Forest proximity enhances bat activity in Midwestern agricultural fields: Implications for edge management and ecosystem services

Forest edges are known to support biodiversity and ecosystem function in agricultural landscapes, but their role in shaping bat activity across large-scale monocultures remains unclear. We investigated how proximity to forested edges influences insectivorous bat activity across phonic groups in Midwestern U.S. row crop systems, and whether these effects persist after controlling for insect abundance and abiotic conditions. Acoustic recordings and paired insect samples were collected from June to September in Indiana corn and soybean fields (n = 20 sites). Generalized linear mixed models revealed that bat activity was significantly higher near tree lines for all phonic groups, with low-frequency and Myotis phonic groups showing the strongest spatial associations. These patterns closely tracked insect abundance, suggesting that forest adjacent fields may offer enhanced foraging opportunities. Our results provide fine-scale, field-based evidence that retaining or restoring forest elements along crop boundaries can bolster bat presence and help sustain biodiversity and ecological function in simplified agroecosystems.