Data from: Camera traps reveal seasonal variation in activity and occupancy of the Alpine mountain hare (Lepus timidus varronis)

Mountain hare is a cold-adapted species threatened by climate change, but
despite its emblematic nature, our understanding of the causes of
population decline remains limited. Camera traps are increasingly used in
ecology as a tool for monitoring animal populations at large spatial and
temporal scales. In mountain environments where field work is constrained
by difficult access and harsh conditions, camera traps constitute a
promising tool for surveying rare and elusive species such as the mountain
hare. Our study explored the use of camera traps as a tool for studying
seasonal habitat occupancy and daily activity patterns of the mountain
hare, in order to carry out long-term monitoring of populations. We
installed 46 camera traps along elevation gradients in the Mont-Blanc
massif (France) from January 2018 to June 2022. We measured habitat
variables at each camera trap site in order to define vegetation
composition and habitat structure. We performed multi-season and
single-season occupancy models to respectively describe habitat occupancy
of the mountain hare throughout the year and identify the environmental
variables influencing mountain hare presence during the breeding season.
Mountain hares occupy coniferous forest in winter, and then switch to
mixed areas of shrubland and grassland above treeline in spring and the
beginning of summer. In spring, occupancy probability of the mountain hare
increases with relative cover of mixed low shrub and herbaceous layer
(i.e. the 10-40 cm vegetation layer), suggesting a link to food resources
and protection from predation. Our results also confirm the nocturnal and
crepuscular activity of the mountain hare during the breeding season, and
strictly nocturnal activity in winter. Our results demonstrate the
efficiency of camera traps as tools for monitoring mountain hare habitat
occupancy in mountain environments and underline the importance of diverse
habitat mosaics for the preservation of the species.

雪兔（mountain hare）是一类适应寒冷环境的物种，正遭受气候变化的威胁；尽管其作为标志性物种具有重要地位，但学界对其种群下降的成因仍认知有限。相机陷阱（camera trap）作为可在大空间、时间尺度上监测动物种群的工具，在生态学研究中的应用愈发广泛。在山地环境中，野外作业受限于通行困难与严苛的自然条件，相机陷阱便成为监测雪兔这类珍稀隐匿物种的极具潜力的手段。本研究旨在开展雪兔种群的长期监测，探索利用相机陷阱研究雪兔季节性生境占用与日活动节律的可行性。2018年1月至2022年6月期间，研究团队在法国勃朗峰地块（Mont-Blanc massif）沿海拔梯度布设了46台相机陷阱。我们对每处相机陷阱点位测定生境变量，以明确植被组成与生境结构特征。我们分别构建了多季占用模型（multi-season occupancy model）与单季占用模型（single-season occupancy model）：前者用于描述雪兔全年的生境占用动态，后者用于识别繁殖季影响雪兔出现的环境变量。结果显示，雪兔冬季栖息于针叶林，春季与夏初则迁至林线（treeline）以上的灌丛-草地混合区域。春季时，雪兔的生境占用概率随低矮灌丛与草本层（即10~40 cm植被层）的相对盖度升高而增加，这表明其生境选择与食物资源获取及躲避捕食风险存在关联。研究结果同时证实，雪兔在繁殖季为夜行性与晨昏性活动，冬季则完全为夜行性活动。本研究结果证明，相机陷阱可有效用于山地环境下雪兔生境占用的监测工作，并强调了多样化生境镶嵌体对该物种种群保护的重要意义。