Prevalence of regurgitation and reingestion and occurrence of coprophagy in the North American AZA Gorilla ( Gorilla gorilla gorilla ) population

The aims of this study were to determine the current prevalence of regurgitation and reingestion (R/R) and gain an insight on the occurrence of coprophagy in the Association of Zoos & Aquariums (AZA) gorilla (Gorilla gorilla gorilla) population. To do this, an online survey was sent to all AZA accredited gorilla institutions in 2018. This survey collected information on the severity of R/R at the individual level and the occurrence of coprophagy at the zoo level. Previous research suggests more than half of zoo-housed gorillas in the North American population engaged in R/R and coprophagy to some extent. The current study had a 100% response and completion rate; data were collected on all 296 noninfant gorillas in the population. Responses indicated that 60% of the AZA gorilla population engages in R/R to some degree and 24% of the population are observed exhibiting coprophagy on a weekly basis. With this preliminary information on coprophagy, and the realization that the Zoo community has been unsuccessful at eliminating R/R over the past 30 years, the next steps should be aimed at empirically assessing the potential drivers of these behaviors. Continuing efforts to further understand and eliminate R/R and coprophagy in zoo-housed primates is important not only because these behaviors are unsightly to visitors, but more importantly, R/R and coprophagy may signal deficiencies in current practices surrounding animal care.