Development and computer-assisted validation of a radio frequency identification system for tracking individual chicken visits to functional areas

Understanding how laying hens interact with functional resources-such as drinkers, feeders, perches, nest boxes, and wintergardens-is essential for meeting their physiological needs and enabling species-specific behaviors. This knowledge is crucial for poultry welfare assessments and precision livestock management. However, traditional ethological data collection methods, including direct observation and manual video analysis, are labor-intensive, prone to observer bias, and impractical for individual-level tracking. To overcome these challenges, we developed and validated an RFID-based system for automated, non-invasive tracking of individual hens' visits to key resources, using an established ArUco-based video annotation system as the reference standard. For validation, twenty-one laying hens were fitted with RFID leg bands and 3D-ArUco markers and monitored over five days in a mobile barn setup equipped with ultra-high-frequency RFID antennas. Alignment between data from the RFID and 3D-ArUco systems allowed calculation of performance metrics such as the F1-score-defined as the harmonic mean of precision and sensitivity-for visit durations and event detections (i.e., entries and exits), and the coefficient of determination (r²) for visit counts. Wintergarden showed the highest performance (84 % F1-score, 93 % r²). Metal perch achieved F1-scores of 79 % and 86 % for access and leaving events. Nest boxes showed intermediate performance (78 % F1-score, 77 % r²), while drinkers and feeders were lower (64 % F1-score each; r² values of 69 % and 49 %). These findings confirm RFID's potential for tracking visits to wintergardens, perches, and nest boxes-demonstrating sufficient performance for practical use, though further optimization through antenna positioning remains possible. For feeders and drinkers, however, accurate tracking remains challenging, and complementary technologies may be required, as rapid movements reduce tag dwell time, overcrowding causes signal interference, and open areas increase misreads from nearby surrounding movement. This study highlights RFID's value for behavioral research at the individual level in poultry and supports research-driven innovation in housing equipment design. It also demonstrates how a computer-assisted approach can facilitate validation across diverse behavioral contexts.