Gorilla Diet

• Western lowland gorillas eat more fruit than the other subspecies; it is readily available within the lower elevations of their range. They are selective feeders that utilize the fruits, stems, flowers, shoots, bulbs, bark, leaves, and pith of over 200 plant species.
• The main difference between the gorilla and the chimpanzee is that when fruits become scarce, the far larger gorilla readilly switches to a fairly coarse diet of ground vegetation.
• Thus, the mountain gorilla's diet consists basically of leaves, bark, pith, coarse stems, roots, vines, bamboo, wild cherry, thistles and nettles, and occasionally insects, snails and slugs.
• Analysis of dung suggests that gorillas choose their favorite fruits for the sugar content, unripe seeds of certain fruits because of low fat content, the stems of plants for fiber, and new leaves for protein (Rogers, 1990).
• Gorillas seldom drink water; their succulent food items provide enough dietary water.
• Gorillas have never been observed hunting or feeding on any animals other than invertebrates such as termites and ants.
• Because gorillas are selective eaters, they never strip a feeding site bare. Adequate vegetation remains for regrowth.
• A gorilla uses its hands and mouth to collect and prepare food.
  

Sources:
Gorilla Natural History — www.selu.com/bio/gorilla/text/nh.html
Seaworld — www.seaworld.org/gorilla/dietgor.html