Multibehavioral analysis of fear and anxiety before, during, and after experimentally induced predatory stress in Callithrix penicillata.

A detailed behavioral analysis of nine Callithrix penicillata was conducted in the Marmoset Predator Confrontation Test (MPCT) during (a) four habituation trials with no "predator," (b) six confrontation trials with the predator (taxidermized oncilla cat, Felis tigrina), and (c) four trials with the predator removed. The marmosets habituated to the test apparatus with significant decreases in locomotion, exploration and long calls. Initial exposure to the predator elicited mainly fear-related behaviors (proximic avoidance, tsik-tsik vocalization, swaying/tongue in-out), whereas repeated confrontations attenuated these behaviors, concomitant to an increase in anxiety-associated responses (scratching/grooming/scent marking). The initial behavioral repertoire, observed before confrontations, was fully restored only upon removal of the predator. This easily discernable complex defensive behavioral repertoire is hoped to provide a comprehensive baseline for studying the biological substrates of fear/anxiety parameters in nonhuman primates.