Do Gorillas Live Exclusively in the Forest?

Gorillas cannot survive without forest. They leave the forest only when they are looking for food in the open grassland. Mountain gorillas occasionally climb beyond the tree line: their tracks have been found at 4,000 m altitude.
Gorillas live in primary and secondary forest. Primary forest, i.e. forest largely untouched by humans, is very rich in species. Secondary forest develops in areas that have been cleared of primary forest and is characterised by a few fast growing plant species. Gorillas sometimes raid fields at the edge of the forest. They particularly like the pith of banana trees.