Northern Long-Eared Bat (Myotis septentrionalis) Day-Roost Loss in the Central Appalachian Mountains following Prescribed Burning

W Mark Ford,Joshua B Johnson,Melissa Thomas-Van Gundy,Nikolaos D Hasanagas

doi:10.1155/2021/5512044

Abstract

Before the arrival of white-nose syndrome in North America, the northern long-eared bat (Myotis septentrionalis) was a common cavity-roosting bat species in central Appalachian hardwood forests. Two successive prescribed burns on the Fernow Experimental Forest, West Virginia, in 2008 and 2009, were shown to positively affect maternity colony day-roost availability and condition in the near-term. However, whether immediate benefits were temporary and if burned forests actually experienced an accelerated loss of trees and snags possibly suitable for bats more than background loss in unburned forests became an important question following the species’ threatened designation. In 2016, we revisited 81 of 113 northern long-eared bat maternity colony day-roosts initially discovered in 2007–2009 with the objective of ascertaining if these trees and snags were still standing and thus potentially “available” for bat use. Initial tree or snag stage condition class and original year of discovery were contributory factors determining availability by 2016, whereas exposure to prescribed fire and tree/snag species decay resistance were not. Because forest managers may consider using habitat enhancement to improve northern long-eared bat survival, reproduction, and juvenile recruitment and must also protect documented day-roosts during forestry operations, we conclude that initial positive benefits from prescribed burning did not come at the expense of subsequent day-roost loss greater than background rates in these forests at least for the duration we examined.

Highlights

Conservation of day-roosts is a central management tenet for many bat species
We examined data for northern long-eared bat day-roosts that were originally collected by [5, 8] from the Fernow Experimental Forest (FEF) in northeastern West Virginia (39°03′15′′N 79°41′15′′W). e FEF is a 1,900 ha experimental forest managed by the U.S Forest Service, Northern Research Station, located in the unglaciated Allegheny Plateau portion of the central Appalachians
To assess the effect of being subjected to prescribed fire or unburned (FIRE), initial tree or snag condition class (STAGE: 1–7) [25], surrogate decay resistance rank from tree species specific gravity values collected at the FEF (RANK) [26], diameter at breast height (DBH), and year of initial discovery (YEAR: 2007–2009), we modeled the outcome of day-roosts remaining standing and presumably available versus fallen

Summary

Introduction

Conservation of day-roosts is a central management tenet for many bat species. In much of eastern North America, the heavily forested central and southern Appalachian Mountains, lack of forests and/or trees and snags is not a limiting factor per se as much as forest stand structure that provides optimal condition and spatial configuration of suitable roosts. Endangered Indiana bat (Myotis sodalis) summer maternity colonies often require recently fire or flood-disturbed older-age stands containing trees and snags with exfoliating bark and high solar exposure as their ideal roost conditions are ephemeral and transitory [1,2,3,4]. For day-roost conditions, burning improves, at least temporarily, conditions for Indiana bats and the threatened northern long-eared bats (Myotis septentrionalis) [5, 8]. Female northern long-eared bat dayroosts are in cavities of live trees or standing snags across a wide variation in bole size and solar exposure [9]. Some northern long-eared bat day-roosts are lost from collapse or combustion during a prescribed burn [8], repeated fires can accelerate the processes of both cavity

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Conclusion