Data from: Spatio-temporal and demographic variation in the diet of New Zealand lesser short-tailed bats (Mystacina tuberculata)

Variation in the diet of generalist insectivores can be affected by site-specific traits including weather, habitat, and season, as well as demographic traits like reproductive status and age. We used molecular methods to compare diets of three distinct New Zealand populations of lesser short-tailed bats, Mystacina tuberculata. Summer diets were compared between a southern cold-temperate (Eglinton) and a northern population (Puroera). Winter diets were compared between Pureora and a subtropical offshore island population (Hauturu). This also permitted seasonal diet comparisons within the Pureora population. Lepidoptera and Diptera accounted for > 80% of amplicons identified from faecal matter at each site/season. The proportion of orders represented within prey and the Simpson diversity index, differed between sites and seasons within the Pureora population. For the Pureora population, the Simpson diversity index was higher in summer than winter and was higher in Pureora compared to Eglinton. Summer Eglinton samples revealed that juvenile diets appeared to be more diverse than other demographic groups. Lactating females had the lowest dietary diversity during summer in Pureora. In Hauturu, we found a significant negative relationship between mean ambient temperature and prey richness. Our data suggest that M. tuberculata incorporate a narrower diversity of terrestrial insects than previously reported. This provides novel insights into foraging behaviour and ecological interactions within different habitats. Our study is the first from the southern hemisphere to use molecular techniques to examine spatio-temporal variation in the diet of a generalist insectivore that inhabits a contiguous range with several habitat types and climates.

广食性食虫动物（generalist insectivore）的饮食变异可受多种位点特异性特征（涵盖天气、栖息地与季节）以及繁殖状态、年龄等种群统计特征的影响。我们采用分子生物学手段，对新西兰境内3个不同种群的小短尾蝠（lesser short-tailed bat, Mystacina tuberculata）的饮食组成展开对比分析：分别对南部寒温带种群（埃格林顿/Eglinton）与北部种群（普奥罗拉/Puroera）的夏季饮食进行比较；同时以普奥罗拉种群为研究对象，对比其冬季饮食与亚热带离岸岛屿种群（豪图鲁/Hauturu）的冬季饮食，借此亦可开展普奥罗拉种群内部的季节饮食差异分析。各采样位点/季节的粪便样本扩增子（amplicon）中，鳞翅目（Lepidoptera）与双翅目（Diptera）昆虫占比均超过80%。猎物类群的组成占比与辛普森多样性指数（Simpson diversity index）在不同采样位点以及普奥罗拉种群内部的季节间均存在显著差异。就普奥罗拉种群而言，其夏季的辛普森多样性指数高于冬季，且较埃格林顿种群更高。夏季埃格林顿种群的样本显示，幼年个体的饮食多样性似乎高于其他种群统计组。普奥罗拉种群的泌乳雌性个体在夏季的饮食多样性最低。在豪图鲁种群中，我们发现平均环境温度与猎物类群丰富度之间存在显著负相关关系。我们的研究数据表明，Mystacina tuberculata所摄食的陆生昆虫类群多样性较既往报道更为狭窄。该研究为不同生境下的觅食行为与生态互作提供了全新的研究视角。本研究是南半球首个利用分子技术，针对栖息于包含多种栖息地与气候类型的连续分布区内的广食性食虫动物，开展其饮食时空变异分析的相关研究。