Bat Habitat Use in White Mountain National Forest

Biological Conservation, 2005

The Journal of Wildlife Management, 1999

Recent studies have suggested that old-growth forests may be important habitat for some species of bats, but the proximate factors related to greater bat activit). in older forests are not well understood. To assess relative habitat use by bats, we used ultrasonic detectors and mist nets to sample bat activities among old-growth white pine (Pinus strobus) mixed woods, mature white pine mixed woods, boreal-type mixed woods, and selectively logged white pine mixed woods in central Ontario. We quantified 15 stn~ctural characteristics in the 21 stands sampled for bat activity. Detection rates of bfyotis species. silver-haired bats (Lasionycteris nocituagans), and hoary bats (Lasiurus cinereus) were 2.7-14.0 times greater in old-growth white pine mixedwood stands than in other stand types (P.s< 0.05).Multivariate habitat models suggested that, between logged and uncut stands, the availabilit). of potential roost sites may be an important determinant of bat activity for 3fyotis species and silver-haired bats. Among uncut stands, our habitat models suggested that snag availability was not an important \variable affecting habitat selection by bats. Rather, bat detection rates in uncut forests were correlated with canopy and subcanopy structure. Little brown bats (Myotis luci&ugugu.s) and northern longeared bats (M. septentrionalis) may spatially separate for feeding. To maintain habitat for bats, forest managers should implement timber harvest strategies that retain remnant old-growth white pine stands in the landscape, preserve snags and large live trees in selectively logged forests, and promote regeneration of second-growth white pine stands to old age rather than truncating age classes at younger ages.

2006

We studied the summer roosting ecology of female northern long-eared bats in the White Mountain National Forest of New Hampshire, and examined the importance of snag and stand characteristics at bat roosting sites. Radio-transmitters were used to track  northern long-eared bats to  roost trees;  (%) were in snags. Roosts were in  Fagus grandifolia,  Acer saccharum,  Betula alleghaniensis,  Acer rubrum, and  other species. Roost snags were larger in diameter (mean =  cm; p = .), taller (mean = . m; p &lt; .), had more bark remaining (mean = %; p = .), and were less decayed than random samples of snags in the surrounding area. Characteristics of the surrounding stand were also related to roost sites; live trees had larger diameters (p = .) and there was more snag basal area (. m2/ha) in roost plots than the surrounding forest. We surveyed potential roost trees (n = ) for bat activity in  using ultrasonic bat detectors;  had bat activity...

Journal of Wildlife Management, 2006

Knowledge and understanding of bat habitat associations and the responses of bats to forest management are critical for effective bat conservation and management. Few studies have been conducted on bat habitat use in the southeast, despite the high number of endangered and sensitive species in the region. Our objective was to identify important local, stand, and landscape factors influencing bat habitat use in northwestern South Carolina, USA. We hypothesized that use would be greatest 1) at points with relatively sparse vegetation, 2) in early successional and mature stands, and 3) at points close to streams. We also predicted that species would exhibit different patterns of habitat use based on morphology. We placed Anabat II bat detectors at points located in 3 forest types and 3 age classes to record bats from May-August 2004 and. We used an information theoretic approach to determine the variables that best predicted use by bats. Vegetation density at the sample point was the best predictor of overall bat presence in 2004. In 2005 vegetation density and distance to the closest road were the best predictors of overall bat use; the model containing age class also had good support. Bats were more likely to be recorded at points with sparse vegetation, farther from roads, and in early successional stands. Vegetation density was also the best predictor of habitat use by big brown bats (Eptesicus fuscus) and red bats (Lasiurus borealis); both species were far more likely to be recorded at points with sparse vegetation at the sample point. Eastern pipistrelles (Pipistrellus subflavus) were also more likely to be recorded at points with sparse vegetation and in early successional stands. The best predictors of northern long-eared bat (Myotis septentrionalis) habitat use were vegetation density and age class. Northern long-eared bats were more likely to be recorded at points with sparse vegetation and in mature stands. Our results suggest that early successional habitats and small openings and gaps within forest stands provide suitable commuting and foraging bat habitat in northwestern South Carolina. However, mature forests are also important for some species. Forest management practices that provide a variety of age classes across the landscape and that create gaps and openings within mid-and late-successional stands will likely provide suitable habitat for bats in the mountains

