Prevalence of Regurgitation and Reingestion in Orangutans Housed in North American Zoos and an Examination of Factors Influencing its Occurrence in a Single Group of Bornean Orangutans

Very little research has explored regurgitation and reingestion (R/R) in orangutans. We first aimed to determine the prevalence of R/R in the North American zoo population through a survey of accredited institutions. We report the prevalence of R/R in orangutans >4 years of age as 35% with some sex and species differences. Additionally, survey respondents […]

Implementing a low-starch biscuit-free diet in zoo gorillas: The impact on behavior

In the wild, western lowland gorillas travel long distances while foraging and consume a diet high in fiber and low in caloric density. In contrast, gorillas in zoos typically consume a diet that is low in fiber and calorically dense. Some items commonly used in captive gorilla diets contain high levels of starch and sugars, […]

Hair plucking in captive bonobos (Pan paniscus)

Both wild and captive studies of grooming in non-human primates emphasize the adaptive role of this behavior. Indeed, social grooming is frequently characterized as “social glue” in the life of primates. Grooming behavior is studied to reveal dominance, kin relations, and social networks. Many captive primates, including apes, are observed to over-groom which may result […]

Hair plucking, stress, and urinary cortisol among captive bonobos (Pan paniscus)

Hair plucking has been observed in many captive primate species, including the great apes; however, the etiology of this behavioral pattern is poorly understood. While this behavior has not been reported in wild apes, an ethologically identical behavior in humans, known as trichotillomania, is linked to chronic psychosocial stress and is a predominantly female disorder. […]