The potential introduction of SARS-CoV-2, the virus responsible for the COVID-19 pandemic, into North American bat populations is of interest to wildlife managers due to recent disease-mediated declines of several species. Populations of little brown bats (Myotis lucifugus) have collapsed due to white-nose syndrome (WNS), a disease caused by the introduction and spread of the fungal pathogen Pseudogymnoascus destructans (Pd). Throughout much of the United States and southern Canada, large colonies of the species routinely established diurnal roosts in anthropogenic structures, thereby creating the potential for direct human contact and cross-species disease transmission. Given recent declines and the potential for further disease impacts, we collected oral swabs from eight little brown bat maternity colonies to assess the presence and prevalence of SARS-CoV-2 by RT-qPCR analysis. Little brown bat colonies in Maryland (n = 1), New Hampshire (n = 1), New Jersey (n = 2), New York (n = 1), Rhode Island (n = 2), and Virginia (n = 1) were taken during May-August, 2022. From 235 assayed individuals, no bat tested positive for SARS-CoV-2. Our results indicate that little brown bats may not contract SARS-CoV-2 or that the virus persists at undetectable levels in populations of the Mid-Atlantic and Northeast during summer months. Nonetheless, continued monitoring and future work addressing other seasons may still be warranted to conclusively determine infection status.

Abandoned mines offer important roosting habitat for several species of bats throughout the western United States. Currently, abandoned mine reclamation programs are tasked with closing abandoned mines to ameliorate safety, health, and environmental hazards found in and around these sites. Without appropriate pre‐closure evaluations to determine use of mine workings prior to closure, bats that depend on abandoned mines may be negatively impacted. To mitigate impacts of abandoned mine reclamation on bats, surveyors typically conduct pre‐closure biological evaluations and recommend wildlife compatible closures (e.g., bat gates) for ecologically important sites. Due to hazardous conditions found in many abandoned mines, internal surveys cannot always be conducted, and external surveys are not reliable for determining underground habitat or inferring past, future, or potential use of mines by bats when they are absent during external surveys. The purpose of our study was to use internal mine surveys to examine relationships between abandoned mine use by bats and characteristics of the mine and landscape, including portal area and shape, number of portals, mine depth, elevation, proximity to water and land use type. We found that surface features including land use type, distance to water, and elevation were associated with bat use, as were several mine features including depth of workings and portal shape. To best conserve sensitive species of bats, it is essential that pre‐closure biological evaluations be as detailed as possible to enhance biological understanding of species' roosting associations and distribution throughout the landscape. Further information will best facilitate development of ecologically sound closure recommendations for abandoned mine openings.

Los murciélagos que hibernan suelen correr riesgo de sufrir perturbaciones humanas, tales como la pérdida de un hábitat adecuado debido al cambio climático o las modificaciones antropogénicas y la surgencia de enfermedades. El murciélago orejudo de Townsend (Corynorhinus townsendii) es una especie que se distribuye por todo el oeste de los Estados Unidos y que se encuentra bajo el estatus de conservación de “preocupación especial”. Durante el invierno, los individuos hibernan principalmente en cuevas, minas y otras estructuras similares a cavernas, muchas de las cuales están amenazadas. El objetivo de este estudio fue utilizar datos de microsatélites y mitocondriales para investigar la estructura genética de los hibernáculos de C. t. townsendii la subespecie más occidental de C. townsendii en el este de California y el oeste de Nevada. Descubrimos que ambos tipos de marcadores moleculares muestran una falta de estructura genética poblacional entre los hibernáculos occidentales, similar a los resultados de los estudios de colonias de maternidad en el área de estudio. No obstante, cuando comparamos los datos mitocondriales de nuestra área de estudio con las poblaciones secuenciadas en todo el rango de distribución geográfica de la subespecie, encontramos estructura poblacional. Además, hallamos haplotipos únicos en los hibernáculos muestreados, lo que sugiere cierta restricción de la variación genética geográfica, destacando la importancia de mantener y proteger los refugios en toda la región para promover la diversidad genética en C. t. townsendii. Estos resultados proporcionan datos de referencia sobresalientes que pueden ayudar a comprender cómo el cambio climático, la pérdida de hábitat y las enfermedades pueden afectar la salud genética de los pequeños mamíferos durante su hibernación.

White-nose syndrome, a disease caused by the fungal-pathogen Pseudogymnoascus destructans, has caused drastic reductions in populations of several North American hibernating species of bats including Myotis lucifugus (Little Brown Bat), Myotis septentrionalis (Northern Long-eared Bat), and Perimyotis subflavus (Tricolored Bat). Recent data indicate that populations of Little Brown Bats may be stabilizing and/or increasing in the northeastern region of the US, while others, such as Northern Long-eared Bats, continue to decline. Whether these trends extend to the mid-Atlantic region is currently unknown. To better understand population changes over time, habitat associations, and species dynamics, we developed models of relative activity from bat acoustic data collected on the National Park Service's Chesapeake and Ohio Canal National Historical Park along the Potomac River Corridor in western Maryland between 2016 and 2022. Consistent with pre-disease habitat associations, Little Brown Bats and Tricolored Bats exhibited a positive correlation with proximity to water bodies. Notably, we found Little Brown Bat and Tricolored Bat populations potentially were increasing, whereas Northern Long-eared Bats showed no correlation with examined habitat covariates and had low detection levels, trends consistent with broader declines throughout their range.