Action: Primates: Hide food in containers (including boxes and bags)
This intervention involves using boxes or bags to hide daily meals given to monkeys. This would normally be put in bowls or scattered within an enclosure, but instead it is put within a box or bag hidden within browse, with the aim of increasing foraging behaviours in individual monkeys.
Supporting evidence from individual studies
A before-and-after study in 2005–2006 in the USA (Dishman et al. 2009) found that adding browse to hide food in boxes significantly raised activity levels in ring tailed lemurs Lemur catta compared to when browse was presented on the floor of the enclosure along with food presented at a regular feeding station. Adding browse to food in boxes more than doubled (to 79%) the percentage of observation periods when at least one lemur was active. It also increased the percentage of active behaviours during that period from 4% of observations to 13% of observations. Spatially separating the four boxes reduced the amount of food that lemurs stole from other animals in the mixed enclosure by half (0.2% of observations to 0.1% of observations). The lemurs were presented with four treatments: food was added to four open boxes placed together and browse scattered on the floor of the enclosure; food scattered in the browse and added to boxes placed together; food added to boxes placed apart and browse scattered on the floor; food scattered in the browse and added to boxes placed apart. A group of eight lemurs, living in a mixed enclosure with hyrax and porcupine, were scanned every 60 seconds for two hours per day over six days and behaviours recorded. Boxes were given to the lemurs every day, with a different treatment given each day. (CJ)
A before-and-after study in 2009 in Ireland (Wells & Irwin 2009) found that when food was presented in food filled baskets or presented in tubes foraging of moloch gibbons Hylobates moloch increased and time spent outside the indoor enclosure increased compared to when fresh fruit and vegetables were presented in one place. With the food filled baskets significantly more instances of being outside and number of times gibbons were seen foraging were recorded when food filled baskets were presented (times outside: 106; times foraging: 44) compared to when fruit and vegetables were offered alone (times outside: 96; times foraging: 20). With the tubes significantly more instances of being outside and the number of times gibbons were seen foraging were recorded when food filled tubes were presented (times outside: 112; times foraging: 43) compared to when fruit and vegetables were offered alone (times outside: 96; times foraging: 20). A group of gibbons was presented with food in baskets or tubes for five days, with three baskets or tubes suspended within the animal exhibit each time. The gibbons’ behaviour was recorded every five minutes for five hours per day for 12 days. (CJ)
- Dishman D.L., Thomson D.M. & Karnovsky N.J. (2009) Does simple feeding enrichment raise activity levels of captive ring-tailed lemurs (Lemur catta)? Applied Animal Behaviour Science, 116, 88-95
- Wells D.L. & Irwin R.M. (2009) The Effect of Feeding Enrichment on the Moloch Gibbon (Hylobates Moloch). Journal of Applied Animal Welfare Science, 12, 21-29