Action: Primates: Provide live vegetation in planters for foraging.
- One replicated, before-and-after study in the USA reported that chimpanzees spent more time foraging when provided with planted rye grass and scattered sunflower seeds compared to browse and grass added to the enclosure with their normal diet.
Ground cover is important in enclosure design for primates in captivity. This is especially so for species which forage at ground level. Live plant cover aims to encourage natural food items, such as insects, into the enclosures to increase foraging levels.
Supporting evidence from individual studies
A replicated, before-and-after study in 1991 in the USA (Lambeth & Bloomsmith 1994) reported that chimpanzees Pan troglodytes, provided with a foraging device containing planted rye grass and scattered sunflower seeds, spent more time foraging, compared to a feeder containing just grass, with browse added to the enclosure as their normal diet throughout, although no statistical tests were carried out. Chimpanzees foraging behaviour increased from an average of 2% when the feeder contained grass to 12% when the container contained grass with sunflower seeds. PVC pipe cut in half lengthwise and planted with rye grass seed was attached to the outside of six different enclosures containing two or four out of the 14 chimpanzees observed in the study. All chimpanzees in all six enclosures were then given sunflower seeds added to the grass. Behavioural observations over 54 hours were conducted under the two conditions: grass container alone and grass container with scattered sunflower seeds. (CJ)