Background information and definitions
Releasing live insects or other invertebrates into enclosures aims to encourage more natural foraging behaviour in primates which hunt live prey in the wild. Live insects attract the attention of the primate, encouraging natural behaviours such as chasing, stalking and pouncing.
Supporting evidence from individual studies
A before-and-after study in 2015 in the UK (Williams et al. 2015) found that when live insect prey were provided to captive loris Loris lydekkerianus nordicus inactivity was reduced and foraging increased to levels seen in wild lorises. Average inactivity time reduced from an average of 46% to 29% (wild loris averaged 43%) and average foraging time increased from 9% to 24% (wild loris averaged 27%). In addition, a significant increase in postures used in foraging in the wild and a wider behavioural repertoire was seen by recording positional behaviours. Observational data was collected over five consecutive days at five-minute intervals over six hours/day for each of the five animals for each of three conditions: pre-enrichment (usual diet); enrichment (usual diet plus live insects); and post-enrichment (usual diet). Approximately 200 crickets were scattered into an indoor enclosure at 10:00 h over the five days of the enrichment condition (approximately 40 each day) in addition to their normal diet. (CJ)Study and other actions tested