Availability of invertebrate prey for micro-carnivores

The lesser hairy-footed dunnart (Sminthopsis youngsoni, Dasyuridae) is a generalist marsupial insectivore in arid Australia, but consumes wolf spiders (Lycosa spp., Lycosidae) disproportionately often relative to their availability. This project tested the hypothesis that this disproportionate predation is a product of frequent encounter rates between the interactants due to high overlap in their diets and use of space and time. This data set focuses on the dietary aspect. Specifically, invertebrate pitfall trapping was employed to quantify food availability and selectivity for both wolf spiders and S.youngsoni. Pitfall traps were deployed along trails left by tracked individuals, as well as control trails, of both species groups in the north-western Simpson Desert, Queensland. In total, invertebrate pitfall traps were deployed along 11 S.youngsoni and 8 lycosa trails in October 2016. Invertebrates were identified to the level of "Order", except for spiders (Order: Arachnida) and bees, wasps and ants (Order: Hymenoptera) which were identified to the "Family" level using identification keys and were also counted and grouped into seven size classes. This data was used for the following analyses: [1] a two-way analysis of variance (ANOVA) to test whether total numbers of arthropods differed between trail type and species, [2] non-metric multidimensional scaling (NMDS) and [3] permutational analysis of variance (PERMANOVA) to test whether assemblages of arthropod prey and prey sizes differed between the two trail types for each species and between each species.

小毛足狭足袋鼩（Sminthopsis youngsoni，袋鼬科（Dasyuridae））是澳大利亚干旱地区的广食性有袋类食虫动物，但相较于狼蛛（Lycosa属，狼蛛科（Lycosidae））的环境可获得性，该物种对狼蛛的捕食频率显著偏高。本研究旨在验证如下假说：这种选择性捕食现象源于捕食者与猎物双方的食性、空间利用与活动时间均存在高度重叠，进而导致二者间的遭遇频次较高。本数据集聚焦于食性相关研究内容，具体而言，研究采用无脊椎动物陷捕器诱捕法，量化狼蛛与小毛足狭足袋鼩的食物可获得性及其取食选择性。研究区域位于昆士兰州辛普森沙漠西北部，陷捕器布设于两类物种类群的追踪活动路径以及对照路径沿线。2016年10月，研究人员共在11条小毛足狭足袋鼩活动路径与8条狼蛛活动路径沿线布设了无脊椎动物陷捕器。所有无脊椎动物均鉴定至目级阶元，但蜘蛛（蛛形纲（Arachnida））以及蜂类、胡蜂与蚁类（膜翅目（Hymenoptera））除外：上述类群借助分类检索表鉴定至科级阶元，同时统计其个体数量并划分为七个体型等级。本数据集用于以下三类分析：[1] 双因素方差分析（two-way analysis of variance, ANOVA），以检验不同路径类型与物种间的节肢动物总数量是否存在显著差异；[2] 非度量多维标度（non-metric multidimensional scaling, NMDS）；[3] 置换多元方差分析（permutational analysis of variance, PERMANOVA），用以检验两类物种在各自的两种路径类型间，以及不同物种间的节肢动物猎物类群组成与猎物体型大小是否存在差异。