2013

Before experimental harvest of the Yellowwood (YW) and Morgan-Monroe (MM) State Forests (Indiana) as part of the Hardwood Ecosystem Experiment, bats were sampled using mist nets at four locations in MM and five locations in YW during each summer 2006 through 2008. Netting locations were adjacent to forest stands scheduled for experimental manipulations following conclusion of netting in 2008. This effort produced 342 bats (in order of abundance): northern myotis (Myotis septentrionalis), eastern red bat (Lasiurus borealis), big brown bat (Eptesicus fuscus), Indiana myotis (M. sodalis), little brown myotis (M. lucifugus), tri-colored bat (Perimyotis subflavus), hoary bat (L. cinereus), and silver-haired bat (Lasionycteris noctivagans). These data provide a baseline to understand how bats are affected by short- and long-term forest manipulations initiated in summer 2008.

Journal of Zoology, 2012

Concurrent recordings of bat calls at the ground and canopy levels were compared to analyse the vertical stratification of habitat use in a broad-leaved deciduous forest in central Europe. The recording effort was 48 nights, by sampling 16 sites three times in 2010. Overall, 2170 call sequences were recorded; 40% of them at the canopy level. Sixteen bat species were identified, 13 of which occurred at ground level and 14 in the canopy. By fitting generalized linear mixed models for seven species and all calls sequences combined, the effects of stratum, time period, ambient temperature and forest structure on bat-calling activity were assessed. Four species preferred the ground level (Barbastella barbastellus, Eptesicus serotinus, Myotis daubentonii, Pipistrellus pygmaeus). M. bechsteinii was the only species which had a significant preference for the canopy level in the pregnancy, lactation and post-lactation period, whereas two further species (M. alcathoe, P. pipistrellus) showed a significant canopy preference in at least one period. Therefore, canopy sampling should be undertaken when aiming at monitoring such species for conservation purposes. Populations of certain target species will be underestimated by ground recordings alone.

2006

Conservation Assessments for Five Forest Bat Species in the Eastern United States Monitor Population Trend and Abundance 1. Develop and validate methods to assess abundance of forest bat species during nonhibernating periods. (High priority.) 2. Develop a long-term population monitoring strategy for nonhibernating periods. (High priority but subsequent to #1 above.) Determine Terrestrial Habitat Relationships 1. Determine summer habitat use relationships (roosting and foraging) for forest bats across multiple spatial and temporal scales within the range of each species, by demographic group. This effort should be coordinated across the range of the species to provide for adequate sample size to evaluate meaningful relationships. (High priority but subsequent to Monitor Population Trend and Abundance section.) 2. Evaluate habitat quality by associating habitat parameters with reproductive success. (Due to the patchy distribution of most forest bat species, design studies using baseline or pre-treatment to post-treatment at the same location.)

Little is known about the effects that oak forest regeneration treatments consisting of a combination of shelterwood harvesting and prescribed fire have on bats, despite increasing use of these treatments. We quantified changes in bat activity levels in relation to oak forest regeneration treatments consisting of harvesting at 50% and 70% retention levels and prescribed fire in two upland Appalachian hardwood forests in Ohio. We monitored bat activity immediately post-harvest, three growing seasons post-harvest, and after application of prescribed fire to harvested stands before the fourth growing season. Total bat activity levels were higher in thinned and thinned and burned treatments than in unthinned controls in all years, but did not differ between harvest treatment levels immediately post-harvest, three growing seasons post-harvest, or between harvest treatment levels within years. Total bat activity post-prescribed fire changed only in the 50% retention harvest treatment blocks, wherein activity decreased. Activity levels of big brown (Eptesicus fuscus) bats were greater in harvested treatment blocks than controls in all years. Activity levels of eastern red (Lasiurus borealis), and Myotis spp. and tri-colored (Perimyotis subflavus) collectively did not differ among treatment blocks post-fire, but were greater in harvested treatment blocks than controls three growing seasons post-harvest. Community composition was strongly related to vegetation volume, with eastern red bats and Myotis and tri-colored bats displaying positive relationships with clutter in low height strata, and big brown bats displaying a negative relationship with clutter in all height strata. The positive relationship between eastern red and Myotis and tri-colored bats and clutter in low height strata may explain why activity levels of these species decreased post-prescribed fire. Our study suggests that the harvesting component of oak forest regeneration treatments may benefit bats for several years, and that while bat activity levels may decline post-prescribed fire, overall activity levels are nonetheless greater than in unthinned areas.

