Microbat activity in vegetable crops relative to insect, landscape, and abiotic influences

Context As natural landscapes continue to be modified, there is growing evidence that some wildlife can persist in disturbed areas that have adequate resources. Invertebrates synonymous with crop farming may be one such reliable and attractive resource to extant insectivorous wildlife, such as microbats. Objectives To build on existing knowledge bases of microbats using complex agroecosystems globally, we evaluated if microbats were also active across the less researched, relatively open vegetable crops. Methods We assessed three vegetable farms in southeast Queensland, Australia, testing relationships between the number of microbat call sequences and microbat richness to landscape, season, and moon phase dynamics. We also tested relationships between crop invertebrate abundances and richness, as collected on sticky traps, to landscape dynamics and microbat call sequences. Microbat scats from the area were assessed to identify the invertebrates consumed using metabarcoding. Results We found that the open, mixed vegetable crop farm configuration supported the activity of 55% of the microbat species known to occupy the region (17/31). Microbat activity was continually observed across both the typically high (autumn) and low (winter) activity periods, though was higher in autumn. Microbat activity was also continually observed during waning gibbous and waxing gibbous to new moon phases, though was higher during waning gibbous. Of the landscape features, creek edges supported the highest microbat species richness and call activity. Invertebrate surveys confirmed high abundance and richness across the farm landscape area. Metabarcoding analysis revealed that nearly one-third of the invertebrate species identified in microbat scats were also present on farm sticky traps, with the most frequently consumed orders matching those most abundant on the farms. Conclusions We suggest that targeted wildlife-friendly management could enhance resource use of vegetable crops to help conserve microbats and benefit crops.