How Primates in Tanzania Reveal the Hidden Role of Mushrooms in Early Human Diets

The overlooked food source

When thinking of primate diets, most imagine sweet fruits, tender leaves, and perhaps the occasional insect. Yet on the savanna-woodland mosaic of western Tanzania, mushrooms are emerging as an unexpected player in the seasonal diets of baboons, chimpanzees, and red-tailed monkeys.

Baboon eating a wild mushroom. Credit: E. McLester/GMERC

For four years, an international team of researchers observed these three species in the Issa Valley. By documenting¹ over 50,000 feeding events, they discovered that mushrooms—though making up a small share of total calories—shape how each species negotiates seasonal scarcity and competition.

“Our analysis shows that three coexisting primate species exploit fungi in different ways,” the authors report. “This dietary partitioning likely reduces competition and reveals how overlooked foods help maintain complex ecological communities.”