Individual identity and environmental conditions explain different aspects of sleep behaviour in wild boar

Abstract

Sleep is a fundamental behaviour as it serves vital physiological functions, yet how the sleep of wild animals is constrained by environmental conditions is poorly understood. Using non-invasive multi-sensor high-resolution biologgers and a robust classification approach, we quantified multiple dimensions of sleep in wild boar (Sus scrofa), a nocturnally active mammal, monitored for up to a full annual cycle. In support of the hypothesis that environmental conditions determining thermoregulatory challenges regulate sleep, we show that on warmer, longer, and more humid days sleep quality and quantity are reduced, whilst greater snow cover and rainfall promote sleep quality. Importantly, our study reveals large inter-and intra-individual variation in sleep durations, suggestive of pace-of-life syndromes. Given the major role that sleep plays in health, our results suggest that global warming and the associated increase in extreme climatic events are likely to negatively impact sleep, and consequently health in wildlife, particularly in nocturnal animals.

Hogs sleep like logs: wild boars reduce the risk of anthropic disturbance by adjusting where they rest

“…Besides, non-targeted disturbances are often short-lived, and will only reduce resting time marginally. Additionally, in our study, the wild boars remained inactive for 14 hours per day on average, which was longer than the total sleep time previously recorded in domestic pigs (7.8 hours) (Campbell & Tobler 1984) and in free-ranging wild boar (10.6 hours) (Mortlock et al 2022). This suggests that disturbances that do not entice a relocation likely have only a minor implication for fitness.…”

Hogs sleep like logs: Wild boars reduce the risk of anthropic disturbance by adjusting where they rest

“…Besides, non‐targeted disturbances are often short‐lived, and will only reduce resting time marginally. Additionally, in our study, the wild boars remained inactive for 14 h/day on average, which was longer than the total sleep time previously recorded in domestic pigs (7.8 h; Campbell & Tobler, 1984 ) and in free‐ranging wild boars (10.6 h; Mortlock et al, 2022 ). This suggests that the wild boars were unlikely to suffer harmful reductions in resting time due to anthropic disturbances.…”

“…&Tobler, 1984) and in free-ranging wild boars (10.6 h;Mortlock et al, 2022). This suggests that the wild boars were unlikely to suffer harmful reductions in resting time due to anthropic disturbances.…”