Environmental cues and individuality shape diel and seasonal antelope behaviour in African drylands

Large herbivores play a central role in dryland ecosystems, influencing vegetation dynamics, nutrient cycling, and trophic interactions. While they are adapted to cope with harsh climates, their persistence is increasingly threatened by anthropogenic pressures. However, the behavioural strategies they use to cope with these combined environmental challenges remain understudied. Using multi-year accelerometer data from springbok (Antidorcas marsupialis), greater kudu (Tragelaphus strepsiceros), and common eland (Taurotragus oryx) in northern Namibia, we examined diel and seasonal behaviour in relation to vegetation greenness (NDVI), temperature, lunar phase, and individual differences. While activity was mainly diurnal, nocturnal behaviour was closely linked to the lunar cycle: during moonlit nights, antelope, particularly springbok, increased feeding and walking while reducing rumination and resting. Seasonal patterns tracked plant phenology, with head-up feeding rising sharply during the woody flush at the onset of the green season, while head-down feeding followed grass growth but declined as the season progressed. Seasonal dynamics differed from studies in other regions, suggesting that prolonged dryness and mild winters favour energy conservation over compensatory feeding. Hierarchical partitioning showed that feeding behaviours were environmentally cued, driven by plant phenology and seasonality, whereas walking, rumination, and resting were shaped mainly by individuality. Ambient temperature added little explanatory power, indicating that long-term rhythms are governed more by vegetation cycles and photoperiod than by thermal conditions. Our findings reveal that external cues such as phenology and moonlight synchronise foraging across individuals, while intrinsic factors contribute most to the variation in walking, ruminating and resting, potentially buffering populations against environmental variability. Recognising the combined influence of environmental cues and individual variation is essential for predicting how dryland herbivores will respond to climate and land-use change.