The potential for bats to provide biodiversity-based ecosystem services in agriculture

Erin McHale and Kathleen Kerwin, Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, NJ, Brooke Maslo, Rutgers Cooperative Extension, Rutgers University, Rebecca Mau, Pathogen Microbiome Institute, Northern Arizona University, Flagstaff, AZ, Ryelan McDonough, Pathogen and Microbiome Instutute, Northern Arizona University, AZ, Jeff T. Foster, Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ

Background/Question/Methods
Research on the links between biodiversity and ecosystem function has demonstrated that biodiversity directly influences the delivery of multiple ecosystem services. These relationships are perhaps most evident in the context of global food security. Agricultural intensification is a key driver of biodiversity loss. Increasing food production requires simplification of landscape structure and homogenization of crop diversity to promote provisioning services, as well as an increased chemical input for insect pest suppression. Projected future global demands for food will require an increase in crop yields which will rely on ecosystem services, such as pollination and pest control. Recent studies have shown that the utilization of ecosystem services sustainably increases agricultural production. However, knowledge gaps exist at the scale of both individual species and dietary breadth. Insectivorous bats have long been suggested to provide substantial pest-regulation and thus may be a critical component of biodiversity-based ecosystem services. Yet, the biological and economic importance of bats to agriculture remains unquantified. In this study, we attempt to bridge this gap by quantifying the dietary breadth of the little brown bat (Myotis lucifugus) and the big brown bat (Eptesicus fuscus) We conducted a molecular analysis of guano collected from seven sites in New Jersey over a 26-week period in 2017. Using molecular techniques, we compared interspecific differences in diet and examined seasonal patterns in prey selection.
Results/Conclusions
Species richness of prey consumption varied significantly between bat species, with little brown bats and big brown bats eating an average of 27 and 18 species, respectively. We found that approximately 20% of prey species within the guano of these bats are classified as agricultural pests, 29 of which are classified as major pests. We also detected 11 vectors of human or zoonotic diseases, including five mosquito species. Interestingly, pest species made up a significantly greater proportion of big brown bat diets (30%) than little brown bats (1%). Big brown bats consumed few insect species during early sampling period and peaked toward the end of the sampling period. Little brown bats, however, consumed larger numbers of insect species in early portion of the sampling season, and peaked in mid-season. This study provides a promising insight into the role of bats in agricultural integrated pest management and lays the foundation for understanding their full potential as critical components of biodiversity-based ecosystem services.