Baboons: A Grasslands Primate
It’s so hard to even think of monkeys that aren’t forest dwellers, but baboons are a group of ground-dwelling grasslanders whose habitat use and social structure might help us learn about our own hominid ancestors. In this episode, Allan combines ecology and anthropology to discuss some grasslands monkeys.
Main Notes and Takeaways
- Primates are a large and diverse order of mammals, with more than ~400 species worldwide.
- Primates are generally associated with forested environments but many species demonstrate an affinity for grasslands, including vervets, patas monkeys, baboons, and more.
- The highly variable and intensely seasonal mosaic environment of the African Savannah presents unique selective pressures to the primates that live there- the same pressures that acted upon our own evolutionary history.
- The six species of baboon are uniquely adapted- physiologically, socially, and cognitively- to such environments, and may give us a lens through which to understand the ecology of early human ancestors such as Australopithecus and Ardipitchecus.
Our Favorite Notes from This Episode
The Best Tasting Biome
The biggest stressors of the savanna boil down to finding food while not becoming food yourself. A complex diet is just one of the many savanna-centric adaptations baboons display to meet these challenges. They are among the most omnivorous of primates. Their diet contains everything from fruit to fish to small mammals, and a hefty portion of grass as well. One study found that yellow baboons (Papio cynocephalus) consumed 47 of the 50 most common grass species in their study area, with grasses making up anywhere from 40 to 90% of their bulk food intake. They are true grass connoisseurs as well, selectively shifting their attention to utilize as many different parts of the plant as they can, from seed to stem to rhizome.
Grasslands Changed Us
Unlike their more strictly arboreal relatives, baboons dwell primarily on the ground in open environments. This shift to a mosaic environment reflects the one made by the earliest human ancestors 6-12 mya, and the anxiety of existing in wide-open spaces may have driven a set of traits to emerge in early hominins that are analogous to today’s baboons. These similarities may provide a useful anthropological framework with which to hypothesize about the ecology of savanna-dwelling hominins like Austrolopithecus.
Baboons live within a complex hierarchical structure that alternates between intensely competitive and vitally cooperative. They work together as smaller family units within larger communities of 10-200 called “troops” to fiercely defend themselves from predators. They maintain relationships within the group to create stability, and use elaborate communication- both vocal and gestural- to interact socially. They possess many of the neurological mechanisms necessary to the origin of language and tool-use. Archeological evidence suggests that early hominins were of similar size to baboons, lived in similar numbers, dealt with the same kinds of predators, and had brain volume resembling modern baboons. Comparing these patterns in baboons and hominins may be a valuable tool in modeling the evolution of our ancestors.
- Fagot, J. et al. 2019. The baboon: A model for the study of language evolution. Journal of Human Evolution, Volume 126, Pages 39-50
- King, G.E. 2022. Baboon perspectives on the ecology and behavior of early human ancestors. PNAS Vol. 119, No. 45
- Norton, G. W. et al., 1987. Baboon Diet: A Five-Year Study of Stability and Variability in the Plant Feeding and Habitat of the Yellow Baboons (Papio cynocephalus) of Mikumi National Park, Tanzania, Folia Primatologica, 48(1-2), 78-120.
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