Deer behavioural expression variation in relation to physiological context in a farming environment

Abstract

Context: Behavioural traits in farmed animals influence welfare and productivity. In New Zealand, red deer (Cervus elaphus) has undergone more than 35 years of domestication and selection, potentially altering behavioural expression. Aims: This study investigated how physiological contexts, namely, late lactation, mating, and early winter, influence individual behavioural variation in farmed red deer hinds, hypothesising that behaviour differs across contexts and over time. Methods: Eighty-seven red deer hinds were fitted with GPS and accelerometer collars during three physiological periods. Data were filtered for quality and processed using validated algorithms to estimate walking distance, foraging time, and energy expenditure. Key results: Twenty-six hinds with complete datasets across all periods were analysed. Behavioural metrics were statistically compared by using ANOVA and Tukey’s honestly significant difference tests. Significant differences were found in walking distance, foraging time, and energy use across contexts and individuals. Walking distance peaked during mating (4621 m/day), was intermediate in late lactation (4284 m/day), and lowest in early winter (3316 m/day). Foraging time was highest in late lactation (14.5 h/day) and lowest in early winter (12.3 h/day). Energy use was highest during lactation (62.3 kJ/kg LW.day). Individual variation (standard deviation and coefficient of variation) differed by context, with early winter showing lower absolute but higher relative variation in foraging time. Conclusions: Physiological context significantly influences behavioural expression and its variability. The reduced metabolic rate in winter is likely to limit behavioural plasticity, whereas lactation demands drive increased activity. Implications: Wearable technology was shown to be effective for monitoring behaviour, offering insights for improving welfare and productivity through context-aware management strategies