First record of Peruvian spider monkeys (Ateles chamek) feeding on a known mushroom species, Oudemansiella canarii (Physalacriaceae)

A large group of Peruvian spider monkeys, Ateles chamek, was recorded feeding on Oudemansiella canarii mushrooms in Madre de Dios, Peru. The observed spider monkeys were seen foraging for mushrooms on the forest floor where they grew on downed logs. Spider monkeys are ripe fruit specialists that rarely venture to the forest floor, suggesting that these mushrooms could represent an important though seldom consumed food source. Previous accounts of spider monkeys consuming mushrooms are sparse and do not include identification of the fungi. O. canarii mushrooms have a relatively high protein content, possible immunological benefits, and are present during times of relative fruit scarcity in the region. These reasons could explain why the spider monkeys risked a visit to the forest floor to forage for O. canarii mushrooms.