June 17, 2015
Why males? I ask myself. Three hours have passed since Sheldon, the target of my behavioral follow, climbed to the top of a palm tree. He sits and feeds where the fronds gather in a cluster before arcing out in all directions to swoop and sway in the passing breeze. I lie on the ground, pack resting beneath my head, and as the time ticks away in five minute intervals I fill row after row of data with feeding, feeding, feeding. Somewhere in the interim I reach a point of boredom so severe that I am compelled to pass the time with aerobic exercises, and I begin a series of lunges, leg lifts and squats. Cosmas looks on, observing my behavior as if I were another species altogether, perhaps the curious subject of his own data collection, before I realize my spectacle and try to explain.
Must make exercise or I will have too many fat, I artfully retort. Cosmas responds…
…or you could just eat less.
Touché. The day is far from over and I have already devoured one granola bar, a bag of cashews and a honey-smothered chapati that I managed to ferret away from the kitchen and into the forest. In the absence of a counter-point, I scoff and take solace in Sheldon, who will likely devote over half of his day to caloric intake. He doesn’t seem to mind, so I don’t either. I sit back down, ushering in a new wave of boredom, and resume questioning why on earth I chose to study adult males, a chimpanzee demographic with possibly the most monotonous solitary behaviors of all time.
This question has a technical answer: Male chimpanzees are known to engage in conspicuous aggressive interactions, making them the ideal study subjects for any research project intending to explore the nuances of conflict or cooperation. Males form short-term, aggressive coalitions , and compete with one another for access to females . In particular, high-ranking males demonstrate elevated rates of escalated aggression compared to subordinates . And that’s just a little aggression among friends! Encounters between males from different groups can be so violent that these interactions have been likened to human warfare. In fact, 1970’s Gombe was met with what would become one of the better known conflicts in chimpanzee history, the Four-Year War*. Beginning in 1974, individuals from Kasekela attacked and killed a young male from the southern Kahama community, the first observation of chimpanzees intentionally killing a member of their own kind. Over the next four years, Kasekela males brutally eliminated the remaining six adult males and expanded their borders by several valleys . As a result, the Kahama community no longer exists, a cruelty leading some researchers to posit that chimpanzee males are genetically predisposed to violence .
But watching Sheldon laze about in a palm tree, languidly ushering food into his mouth while simultaneously scratching his belly, one is hardly reminded that he hails from the great war heroes of Gombe past. Granted he is alone, but overall Sheldon seems about as far from “demonic”  as they come; he occupied the alpha position for only two years, which is quite short, considering Frodo’s infamous six-year reign of terror. In addition, Sheldon is frequently spotted playing with unrelated infants, and, on an anthropomorphic note, he likes to sport a goofy half-grin whenever he is staring off into the distance (and presumably day-dreaming). Somehow, spending time with this massive male chimpanzee is less havoc at the hands of a militarized combat machine and more brunch with an unapologetically hungry gal pal. Like me, he appears to always choose feeding over fighting, and as I recline, I realize that he is without a doubt my favorite chimp in the group. I pull out another granola bar and conclude that it really is true what they say:
If you can’t beat ’emƚ, join ’em…
* Readers ignorant to this pivotal event should not feel lacking in culture. Your textbooks were likely preoccupied with human dealings at the time, particularly those taking place in Vietnam. Being without flags, draft cards, bras, or pot, the chimpanzees of Gombe had nothing to burn, and thus their wars and accompanying protests have been historically overlooked. To the author’s knowledge, the only musical artists to ever commemorate the Four-Year War were the Black Eyed Peas, who, 30 years later, asked “Where is the Love?”
ƚ Beat ’em is never an advisable strategy when the subject in question is a wild chimpanzee.
1] Gilby, I.C., Brent, L.J.N., Wroblewski, E., Rudicell, R.S., Hahn, B.H., Goodall, J. and Pusey, A.E. (2013) Fitness benefits of coalitionary aggression in male chimpanzees. Behavioral Ecology and Sociobiology 67, 373–381.
2] Goodall, J. (1986) The chimpanzees of Gombe. Harvard University Press.
3] Muller, M.N., and Wrangham, R. (2004) Dominance, cortisol and stress in wild chimpanzees (Pan troglodytes schweinfurthii). Behavioral Ecology and Sociobiology: 55:332–340.
4] Feldblum, J. T., Manfredi, S., Gilby, I. C., and Pusey, A. E. (2014) Politics by other means: Social networks, community identification, and the “Four Years’ War” in the chimpanzees of Gombe National Park, Tanzania. Podium presentation at the 2014 American Association of Physical Anthropologists meeting, Calgary, ON.
5] Wrangham, R. W., and Peterson, D. (1997) Demonic males: Apes and the origins of human violence. Houghton Mifflin Harcourt.