BeeCam-AprilTag: timing the flight duration of individual honey bees in remote field settings with AprilTag and Raspberry Pi

Understanding the behavior of social species that function as superorganisms requires first examining the behavior of individual members of the colony. We have developed a Raspberry Pi (RPi) and AprilTag-based camera system to record the trip durations of individual honey bees as they exit and re-enter the hive, enabling data collection of hundreds of individuals simultaneously in the context of their environment. This article details the real-time image processing capabilities of our system and the post-processing methods used to determine trip durations. AprilTag detections are collected in real-time as lines in a text file. The trip durations are obtained through a post-processing method that leverages observed honey bee behavior at the hive entrance to identify exits from and re-entries into the hive. For each AprilTag ID, detections are grouped into events. Trips are identified as consecutive “exit” and “enter” events.