Pest suppression services of insectivorous bats in intensively managed arable land benefit from adjacent near-natural areas

Ecosystem services, in particular pest consumption, provided by insectivorous bats are an important but underappreciated economic benefit of biodiversity. In this study, we asked whether bat-mediated pest suppression services benefit from near-natural areas adjacent to farmland. We used high-throughput tracking and genetic sequencing to determine the habitat use and diet of 128 common noctule bats ( Nyctalus noctula ). Common noctule bats spent an average of 55 % of their foraging localisations over arable land, although arable land made up more than 95 % of the area within their activity range, thus bats avoided foraging over agricultural fields. In contrast, 14 % of foraging localisations were observed over water and wetlands, although these habitats made up only 0.5 % of the area, showing a strong preference. Consequently, the diet of bats consisted mainly of insects with aquatic larval stages, but also included many agricultural pest species. Of all insects consumed, 23 % were classified as pests (agricultural, silvicultural or nuisance), highlighting the ecological importance of noctule bats in both near-natural and human-altered ecosystems. Our data demonstrate that the pest consumption by bats on farmland benefit from adjacent near-natural areas where bats can find sufficient insects to meet their energy demands. These findings highlight the need to maintain a high degree of habitat heterogeneity for the conservation of bat species and their contribution to a sustainable agricultural practice. • Water bodies are critical foraging habitats in resource-poor landscapes. • We link tracking data of 128 common noctule bats from 3 study years with their diet. • Despite the habitats rarity, most consumed insects were from aquatic habitats. • Regardless of foraging habitat used, bats consumed pest species. • Nearly a quarter of the consumed insect species were pests.