Mycophagous

Fungivory or mycophagy is the process of organisms consuming fungi. Many different organisms have been recorded to gain their energy from consuming fungi, including birds, mammals, insects, plants, amoeba, gastropods, nematodes, bacteria and other fungi. Some of these, which only eat fungi, are called fungivores whereas others eat fungi as only part of their diet, being omnivores.

Many mammals eat fungi, but only a few feed exclusively on fungi, most are opportunistic feeders and fungi only make up part of their diet. At least 22 species of primate, including humans, bonobos, colobines, gorillas, lemurs, macaques, mangabeys, marmosets and vervet monkeys are known to feed on fungi. Most of these species spend less than 5% of the time they spend feeding, eating fungi and they therefore form only a small part of their diet. Some species spend longer foraging for fungi and they account for a greater part of their diet; buffy-tufted marmosets spend up to 12% of their time consuming sporocarps, Goeldi’s monkeys spend up to 63% of their time doing so and the Yunnan snub-nosed monkey spends up to 95% of its feeding time eating lichens. Fungi are comparatively very rare in tropical rainforests compared to other food sources such as fruit and leaves and they are also distributed more sparsely and appear unpredictably, making them a challenging source of food for Goeldi’s monkeys.

Fungi are renowned for their poisons to deter animals from feeding on them: even today humans die from eating poisonous fungi. A natural consequence of this is the virtual absence of obligate vertebrate fungivores. One of the few extant vertebrate fungivores is the northern flying squirrel, but it is believed that in the past there were numerous vertebrate fungivores and that toxin development greatly lessened their number and forced these species to abandon fungi or diversify. Although some monkeys still eat fungi today, there are no completely fungivorous primates, though their dentition is very suitable for eating fungi.

...
Wikipedia