Why Do Leaves Make Up So Much of a Wild Gorilla’s Diet?

Because Goril­las Are Big.

Large mam­malian her­bi­vores, accord­ing to accept­ed eco­log­i­cal the­o­ry, may be expect­ed to feed on abun­dant, low qual­i­ty food as a result of the rela­tion­ship between their body size, meta­bol­ic require­ments, and gut capac­i­ty. … Abun­dant low qual­i­ty food means non­re­pro­duc­tive plant parts, i.e., stems and leaves, because fruit and flow­ers are too ephemer­al to pro­vide a reg­u­lar source of food in bulk for large ani­mals. So, large her­bi­vores ought to be foliv­o­rous in a broad sense, and usu­al­ly are.”


In oth­er words, big plant-eaters main­ly eat leaves.