Hippos are semi-aquatic megafauna with complex behavioral needs that are challenging to meet in captivity. Understanding their welfare requirements improves management in zoological facilities.
Hippo welfare in captivity centers on two primary requirements: adequate deep water access for their semi-aquatic lifestyle, and appropriate social management. Without sufficient water, hippos cannot regulate skin moisture and temperature, and their characteristic skin secretions serve important protective functions. Social management is complex because the natural social structure of wild hippos - with dominant bulls controlling access to water resources - translates poorly to captive environments where escape from aggression is limited. Facilities must carefully manage group composition to prevent serious injury from inter-individual aggression while meeting the social needs of animals that in the wild exist in complex group structures.