Bats are under threat from habitat loss, energy development, and the disease white-nose syndrome. The North American Bat Monitoring Program (NABat) suggests standardized, large scale monitoring to benefit ecologists and managers. Our first objective was to determine the efficacy of NABat in South Carolina. Detection probabilities differ within and among species and among survey conditions. Thus, our second objective was to determine factors affecting detection probabilities. Finally, effective management strategies addressing large scale threats require landscape scale analyses. Thus, our third objective was to conduct state-wide assessments of environmental factors influencing landscape occupancy and generate predicted distributions. We conducted NABat acoustic surveys across South Carolina from mid-May through July 2015 and 2016. To determine the efficacy of NABat, we compared species detections to known distributions based on historical records, and to predicted distributions based on environmental occupancy models. We detected some species throughout their ranges and others in ≤ 50% of cells within their ranges, and detected some species outside their ranges. Thus, NABat monitoring may be suitable for many species but may not be suitable for species with echolocation calls that are difficult to detect or identify, and may also reveal new information about species distributions. To determine factors that affected detection, we evaluated support for detection models. We found that detection covariates greatly varied among species, but most species had higher detection probabilities at stationary points than mobile transects. Our results suggested that effects of factors on detection probabilities were based on biological and behavioral characteristics of species, which indicated the importance of monitoring survey variables and accounting for them in analyses. To assess effects of environmental factors on occupancy, we evaluated temporally dynamic occupancy models. Occupancy probability differed among ecoregions for northern yellow bats (Dasypterus intermedius) and Myotis species. Hoary bats (Lasiurus cinereus) were negatively associated with forest edge density. We found no significant effects of habitat conditions for five species. Thus, for some species, site-use analyses of NABat data may be more appropriate than grid-based occupancy analyses. However, predicted distributions closely matched species habitat associations. Our findings can improve future monitoring efforts and inform conservation priorities.

Forest Ecology and Management, 2002

As part of a bat ecology research effort in managed forests, we tracked seven lactating northern long-eared bats (Myotis septentrionalis Trouessart) to 12 roost trees used by maternity colonies ranging in size from 11 to 65 individuals in the central Appalachians of West Virginia. Lactating females switched among roosts on average every 5 days. Roosts were located in nine tree species, with 11 roosts in tree cavities and 1 under exfoliating bark. Eight of the roosts were located in snags; the other four were located in cavities in living trees. Black locust (Robinia pseudo-acacia L.) snags were selected as a roost sites more than expected based on their occurrence in the forests we surveyed. Only 3 of the 24 habitat characteristics differed between actual roost trees and randomly located cavity trees. Structurally, actual roosts tended to be closer to neighboring trees than did suitable roosts in randomly located cavity trees. Tree species was an important factor that influenced roost tree selection, with black locusts being used significantly more than expected based on their abundance across the managed forest landscape we studied. All northern long-eared bat roosts were located in or below the forest canopy which suggests that solar exposure may not be as critical for selection of roost trees by maternity colonies of this species as opposed to other species of tree-roosting bat at more northern latitudes in North America. Although many previous studies have demonstrated the importance of oldgrowth habitat in providing roosting habitat for tree-roosting bats, use of roosting habitat and characteristics of roost sites have been little documented within intensively managed forests. Our research indicates that in managed, Allegheny hardwoodnorthern hardwood forests of the central Appalachians, short-lived, early successional species such as black locust may provide suitable roosting habitat for northern long-eared bats, as well as other species of bats. Published by Elsevier Science B.V.

Forest Ecology and Management, 2013

and sharing with colleagues.

