The response of group-housed baboons to three enrichment toys.

The behaviour of group-housed baboons was compared before and after the provision of durable cage toys. One adult male hamadryas baboon and 13 adult female olive baboons living in a large enclosure were observed after they were given seven nylon bones, seven Kong toys and seven Plaque Attackers. Observations were conducted four times per week on each subject over a 6-week period. Abnormal, cage-directed, inactive and self-directed behaviours all significantly decreased after the provision of the toys, while enrichment-directed activities significantly increased. Aggression did not differ between the no toy and toy conditions. Approximately 26% of the baboons were using the toys at any one time, and use of the Kong toys and the bones was higher than that of the Plaque Attackers. Individuals who used enrichment structures already present were also those who used the new toys the most.