Regurgitation and Reingestion in Captive Great Apes

Two male western lowland gorillas (Gorilla gorilla gorilla) and one female northwest Bornean orangutan (Pongo pygmaeus pygmaeus) at Omaha’s Henry Doorly Zoo and Aquarium have exhibited recurring regurgitation and reingestion (R&R) behavior. No negative health effects have been noted related to this behavior in the two gorillas; however, the orangutan has had multiple cavities that are suspected to be related...

Cholesterol concentrations in free-ranging gorillas (Gorilla gorilla gorilla) and (Gorilla beringei) and Bornean orangutans (Pongo pygmaeus)

Cholesterol concentrations in captive gorillas and orangutans vary widely within species and average approximately 244 mg/dl for gorillas and 169 mg/dl for orangutans as previously published. The International Species Inventory System reports higher concentrations of 275 and 199 mg/dl for gorillas and orangutans, respectively. It is unknown if these values were typical and/or were influenced by captive management. To answer...

Removing milk from captive gorilla diets: the impact on regurgitation and reingestion (R/R) and other behaviors

To test whether milk consumption facilitates performance of regurgitation and reingestion (R/R) in captive gorillas, an experiment was conducted in which milk was removed from the gorilla diet at Zoo Atlanta. The study was conducted using a withdrawal design (BTB), in which a baseline period (B) of 10 days was followed by a treatment period (T) of 10 days, followed...