Videostimulation as enrichment for captive rhesus monkeys (Macaca mulatta)

Visual stimulation may be an ideal, though often underutilized, means by which to enrich the environment of captive monkeys. Here, we compared the reactions of both socially and individually housed rhesus monkeys to 2 types of videostimulation-videotapes and a video game. We determined whether the monkeys used the devices, exhibited other changes in their behavioral repertoire and showed signs of habituation. Nine monkeys were exposed to 5 experimental phases in the following order: no monitor, blank monitor, videotape, blank monitor and video game. In the Videotape phase, each of 4 h-long tapes was shown for 5 days, totalling 20 days of exposure. In the video game phase, monkeys had access to this device for 13 days. Data were collected during 1 h test sessions using a scan-all, point sampling method in which the behavior and cage location of each subject within a group was recorded every 15 s. Our measures of usage clearly indicated that monkeys both watched selected videotapes and manipulated the video game joystick. However, monkeys spent substantially more time watching videotapes than manipulating the joystick, and females showed more interest in these devices than males. Exposure to these devices also affected other behaviors. Both socially and individually housed monkeys became more active. The social subjects displayed lower levels of passive social contact and higher levels of locomotion during device presentation. Individually housed monkeys slept less. There was little evidence of habituation to either device in females. Males, however, displayed some habituation to videotapes but not to the video game. These results suggest that videostimulation in the form of videotapes and/or video games may be successful forms of enrichment for captive rhesus monkeys.