Bats III

Contributed Paper

12:50PM Bat Foraging Habitat Use: Relationship with Forest and Landscape Conditions
Megan Gallagher
Summer bat habitat use in the Northeast has not been well studied and there has been no research on habitat use in relation to important forest features and management histories in the central Adirondack region. Since the emergence of white-nose syndrome (WNS), research has largely focused on winter bat ecology. However, studies on summer habitat use requirements are equally as important since this is when females are choosing suitable roost and foraging locations that will support them while they are raising young. The Adirondack region has a long history with forest alterations and various management regimes which may affect how bats are currently using these habitats. The objectives of this study are to 1) determine what bat species are present within the central Adirondacks, and 2) investigate habitat use of foraging bats on managed landscapes in relation to forest features. We used Sonobat detectors to survey bats from June through August 2017. We fit single season single species occupancy models for each species or species grouping: Myotis (M. lucifugus, M. sodalis, M. leibii, and M. septentrionalis), EPFU/LANO (Eptesicus fuscus and Lasionycteris noctivagans), LACI (Lasiurus cinereus), and LABO (Lasiurus borealis). We evaluated priori hypothesis by first evaluating factors affecting p and then evaluated habitat and landscape effects. The probability a site was occupied by foraging bats varied among species, although generally higher temperatures, lower humidity, less rain, and greater canopy openness resulted in higher p values for several bat species in the central Adirondacks. We will be using the same field methods for a second field season and will survey different locations to add to the overall sampling size. Results of this project will be directly applied to forest management practices incorporating bat conservation and timber production in the Northeast.
1:10PM Who, When, Where: Year-Round Bat Activity Patterns along the Mid-Atlantic Coast
Elaine L. Barr; Alexander Silvis; W. Mark Ford
In eastern North America, wind energy is a significant threat to bats. However, most research has been conducted along the Appalachian Mountains where fatalities are easily documented. With high wind resources, coastal areas in the mid-Atlantic are ripe for energy development and impacts to migratory species such as the eastern red bat (Lasiurus borealis) and hoary bat (Lasiurus cinereus) are unknown. Additionally, the threatened northern long-eared bat (Myotis septentrionalis) was recently documented over-wintering in mid-Atlantic Coastal Plain forests in southeastern Virginia and northeastern North Carolina. To answer questions about drivers of coastal bat activity patterns prior to wind energy development and to examine the potential for over-wintering northern long-eared bats, we used acoustic detectors to continuously monitor bat activity year-round on NASA’s Wallops Flight Facility on Virginia’s Eastern Shore. Although activity was greatest during the summer for all of the seven species we documented, bats were active year-round. Bat activity was related to temperature, wind speed, and precipitation. The importance of these predictors varied by season, with temperature more important in the winter and spring and wind speed in the fall. Hoary bat activity was greater in the winter than the fall or spring, indicating that the area may be a significant over-wintering site for this species which is particularly susceptible to wind energy impacts. Surprisingly, evening bats (Nycticeius humeralis), were the most commonly recorded species, despite being at their northernmost distributional limit. We did not observe presence of northern long-eared bats in the winter, suggesting aberrant costal non-hibernacula over-wintering does not occur as far north as the Delmarva Peninsula in Virginia. Our work provides greater understanding of the drivers of coastal bat activity as well as seasonal distributions that can inform managers tasked with managing potential future wind-energy development in the region.
1:30PM Road Transect Acoustic Monitoring Reveals Spatial and Temporal Patterns of Bat Activity in Iowa
Julie A. Blanchong; Heather Sanders; Jake Rector; Jacob Figge; Adam Janke
