Geology topics

Nicholas J. Kalen

Publications and source records attributed to Nicholas J. Kalen.

3 recordsLinked to original sources

USGS2024

Seasonal activity patterns of northern long-eared bats on the coastal Mid-Atlantic

Conservation of bats declining from white-nose syndrome (WNS) impacts requires an understanding of both temporal and landscape-level habitat relationships. Traditionally, much of the research on bat ecology has focused on behavior of summer maternity colonies within species’ distribution cores, including that of the endangered northern long-eared bat ( Myotis septentrionalis ). To further our knowledge of this species, we evaluated multi-season activity patterns in eastern North Carolina and Virginia, including areas where populations were recently discovered. We used passive acoustic monitoring to assess relative and probable activity of northern long-eared bats from October 2016 to August 2021. Northern long-eared bat relative activity was greatest in areas containing greater proportions of woody wetlands and upland pine-dominated evergreen forests. However, the likelihood of recording northern long-eared bats was associated with smaller proportions of woody wetlands and open water resources. Furthermore, we observed a higher probability of recording northern long-eared bats during non-winter seasons. Probable activity was greatest at temperatures between 10 and 25 C, potentially highlighting an optimal thermoneutral zone for the species regionally. Relative activity of northern long-eared bats on the Coastal Plain of Virginia and North Carolina was primarily driven by cover features, whereas probable activity was driven by a combination of cover features, seasonality, and temperature. Therefore, acoustical surveys for this species may be most effective when targeting woody wetlands adjacent to upland forests, particularly upland pine-dominated evergreen stands, during moderate temperatures of non-winter seasons (1 April–15 November). Moreover, conservation of a diverse mosaic of woody wetlands juxtaposed by upland forests may promote both roosting and overwintering habitat, thereby enhancing overwintering survival, maternity colony establishment, and ultimately, successful reproduction of northern long-eared bats.

North Carolina, Virginia↗

USGS2022

Northern long-eared bats in the central Appalachians following white-nose syndrome: Failed maternity colonies?

Northern long-eared bat ( Myotis septentrionalis ) populations have experienced severe declines in eastern North America from white-nose syndrome (WNS), yet potential secondary effects on maternity roosting and recruitment remain largely unknown. We documented female day- roosting at two locations in the central Appalachians of Virginia, Back Creek Mountain (BCM) and Rapidan Camp (RC), during 2015 and 2016, ap- proximately six years after the regional onset of WNS. We compared roost characteristics with available trees and roosts recorded prior to WNS at the Fernow Experimental Forest (FEF), West Virginia, in 2007 and 2008. Roosts at BCM were smaller than pre-WNS roosts but were otherwise similar in terms of stand condition and species use, though bats selected for red maple ( Acer rubrum ) at BCM rather than black locust ( Robinia pseudoacacia ) as at FEF. At RC, bats roosted almost exclusively in large eastern hemlock ( Tsuga canadensis ) snags (dbh x ¯ = 50.13 cm, SD = 23.1) with high solar exposure that had been killed by the hemlock woolly adelgid ( Adelges tsugae ). The two observed strategies, selection of smaller, midstory trees at BCM and of dominant, exposed roosts at RC, correspond with pre-WNS observations of female northern long-eared bat roost use at similar sites. However, our re- sults suggest reliance on smaller roosts and canopy-dominant positions that better accommodate solitary individuals and small groups associated with smaller post-WNS colonies in terms of space and thermoregulatory benefits. Despite some observations of pregnant and lactating individuals, all three post-WNS colonies vacated roost networks in early June, and we observed no juveniles. Potential colony failure at BCM and RC is consistent with pre- dicted secondary physiological effects from WNS-induced population collapses, suggesting, if recruitment failed, northern long-eared bats may already be functionally extirpated in portions of the central Appalachians.

Virginia, West Virginia↗

USGS2021

Post-white-nose syndrome passive acoustic sampling effort for determining bat species occupancy within the mid-Atlantic region

We assessed the sampling effort requirements for detecting the presence of extant bat species following the impact of white-nose syndrome in the mid-Atlantic region of the United States. We acoustically sampled 27,796 nights across 846 sites between 15 May and 15 August 2016–2018 within the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia. We developed simulations to determine the number of sites required to document bat species when each site was sampled different numbers of nights. We examined these simulations with respect to land cover, physiographic region, and time period. We generally found that sampling a greater number of sample sites within a survey area increased detection more than increasing the number of nights at individual sampling sites. The sampling effort required to detect a given bat species varied by species, as well as land-cover type and physiographic region. Our results suggest that land managers and researchers should use caution in using protocols developed with other objectives, e.g., the U.S. Fish and Wildlife Service endangered and threatened bat species and the North American Bat monitoring programs’ methods are designed relative to their specific needs. Unfortunately, neither protocol may be adequate for accurately detecting bat communities within all mid-Atlantic areas.

Maryland, Pennsylvania, Virginia, West Virginia↗