Internal cavity characteristics of northern long-eared bat (<I>Myotis septentrionalis</I>) maternity day-roosts

Abstract

We report characteristics of seven tree cavities used as day-roosts by female northern long-eared bats (Myotis septentrionalis) during the maternity season in a deciduous forest in north-central Kentucky. Understanding the characteristics of cavities selected by bats will help us better understand the ecology of cavity roosting bats and the tree species and condition necessary for providing day-roost habitat. Cavity openings were created by either fungal decay or primary excavators. Length and volume of cavities were positively related to number of entrances. Mean area of entrances was positively related to the proportion of entrances created by primary excavators. The use of trade, fi rm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture or the Forest Service of any product or service to the exclusion of others that may be suitable. Quality Assurance This publication conforms to the Northern Research Station's Quality Assurance Implementation Plan which requires technical and policy review for all scientifi c publications produced or funded by the Station. The process included a blind technical review by at least two reviewers, who were selected by the Assistant Director for Research and unknown to the author. This review policy promotes the Forest Service guiding principles of using the best scientifi c knowledge, striving for quality and excellence, maintaining high ethical and professional standards, and being responsible and accountable for what we do. Cover Photo A white oak (Quercus alba) snag provides roosting opportunities for female northern longeared bats on the Fort Knox Military Reservation, Kentucky, USA. Photo by Alexander Silvis, Virginia Tech, used with permission.

Tree roosts of northern long‐eared bats following white‐nose syndrome

“…In locations where forests were actively managed with timber harvesting, northern long‐eared bats demonstrated preferential selection for roosts in only a few tree species (Menzel et al , Ford et al , Johnson et al , Silvis et al ), especially sassafras and black locust ( Robinia pseudoacacia ). Although an explanation for the difference is not immediately apparent, northern long‐eared bats do use cavities in the boles of dead and dying trees for roosting (Silvis et al ) and tree species possessing these features may be less available to bats in actively managed forests. Tree species such as sassafras and black locust have no commercial timber value and are often left behind in uncut habitats peripheral to stands targeted for harvesting.…”

“…Data from other roosting studies of northern long‐eared bats post‐WNS in Tennessee (Lereculeur ) and Indiana, USA (Badin ), also show small average exit counts. We hypothesize that reduced numbers of bats within roosts could lead to disruptions in social networks (Johnson et al , Silvis et al , ) and alterations to the internal thermal environment of roosts of these bats (Willis and Brigham , Roby et al , Johnson and Lacki ). Both scenarios could affect future rates of summer survival and reproductive success.…”

“…Within rows, means without common letters are different (P < 0.05). bats do use cavities in the boles of dead and dying trees for roosting (Silvis et al 2015b) and tree species possessing these features may be less available to bats in actively managed forests. Tree species such as sassafras and black locust have no commercial timber value and are often left behind in uncut habitats peripheral to stands targeted for harvesting.…”

Northern Long-Eared Bat Day-Roosting and Prescribed Fire in the Central Appalachians, USA

“…Transition of red maple snags into late condition class 6 or 7 with a clean bole happens rapidly (Johnson et al 2010), and in the absence of an accessible cavity, the stem is not a usable day-roost once remaining bark is gone unless a cavity is pres- ent. Live red maple that is fire weakened should be more susceptible to cavity formation from fungal pathogens, insect infestation, and the actions of excavators (Silvis et al 2015b). Some aspects of day-roost ecology did differ between the burned compartment and unburned stands.…”

Shifts in Assemblage of Foraging Bats at Mammoth Cave National Park following Arrival of White-nose Syndrome

“…Much of the research completed on roosting preferences of the Northern Long-eared Myotis during summer suggests potential overlap in preferences for roosting sites with that of Evening Bats. Female Northern Long-eared Myotis commonly roost under exfoliating bark or in cavities and crevices of dead and live trees (Broders and Forbes 2004, Carter and Feldhamer 2005, Lacki et al 2009, Silvis et al 2015, Timpone et al 2010. This scenario, though, is complicated by evidence for expansion of the geographic distribution of the Evening Bat along the northern limits of its range, which may be caused by climate change (Auteri et al 2016).…”