Hippos spend most of their day partially submerged and have complex social structures. Zoo management must accommodate their aquatic lifestyle and social needs.
Hippo welfare in zoo settings requires substantial water areas for daytime submersion, appropriate social groupings, and safe management of potentially aggressive animals. Facilities without adequate water depth and area for natural thermoregulation compromise fundamental welfare needs. Their complex social structure means housing incompatible animals together causes severe stress and injury risk. Night grazing behavior should be accommodated by providing access to large land areas for natural movement. Advanced facilities provide naturalistic mixed-sex groups with careful population management, large water features, and extensive land areas for nocturnal grazing. Security requirements for hippo management are significant given their power and potential for aggression.