job and our work began soon after.

Upon venturing into the field a couple days later, we found our first and most familiar sign of chimpanzee presence: nests. For the most part, chimpanzees build a new nest each night. These large, leafy beds are constructed by bending branches into a rounded, cushiony shape. The interwoven leaves and branches create a kind of mattress high in the trees.

Nest construction is a skill that takes some time to learn, so young chimpanzees sleep in their mothers’ nests until they are old enough to reliably build their own. Nests of the same age are often found together, evidence that a party, or small group, of chimpanzees slept near each other.


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Finding nests is vital to my research project. Nests provide crucial information regarding where the chimpanzees have been spending their time. This is important because the chimpanzees I study are unhabituated, meaning they are not accustomed to researchers following them closely. Unhabituated chimpanzees typically flee when people come near, as is the case with my study subjects.

For this reason, we must rely primarily on indirect evidence rather than direct observations to better understand their behavior patterns. Luckily, the chimpanzees leave ample clues for us. After we find their nests, we often encounter a second critical clue: their dung. Chimpanzee dung can provide a wealth of information. It can provide insights into what the chimpanzees are eating, how long ago they’ve been in a certain area, and much more. My study relies on these little treasure troves to provide chimpanzee DNA. I will later analyze the DNA to answer various questions about the genetics and behavior of these chimpanzees.

I won’t lie. Collecting chimpanzee dung doesn’t quite fit the romantic, Jane Goodall-in-khaki-shorts image of primatology research that I held some years ago. I remember when my first primate behavior professor, Michele Goldsmith, described studying mountain gorillas in Uganda. As she explained it, seeing gorillas was all well and good, but finding their dung was the real thrill. Like me, she relied on dung samples to provide critical data for her research. Though I knew she was joking a bit, I also couldn’t imagine how finding dung could be so exciting. Now I get it. The highlight of my day often comes when I stumble upon a fresh pile of chimpanzee dung.

Nick listens patiently as I excitedly wax on about the intricacies of poo and demonstrate proper collection technique, then sift through remnants just to see what fascinating discoveries might await us inside our gooey gift from the chimpanzees. I’m certain he must think we’re a bit crazy, especially because direct observations of the chimpanzees have been scarce so far.

Scarce--that is--until yesterday, when we were fortunate enough to have both ample chimpanzee observations and fresh samples to collect. Though we maintained a long distance from the chimpanzees so as not to disturb them, we watched them groom and feed for some time before entering an area they had passed through to see what they left behind. In the process, we found several nests, dung samples, and feeding sites. Data-rich days like these make up for the occasional long days of walking with little or no evidence that chimpanzees aren’t just some figment of our imaginations. For now, I’ll remain satisfied that they exist while continuing to wonder about the many unresolved mysteries of their fascinating lives in these small islands of forest.

Previously in this series:

Chimps in Uganda: Two weeks and counting….

Chimps in Uganda: “These are a few of my favorite things”

Chimps in Uganda: Home Sweet Home

Chimps in Uganda: Bustling Kampala and Unwanted Houseguests

Maureen McCarthy is a PhD Candidate in Integrative and Evolutionary Biology at the University of Southern California. She received her Master's Degree in Experimental Psychology from Central Washington University, where she studied the gestural communication of chimpanzees who have acquired American Sign Language. She has more than a decade of experience studying captive and free-ranging primates. Maureen is currently in Uganda for a year to study the behavioral ecology and genetics of chimpanzees in fragmented forest habitats. Dr. Craig Stanford advises her research. This is Maureen's fourth trip to Uganda--she's been there several times before to volunteer as a research assistant and to collect pilot data for her dissertation. When she's not busy collecting chimpanzee poop or getting malaria, Maureen enjoys birding, hiking, and photography. This research would not be possible without the generous support of the USC Dornsife College of Letters, Arts, and Sciences, the USC Jane Goodall Center, Primate Conservation, Inc., and the American Society of Primatologists.

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