Endangered Myotis bats forage in regeneration openings in a managed forest

Abstract

Bat populations face numerous threats, including the loss of forests in which they roost and forage. Present-day forests are commonly managed for timber harvesting, recreation, and wildlife. Understanding bat responses to forest management is crucial for balancing the conservation of endangered bats and forest restoration. We used radio telemetry to study nocturnal movements and habitat selection patterns of female and juvenile bats of two forest-dependent, federally listed bat species in an oak-dominated managed forest. We estimated foraging space use and assessed habitat selection for 33 northern long-eared bats (Myotis septentrionalis) and 25 Indiana bats (Myotis sodalis) from May to August 2014–2017 in south-central Indiana, USA. Myotis septentrionalis space use averaged 176 ha and bats selected water, historic thinning, and patch cuts (≤4 ha) over other habitats, with all but one bat avoiding larger openings (≥4-ha clearcuts). Myotis sodalis space use averaged 343 ha and bats selected 4-ha patch cuts, historic openings, and historic thinning over other habitats. In contrast to M. septentrionalis, one-third of the M. sodalis foraged over larger clearcuts, while two-thirds foraged over smaller openings and thinnings. We showed that bats were attracted to small regeneration harvests of varying structural ages. Forests maintained for a mix of mature stands, thinned stands, shelterwoods, small regenerative cuts (<7 ha), and small water sources should provide suitable foraging habitat for these endangered Myotis species, while also promoting forest regeneration.