folivorous

Folivorous describes an animal or other organism whose dominant diet consists of leaves. Leaf-eating is common among various mammals, insects, and some birds, and it often requires specialized anatomical and physiological adaptations to cope with high fiber content, low nitrogen, and plant secondary chemicals.

Leaves are generally rich in fiber and may contain toxins, tannins, and other compounds that deter consumption. Folivores often offset these challenges through extended gut passage times, microbial fermentation, and selective feeding on younger or more nutritious foliage. Many have enlarged digestive tracts or specialized stomachs and caeca that harbor microbial communities capable of breaking down cellulose and extracting nutrients. Some species exhibit slow, energy-conserving lifestyles and low metabolic rates to match the low caloric return of leaves.

Representative examples include mammals such as sloths and koalas, which rely on long, specialized digestive processes to extract nutrients from leaves; certain primates like colobines that possess elongated intestines and complex stomachs; and a variety of folivorous insects, including leaf beetles and many caterpillars, which feed on different plant species. Plants with chemically rich leaves often drive intense plant–herbivore interactions and ecological specialization.

Folivory has shaped evolutionary trajectories, promoting detoxification capabilities, social foraging strategies, and seasonal feeding patterns. It also influences ecosystem dynamics by affecting leaf litter decomposition, plant community composition, and energy flow in habitats where foliage is a primary resource.

See also: folivore, herbivory, herbivore adaptations.