Computer-enabled screen systems containing visual elements have long been employed with captive primates for assessing preference, reactions and for husbandry reasons. These screen systems typically play visual enrichment to primates without them choosing to trigger the system and without their consent. Yet, what videos primates, especially monkeys, would prefer to watch of their own volition and how to design computers and methods that allow choice is an open question. In this study, we designed and tested, over several weeks, an enrichment system that facilitates white-faced saki monkeys to trigger different visual stimuli in their regular zoo habitat while automatically logging and recording their interaction. By analysing this data, we show that the sakis triggered underwater and worm videos over the forest, abstract art, and animal videos, and a control condition of no-stimuli. We also note that the sakis used the device significantly less when playing animal videos compared to other conditions. Yet, plotting the data over time revealed an engagement bell curve suggesting confounding factors of novelty and habituation. As such, it is unknown if the stimuli or device usage curve caused the changes in the sakis interactions over time. Looking at the sakis’ behaviours and working with zoo personnel, we noted that the stimuli conditions resulted in significantly decreasing the sakis’ scratching behaviour. For the research community, this study builds on methods that allow animals to control computers in a zoo environment highlighting problems in quantifying animal interactions with computer devices.

Figure 1: Prototyping buttons with white-faced sakis: (a) B1: doorknob touch button, (b) B2: push button, (c) B3: doorknob push button, (d) B4: pull-rope pull button, (e) B5: metal plate touch button, (f) B6: ball pull button, (g) B7: lever push button, (h) B8: swinging panel button, (i) B9: upgraded swinging panel button, (j) monkeys testing the ball pull button f.

Figure 1: White-faced saki monkeys using the interactive device. Left: an image from the camera inside the device. Middle: the three interactive zones of the device. Right: the device inside the monkeys' enclosure.