Comparing the behavioural organization of head pecking, severe feather pecking, and gentle feather pecking in domestic turkeys

Detection of behavioural temporal patterns (T-patterns) allows for insight into the organization of behaviours that is not apparent through quantitative analysis of the durations and frequencies of discrete behaviours. In this study, a T-pattern was defined as a reoccurring sequence of ≥2 behavioural event types 2 linked by a non-random critical period of time and occurring more often than expected by chance. This study aimed to identify differences in the behavioural distribution and organization of two forms of injurious pecking, head pecking (HP) and severe feather pecking (SFP), and non-damaging gentle feather pecking (GFP) in domestic turkeys using two analytical methods T-pattern analysis and a conventional assessment of behavioural frequencies and durations. Video observations of pecking behaviour were obtained from focal samples of domestic male turkeys between 5 and 15 weeks of age. Each focal sampling observation recorded all behaviours shown by a single turkey 120 s (s) before and after the turkey performed HP, GFP, or SFP (241 s total observation length per pecking event). Pecking type had no effect on the number of T-patterns and the frequency of T-pattern occurrences. However, both T-pattern detection and the conventional analysis showed turkeys in observations containing HP tended to be more active with shorter lying durations (H = 7.36, df = 2, P = 0.025), less frequent standing (H = 5.61, df = 2, P = 0.061), and less structured T-patterns (total T-pattern durations: H = 5.996, df = 2, P = 0.050, mean durations: H = 5.34, df = 2, P = 0.068) than turkeys engaged in GFP or SFP. The analyses also showed that turkeys that performed SFP tended to show more frequent GFP than turkeys that performed HP (H = 5.79, df = 2, P = 0.055). However, discrepancies in organization of feeding and foraging behaviour between the two analytical methods highlighted the susceptibility of both methods to behavioural variation between individuals when using small sample sizes. Future research should use T-pattern detection to evaluate age, sex, and environmental differences in the organization of the injurious pecking behaviour in domestic turkeys.