In the wild, western lowland gorillas (Gorilla gorilla gorilla) most often live in groups of one silverback male, multiple females, and their offspring. Given that gorillas have roughly equal sex ratios at birth, there are numerous captive males for whom female social partners are not available. These males are often housed together in all-male, “bachelor” social groups as an alternative to being housed alone.
The Detroit Zoo houses a bachelor group of three silverback gorillas. Using behavioral and hormonal data, we are working to better understand how living in a captive bachelor group impacts each gorilla. Specifically, we investigated how stress levels and social dynamics change depending on whether the gorillas are housed indoors, outdoors, or if they have access to both indoor and outdoor habitats.