As part of a study examining the effects of silvicultural treatments for oak regeneration on habitat use by bats, we surveyed forest stands prior to the implementation of treatments in two state forests in Indiana. Interior forest sites corresponding to areas designated for silvicultural treatments were surveyed for 2 nights each during the summers of 2007 and 2008. Additionally, three types of existing forest openings (pre-existing harvest openings, forest edges, and open corridors) were surveyed during 2007 in the same area. We assessed bat habitat use by recording echolocation calls using ANABAT II bat detectors. We characterized a location as experiencing high levels of activity, experiencing low levels of activity, or being unused by a species of bat based on recorded call minutes. We used occupancy models to account for differences in detection probability. Stands designated for uneven-aged harvest had a greater probability of experiencing high activity by a species of bat when compared to areas designated for other silvicultural treatments. Existing forest openings had probabilities of high activity levels that were similar to each other, but high activity levels in these habitats were less likely for Indiana myotis (Myotis sodalis) and northern myotis (M. septentrionalis) when compared to forest interior locations. At interior forest sites, northern myotis were more likely than other species to have high activity levels. These results provide some insight into the potential responses of bats to forest management practices and serve as a baseline for future experimental treatments.

Sustainability

Bats are estimated to provide between $3.7 and $53 billion annually in ecosystem services in the U.S.A. Determining how bats use land for foraging is important in planning agricultural landscapes to increase their presence and role in insect pest control. A research project was established in 2016 and 2017 to determine bat populations and activity differences between different land use management systems. Bat activity was monitored in 10 conventionally and organically managed systems in the presence of, and at a distance from the tree line. Two acoustic monitoring devices were used to record ultrasonic echolocation calls of bats. Organic systems without tree line had 67% and 45% greater bat passes than conventional systems without tree line as detected by the two devices. However, the conventional system with tree line had 61% and 59% greater bat passes than organic systems, attributed to known roosting sites in the area. Mean bat passes of 73.4 and 30 were recorded respectively at ...

Northeastern Naturalist, 2012

Bats vary their activity with different features of habitat, resource availability, predation risk, and other factors. Agricultural fi elds may provide an abundance of insect prey, but are also risky habitats due to their exposure. How bats use mixed landscapes is important information for biologists, as increasing development affects the amount of suitable habitat and impacts bat populations in the region. Using acoustic recording, we monitored relative bat activity in open areas and edges of the woodland/farmland interface of agricultural fi elds in Kent County, DE. We examined bat activity among different sites, in openings versus edges, among crop types, relative to nearby forest fragment size and shape, and under different weather conditions. Bat activity was signifi cantly higher along edges than in the open in the agricultural fi elds for passes/night, but we found no differences among crop types or sites and no interaction effects. We also found no effect of size or amount of edge of a fragment on bat activity. We found signifi cant negative correlations between passes and temperature and wind speed, and signifi cant positive correlations between passes and relative humidity and barometric pressure. Bats use agricultural areas for foraging, and the woodland interfaces along these fi elds are important for bat activity. This study provides data that may help engender conservation practices, such as retention of forested edges and maintenance of tree lines, and perhaps crop selection and pest control management, in the region's farming community.

Reinstating forestry practices, such as coppicing, thinning the understorey and grazing, has become a key element of proposals for improving the conservation value of broadleaved woodlands in Europe. However, the consequences of such woodland management for bats are poorly understood because of a lack of knowledge concerning their habitat requirements. We studied the brown longeared bat Plecotus auritus in South East England to determine how their patterns of habitat use could inform conservation management. Radio-tracking of 38 adult females showed that they foraged primarily in woodland and that each had a foraging area (mean = 4.4 ha) that they returned to on successive nights. Core foraging areas (mean = 2.1 ha) were characterized by more cover and greater species diversity in the understorey layer than more peripheral areas. Hedgerows were also used for foraging in the late summer and autumn. Most conservation activities for this species have focused on protecting roosts in houses and other buildings. While such protection is important for bat conservation, efforts should also be made to protect foraging habitats in woodlands by maintaining cover of native species in the understorey layer and hedgerows that provide connectivity between woodland patches. Common conservation management practices, such as reinstating coppicing or grazing in semi-natural broadleaved woodlands, could be detrimental for P. auritus and other woodland bats. Their impact on bats should be tested experimentally before they are widely promoted as a woodland conservation strategy.