Patterns of wounding in mixed-sex social groups of western lowland gorillas (Gorilla gorilla gorilla)

Long-term, multi-institutional assessments have become a reliable tool for evaluating patterns of wounding in zoo-living primates, with results informing on best practices for species-specific care protocols and population management strategies. For western lowland gorillas (Gorilla gorilla gorilla) there has been no detailed reports focused on mixed-sex groups, the most common social group type for this species in zoos. In this study, wounding data were collected over 26 months for 131 gorillas living in 26 social groups at 18 zoos and analyzed in relation to age, sex, and group demographic variables. Adult females received wounds at significantly higher rates than adult males suggesting sexual dimorphism and the disparate social roles of male and female gorillas may differentially affect wounding rates. Group size was associated with increased wounding in adult gorillas, however, wounding rates overall were low in frequency and severity. Wound locations were not randomly located, with wounds to the trunk accounting for 24 % of all wounds. These data provide useful insights that may help inform and improve management of gorillas in mixed-sex groups. Specifically, understanding that vulnerability to wounding may be more prevalent in females compared to males can inform strategies aimed at improving husbandry, health, and welfare and have a positive impact on population management practices for the species.