Published online by Cambridge University Press: 11 January 2023
An attempt was made to encourage more foraging behaviour in eight pair-housed adult rhesus macaques (Macaca mulatta). No special device and no special food were used Daily commercial dry food rations (238g per animal) consisting of 33 bar-shaped or 16 star-shaped biscuits per animal were placed on the mesh ceiling of the cages instead of in the feed-boxes. This induced an 80-fold increase (17.0 vs 1362.9s) and 289-fold increase (12.3 vs 3551.4s), respectively, in foraging time. The animals spent on average 9.6 per cent and 24.7 per cent respectively, of four-hour observation sessions foraging for biscuits from the mesh ceiling. Working for their food did not discourage them from eating all left-overs in the course of a day regardless of the shape of the biscuits.
It was concluded that the new feeding procedure enhanced the animals’ behavioural well-being by encouraging foraging activities thereby helping to counteract understimulation.