Southern Temptations: Why Did Chimps Sneak Into Neighboring Territory?

View of the southern coast of Gombe National Park on our way to meet up with the venturesome chimps (Photo by Lisa O’Bryan)
The view of the southern coast of Gombe National Park was beautiful on our way to meet up with the venturesome chimps. (Photo by Lisa O’Bryan)

Lisa O’Bryan is in Gombe National Park in Tanzania, where Jane Goodall began the first studies of chimps in the wild. Lisa is in the forest to try to better understand the calls chimps make, to help discover just where the line is (or isn’t) between sounds and speech.

Gombe National Park’s rectangular strip of forest is inhabited by three adjacent communities of chimpanzees named (from north to south) Mitumba, Kasekela, and Kalande. While the Kasekela community is the largest and best-known of these populations, all three communities are regularly monitored.

Recently, we received a radio call from the southern rangers stating that three adult males had been seen, and despite their southerly location, they were members of the central Kasekela community. As my research targets adult Kasekela males, we immediately set off to see what these chimps were up to. After an hour-and-a-half trek due south along the beach and then into the forest we came upon a small party of chimps resting in the trees.

While food is typically more abundant in the northern regions due to greater amounts of rainfall, we found that these males had been attracted south by a plentiful crop of ripe Mpapa fruit (learn more about Mpapa). However, some may have had an ulterior motive as they were in the presence of a sexually receptive adult female, and the alpha male, Ferdinand, was nowhere to be seen. For the rest of the day the chimps ate like kings, and the locally-dominant Titan enjoyed privileged access to the alluring female.

Fudge scans the horizon from inside foreign territory before retreating to the safety of his northern homeland. (Photo by Lisa O’Bryan)

Despite the benefits of food and sex, traveling so far to the edge of the community can be highly dangerous, especially with only three adult males. Given sufficient numerical advantage, chimps will brutally attack and kill those from another community should they meet. However, since it is strongly believed that the southern community no longer has any adult males, we knew our chimps were safe (though it is unclear whether the chimps were as secure in this knowledge). Regardless, they continued to push south throughout the day, crossing well into official Kalande territory.

Finally, in the early evening, the chimps took a breather to survey their surroundings. After gazing across the unfamiliar horizon in the fading light of day, they did a distinct about-face and slowly began retracing their steps. Nesting in the safety of a nearby stream bed, they continued their northerly retreat in the days that followed until arriving back in the core of their home community. Here, I expect they will stay until the temptations of the south lure them back to the periphery.

NEXT: National Geographic Magazine Feature on Bonobos


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Meet the Author
Lisa O’Bryan is a PhD candidate in the Department of Ecology, Evolution and Behavior at the University of Minnesota. Her dissertation research focuses on the function of chimpanzee food-associated calling behavior. She is currently conducting fieldwork at Gombe National Park through the end of May 2013.