The diet of Myotis lucifugus across Canada: assessing foraging quality and diet variability

Variation in prey resources influences the diet and behaviour of predators. When prey become limiting, predators may travel farther to find preferred food or adjust to existing local resources. When predators are habitat limited, local resource abundance impacts foraging success. We analysed the diet of Myotis lucifugus (little brown bats) from Nova Scotia (eastern Canada) to the Northwest Territories (north-western Canada). This distribution includes extremes of season length and temperature and encompasses colonies on rural monoculture farms, and in urban and unmodified areas. We recognized nearly 600 distinct species of prey, of which ≈30% could be identified using reference sequence libraries. We found a higher than expected use of lepidopterans, which comprised a range of dietary richness from ≈35% early in the summer to ≈55% by late summer. Diptera were the second largest prey group consumed, representing ≈45% of dietary diversity early in the summer. We observed extreme local die...

猎物资源的丰度变化会影响捕食者的食性与行为。当猎物匮乏时，捕食者可能会跋涉更远以寻觅偏好食物，或是转而利用当地现有的可获取资源；若捕食者受到栖息地限制，则当地资源丰度将直接影响其觅食成功率。本研究分析了分布于加拿大东部新斯科舍省至加拿大西北部西北地区的小棕蝠（Myotis lucifugus）的食性，该采样覆盖区间涵盖了季节长度与温度的极端梯度，同时包含了农村单一种植农场、城市区域以及未受干扰的原生区域中的蝙蝠栖息群。研究共鉴定出近600种不同的猎物类群，其中约30%可通过参考序列文库完成物种鉴定。研究发现捕食者对鳞翅目（Lepidoptera）的取食占比高于预期：其在食性丰富度中的占比从夏季初期的约35%，升至夏季末期的约55%。双翅目（Diptera）是第二大被捕食猎物类群，在夏季初期的食性多样性中占比约为45%。本研究观测到极端的局域性……