With visual barriers installed, the drills rested/slept more and were less aggressive towards each other compared to without visual barriers. No clear difference was shown between conditions in social affiliative behaviour and visitor interaction. Stereotypic behaviour in one of the females showed a clear decrease after the installation of visual barriers.

Without visual barriers, all behaviours of the drills where shown to be affected by visitors. Without visual barriers and with increasing visitor intensity, the drills rested/slept less, they were less affiliative and more aggressive towards each other and focused more on visitors. For one of the females, she displayed more of her stereotypic behaviours with increasing visitor intensity. With visual barriers, the behaviours resting/sleeping, social affiliative behaviour and stereotypic behaviour (in one of the females) were no longer affected by visitors. Social agonistic behaviour an visitor interaction showed to still be affected by visitors after the installation of visual barriers.

Being kept outdoors together with feeding enrichment, the drills at Parken Zoo rested/slept less, they were more active, foraged more,focused less on visitors, were less affiliative towards each other and less stressed compared to having both an indoor and outdoor access without feeding enrichment. For one of the females, her stereotypic behaviour clearly decreased in the new condition.