Sandhaus EA, Bashaw MJ, Faith NS, Barnhart T, Davis Leith H, Nursement C, Ortega V, Beem L, Bailey A, and Barnes J. 2021. Effects of dietary composition on behavior of male gorillas at the Santa Barbara Zoo. In Brooks M, Koutsos E, and Henry B Eds. Proceedings of the Fourteenth Conference on Zoo and Wildlife Nutrition, Zoo and Wildlife Nutrition Foundation and AZA Nutrition Advisory Group, Virtual.
Regurgitation and reingestion (R/R), a behavior that is observed in gorillas in human care but not in their wild counterparts (Lukas et al., 1999), remains poorly understood and is likely multifactorial in origin (Hill, 2018). Western lowland gorillas (gorilla gorilla gorilla) consume over 200 species and varieties of plants and 100 species and varieties of fruit (Popovich et al., 1997), and this dietary diversity and associated foraging time is not easily replicated in human care. In 2017–2018, two bachelor western lowland gorillas at the Santa Barbara Zoo were transitioned to a low-starch biscuit-free diet (Less et al., 2014) to elicit a reduction in R/R. Here we quantify rates of R/R as well as effects on overall activity budget when biscuits were subsequently reintroduced into the diet in Spring 2021 due to weight management and other husbandry considerations, followed by a return to baseline. Implications for behavioral management of this critically endangered ape in human care will be discussed.38_Sandhaus.pdf     115 KB