Active vision during prey-capture in wild marmoset monkeys

Here, we examined prey-capture in wild common marmosets ( Callithrix jacchus ) to explicate the active role of primate vision for high-precision, goal-directed motor actions in challenging natural environments. We observed distinct marmoset hunting strategies that each relied on the close integration of visual processes and dynamic biomechanical motor movements, but differed based on several factors including prey size/speed, substrate, and their relative distance to the prey. Marmoset positional behavior in these complex arboreal settings often involves extending the body, including inversions, while relying on vision to guide prey capture. Applying markerless pose estimation technology, analyses revealed details of how primate vision both guides and corrects rapid motor actions in real-time during prey-capture in the wild. These findings illustrate the significance of active vision during primate ethological behaviors in response to the very challenges the visual system evolved to solve.