Mandrills are large, terrestrial primates that require substantial outdoor space with varied terrain for natural locomotor and social behaviour in zoo settings.
Mandrill welfare requires outdoor space that allows meaningful locomotion and exploration. Indoor holding that restricts groups to small spaces for extended periods causes welfare deterioration through reduced activity and increased aggression. Naturalistic outdoor habitats with varied terrain, vegetation and novel features support cognitive engagement, natural locomotion and group social dynamics. Seasonal restriction to indoor facilities must be minimised through appropriate outdoor design.