Effects of animate vs. inanimate stimuli on curiosity behavior in greater galago and slow loris

Abstract

Captive prosimians housed in a semi-natural laboratory environment were exposed to novel stimuli, both animate (cat, snake) and inanimate (empty box). Observations were made by means of closed circuit TV. Animate stimuli elicited considerably more interest (about 42% of a test session) than the inanimate stimulus (about 12% of the test session). The more vulnerable species, the slow loris, displayed as much curiosity as the less vulnerable species, the greater galago; but, in the presence of live stimuli, lorises were more cautious. They moved slowly and silently, employed contact as a mode of investigation significantly less often than galagos, spent significantly less time than galagos investigating from within 3 ft, took significantly longer than galagos to make their first approaches to within the 3 ft zone, and, once there, stayed for significantly shorter visits than galagos. The data demonstrate: (1) that prosimians are highly responsive to novelty if the stimuli are appropriate; and (2) that it is important to take into account not just whether animals investigate but also how they investigate.