Recent climate changes have produced extreme climate events. This study focused on extreme snowfall and intended to discuss the vulnerability of temperate mammals against it through interspecies comparisons of spatial niches in northern Japan. We constructed niche models for seven non-hibernating species through wide-scaled snow tracking on skis, whose total survey length was 1144 km. We detected a low correlation (rs < 0.4) between most pairs of species niches, indicating that most species possessed different overwintering tactics. A morphological advantage in locomotion cost on snow did not always expand niche breadth. In contrast, a spatial niche could respond to (1) drastic landscape change by a diminishing understory due to snow, possibly leading to changes in predator-prey interactions, and (2) the mass of cold air, affecting thermoregulatory cost and food accessibility. When extraordinary snowfall occurred, the nonarboreal species with larger body sizes could niche shift, whereas the smaller-sized or semi-arboreal mammals did not. In addition, compared to omnivores, herbivores were prone to severe restriction of niche breadth due to a reduction in food accessibility under extreme climates. Dietary habits and body size could determine the redundancy of niche width, which may govern robustness/vulnerability to extreme snowfall events.

中文翻译：

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陆地哺乳动物面临极端降雪时的空间生态位差异：以东亚森林为例


最近的气候变化已经产生了极端气候事件。这项研究的重点是极端降雪，旨在通过日本北部空间生态位的种间比较来讨论温带哺乳动物对其的脆弱性。我们通过滑雪板大范围的雪地跟踪，构建了 7 个非冬眠物种的生态位模型，总测量长度为 1144 公里。我们发现大多数物种生态位对之间的相关性较低（rs < 0.4），这表明大多数物种拥有不同的越冬策略。雪上运动成本的形态优势并不总是扩大生态位宽度。相比之下，空间生态位可以响应（1）由于降雪导致林下植被减少而导致的剧烈景观变化，可能导致捕食者与猎物相互作用的变化，以及（2）冷空气质量，影响体温调节成本和食物可及性。当发生异常降雪时，体型较大的非树栖物种可能会发生生态位转移，而体型较小或半树栖哺乳动物却不会。此外，与杂食动物相比，食草动物由于极端气候下食物可及性的减少而容易受到生态位宽度的严重限制。饮食习惯和体型可以决定生态位宽度的冗余，这可能决定对极端降雪事件的鲁棒性/脆弱性。