Individual study: An Enrichment Device for Great Apes
Gilloux I., Gurnell J. & Shepherdson D. (1992) An Enrichment Device for Great Apes. Animal Welfare, 1, 279-289
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Primates: Present food in puzzle feeders
A before-and-after study in 1992 in the UK (Gilloux 1992) found that presenting food in puzzle feeders increased foraging behaviour and the use of tools in chimpanzees Pan troglodytes, gorillas Gorilla gorilla gorilla, and orangutans Pongo pygmaeus pygmaeus compared to food being placed in the enclosures. The percentage feed orientated behaviour, including tool use, increased from 2% when food was placed in the enclosure to 30% when a puzzle feeder was introduced to orangutans, 2% to 20% for gorillas and 3% to 30% for chimpanzees. An open-ended 3 m length of 15 cm diameter plastic drain pipe, attached horizontally to the outside of the enclosure weldmesh, was used with each group of apes (four gorillas, seven chimpanzees and two orangutans) studied for 12 two-hour trials with food placed into the enclosure and 12 two-hour trials with food in the feeder. (CJ)