White-nose syndrome (WNS) caused by the fungus Pseudogymnoascus destructans is responsible for the deaths of millions of bats in North America. The presence of WNS in Iowa was confirmed in 2015. To better understand bat abundance and distribution in Iowa and the potential impacts of WNS we conducted acoustic surveys along 19 road transects in May-August 2013-2016 in eastern, central, and southern Iowa. Bat echolocation calls were recorded using Anabat SD2 detectors and were GPS referenced. Echolocation data were analyzed to identify bat calls to frequency group (LOW, MID, Myotis spp) and species. We tested for spatial and temporal relationships with total bat call detection, detection for each frequency group, and detection for each species. We also tested for relationships between landscape features along transects and the probability of bat detection. Significantly more bat calls were detected in eastern Iowa than in central and southern Iowa. More MID frequency bats and Myotis spp bats were detected in eastern Iowa than elsewhere. Consistent with frequency group findings, we detected more Lasiurus borealis (MID), Perimyotis subflavus (MID), and Myotis lucifugus (Myotis spp) bats in eastern Iowa. There was also a decrease in Myotis spp detections over time. Along transects, the probability of detecting a bat was positively related to amount of forest and negatively related to distance from water. Higher total bat detections and detections of MID and Myotis spp bats in eastern Iowa may be related to the larger amount of forest habitat compared to central and southern Iowa. The decline in detection of Myotis spp over time may be associated with impacts of WNS. As WNS prevalence and other challenges to bats such as wind energy development increase across Iowa, continued monitoring will be important to document impacts to bat populations and develop appropriate management and mitigation actions.
1:50PM Wns-Induced Temporal and Spatial Changes in Little Brown Activity
Tomas Nocera; William W. Ford; Alex Silvis; Chris A. Dobony
How bat distribution and habitat associations have changed at the local to sub-landscape scale has received little attention to date despite being a critical information need for managers in the post White-nose syndrome (WNS) environment. To better understand the spatial nature of population decline, we modelled, both activity patterns and occupancy from acoustic surveys for the little brown bat (Myotis lucifugus) on Fort Drum Army Installation in New York over 15 summers (2003-2017) that span the pre-WNS, WNS advent (2008) and post-WNS periods, using a set of generalized linear mixed models and geospatial analysis. Our top model indicated significant differences between years (p ≤ 0.05) with significant declines in activity post-WNS. Little brown bat activity was most associated with woody wetland habitats over the entire study duration, however, the spatial patterns of high activity areas were variable over years, with the areal extent of these high activity areas decreasing post-WNS. Our best supported occupancy model varied by year, however, the model where occupancy estimates were constant with regard to environmental factors [Ψ(.)] were either competing (models within 2 ΔAIC units) or was the best supported model. There was high disagreement between our relative activity models and predictions compared to our occupancy models, suggesting that spatial scale impacts model accuracy. Our results indicate that continued acoustic monitoring of bat species, such as the little brown bat in the Northeast, to assess ongoing temporal and spatial changes, habitat associations, and as a guide to direct future mist-netting should rely more on relative activity as the metric of choice.
2:10PM Habitat Use and Seasonal Behavior of Bats on Us Army Land in Interior Alaska
Kim Jochum; Garrett Savory; Jacob Pelham; Justin Smith
The little brown bat (Myotis lucifugus) is the only known bat species to occur in interior Alaska. US Army Garrison Fort Wainwright is interested in mitigating possible impacts of military training to the little brown bat due to the possible listing of this species under the Endangered Species Act in the near future. Our objectives were to determine seasonal and spatial use of habitats on Fort Wainwright by bats, and to identify roost sites. We investigated behavior and habitat associations of bats on Fort Wainwright land (~ 1.6 million acres) via active and passive monitoring methods on a spatial and temporal scale between 2014 and 2018. Bioacoustic recorders were used to detect bat presence across hundreds of sites during April and October in all years. In part of the study area, we deployed detectors bi-weekly in a spatially-balanced sampling design to analyze habitat and environmental factors impacting bat occupancy (2016-2017). We detected bats from early April through October with the highest detection rate occurring in August and the lowest detection rates in June and October. Preliminary occupancy results reveal distance to water and old growth mixed forest to be important resources. In 2017 we added bat netting and telemetry to our study efforts to understand numbers, species, and status of bats present. From telemetry, we identified day roosts, transitional roosts, and potential maternity roosts at rocky cliff faces. We report final results of temporal and spatial detections, final results of the occupancy analysis, and key results of the telemetry study still in progress. Understanding seasonal behavior of bats and habitat use, specifically roost site identification, is necessary to develop meaningful bat management conservation plans for interior Alaska.


Contributed Paper
Location: Huntington Convention Center of Cleveland Date: October 11, 2018 Time: 12:50 pm - 2:30 pm