Modifying the behaviour of singly caged baboons: evaluating the effectiveness of four enrichment techniques (2005)

Bourgeois, S. R., Brent, L.

Abstract

Seven singly caged adolescent [mean age: 4.2 years] male baboons were studied. Analysis of baseline behaviour verified substantial durations of abnormal behaviour [9.8/30- min observations (33% of time)]. We tested the effectiveness of ... positive reinforcement training (PRT), food enrichment [fruits, frozen fruit/juice, foraging devices], non-food enrichment [toys], and social enrichment (pair/trio). ...The social enrichment condition resulted in the most positive behavioural changes, including ... near elimination of abnormal behaviours [0.7/30-min observation (2% of time)]. Significant reduction in total abnormal behaviour levels were also found for other types of enrichment, but only social enrichment and PRT were effective in reducing whole-body stereotypies. ... Animate enrichment (human or conspecific stimulation), as opposed to inanimate enrichment, provides optimal means of behaviour modification for singly caged baboons.Pairs were formed by introducing sedated partners in the same cage. Pairing was successful for all seven individuals, with no serious injuries or overt aggression observed.