Akers, J. S., Schildkraut, D. S. 1985. Regurgitation/reingestion and coprophagy in captive gorillas. Zoo Biology 4, 99-109.

Coprophagy and regurgitation/reingestion behaviors are so prevalent in captive gorillas because they are by nature foraging creatures. These behavior patterns may therefore be identified as coping strategies. When zoo habitats provide adequate sources of stimulation, coprophagy and regurgitation/reingestion should be dramatically reduced in frequency and duration.