Hopping with the seasons: Weather and landscape features affect seasonal and diurnal movement of mountain hares

Context. Although animals are well adapted to natural weather fluctuations and have different strategies to adjust their space use to environmental conditions, climate change may lead to more frequent and unpredictable extreme weather events. Objectives. We investigated how landscape composition and seasonally varying weather conditions affect mountain hare ( Lepus timidus ) movement behaviour in southeastern Norway. Methods. We estimated monthly range sizes and movement distances of 26 GPS-collared mountain hares (> 8000 ‘hare days’ and > 100,000 GPS locations) and investigated the effect of landscape variables, weather conditions (for movement distances only), season, and sex on ranging behaviour. Results. Overall home range sizes (95% KDE) ranged from 43 to 363 ha (mean estimate: 174 ha; 95% CI: 138–210 ha). Males used larger monthly ranges and moved further than females, especially during the breeding season, whereas hares generally moved shorter distances in fall. The effect of temperature on movement differed among seasons, suggesting that hares adjusted their movements to thermal conditions and seasonal energy demands. Wind, rainfall, and fresh snowfall had smaller and more variable effects, potentially related to energy conservation, shelter use, or anti-predator behaviour. Conclusions. Combined, our study shows that mountain hare movement behaviour is shaped by sex, season, landscape, and weather variables. This provides important information for this species, which is predicted to encounter increasing pressure and challenges in the future. Population-level consequences of hares will not only depend on changing weather conditions, but also on the availability of suitable food and sheltered microhabitats and on the hares’ capacity to adjust their behaviour.