A real-time 3D video tracking system for monitoring primate groups

• We developed a 3D video system to measure behaviors of socially-housed primates.
• Validation was performed by comparing 120 h of automatic to manual scoring.
• The system allowed quantifying different social profiles of colony members.
• Measurement of toy manipulation is introduced as a paradigm for hierarchy assessment.

To date, assessing the solitary and social behaviors of laboratory primates’ colonies relies on time-consuming manual scoring methods. Here, we describe a real-time multi-camera 3D tracking system developed to measure the behavior of socially-housed primates. Their positions are identified using non-invasive color markers such as plastic collars, thus allowing to also track colored objects and to measure their usage. Compared to traditional manual ethological scoring, we show that this system can reliably evaluate solitary behaviors (foraging, solitary resting, toy usage, locomotion) as well as spatial proximity with peers, which is considered as a good proxy of their social motivation. Compared to existing video-based commercial systems currently available to measure animal activity, this system offers many possibilities (real-time data, large volume coverage, multiple animal tracking) at a lower hardware cost. Quantitative behavioral data of animal groups can now be obtained automatically over very long periods of time, thus opening new perspectives in particular for studying the neuroethology of social behavior in primates.