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Sex differences in body color (i.e., sexual dichromatism) are rare in bats and, more broadly, in mammals. The eastern red bat (Lasiurus borealis) is a common tree‐roosting bat that occupies much of North America and has long been described as sexually dichromatic. However, previous research on this species found that absolute body size and collection year were better predictors of fur color in preserved specimens than sex. We revisited this issue and photographed 82 live eastern red bats under standardized conditions, then used image analysis to quantify pelage hue, saturation, and value. We used an information theoretic approach to evaluate four competing hypotheses about the principal drivers of color differences in the fur of eastern red bats. Our analyses demonstrated that sex was a better predictor of pelage color than body size; males had redder, more saturated, and lighter pelages than females. Additionally, the fur color of juvenile versus adult bats differed somewhat, as juveniles were darker than adults. In general, absolute body size (i.e., forearm length in bats) was a poor predictor of color in live eastern red bats. In an exploratory post‐hoc analysis, we confirm that fur color is related to body mass (i.e., a proxy for body condition in bats), suggesting color might serve as a sexually selected signal of mate quality in this partially diurnal species. Future work should investigate the functional role of sexual dichromatism in this species, which could be related to signaling or possibly thermoregulation. [ABSTRACT FROM AUTHOR]

Abstract Sex differences in body color (i.e., sexual dichromatism) are rare in bats and, more broadly, in mammals. The eastern red bat (Lasiurus borealis) is a common tree‐roosting bat that occupies much of North America and has long been described as sexually dichromatic. However, previous research on this species found that absolute body size and collection year were better predictors of fur color in preserved specimens than sex. We revisited this issue and photographed 82 live eastern red bats under standardized conditions, then used image analysis to quantify pelage hue, saturation, and value. We used an information theoretic approach to evaluate four competing hypotheses about the principal drivers of color differences in the fur of eastern red bats. Our analyses demonstrated that sex was a better predictor of pelage color than body size; males had redder, more saturated, and lighter pelages than females. Additionally, the fur color of juvenile versus adult bats differed somewhat, as juveniles were darker than adults. In general, absolute body size (i.e., forearm length in bats) was a poor predictor of color in live eastern red bats. In an exploratory post‐hoc analysis, we confirm that fur color is related to body mass (i.e., a proxy for body condition in bats), suggesting color might serve as a sexually selected signal of mate quality in this partially diurnal species. Future work should investigate the functional role of sexual dichromatism in this species, which could be related to signaling or possibly thermoregulation.

Abstract Along the mid-Atlantic coast of the United States, eastern red bats (Lasiurus borealis) are present during fall mating and migration, though little is currently known about most aspects of bat migration. To reveal migration patterns, and understand drivers of over-water flight, we captured and radio-tagged 115 eastern red bats using novel technology, and subsequently tracked and described their movements throughout the region. We compared over-water flight movements to randomly generated patterns using a use-availability framework, and subsequently used a generalized linear mixed effects model to assess the relationship of over-water flight to atmospheric variables. We used hidden Markov models to assess daily activity patterns and site residency. Most bats with long-distance movements traveled in a southwesterly direction, however path vectors were often oriented interior toward the continental landmass rather than along the coastline. We observed that some bats transited wide sections of the Chesapeake and Delaware bays, confirming their ability to travel across large water bodies. This over-water flight typically occurred in the early hours of the night and during favorable flying conditions. If flight over large water bodies is a proxy for over-ocean flight, then collision risk at offshore wind turbines – a major source of migratory bat fatalities – may be linked nightly to warm temperatures that occur early in the fall season. Risk, then, may be somewhat predictable and manageable with mitigation options linking wind-energy operation to weather conditions and seasonality.

Along the mid-Atlantic coast of the United States, eastern red bats (Lasiurus borealis) are present during fall mating and migration, though little is currently known about most aspects of bat migration. To reveal migration patterns, and understand drivers of over-water flight, we captured and radio-tagged 115 eastern red bats using novel technology, and subsequently tracked and described their movements throughout the region. We compared over-water flight movements to randomly generated patterns using a use-availability framework, and subsequently used a generalized linear mixed effects model to assess the relationship of over-water flight to atmospheric variables. We used hidden Markov models to assess daily activity patterns and site residency. Most bats with long-distance movements traveled in a southwesterly direction, however path vectors were often oriented interior toward the continental landmass rather than along the coastline. We observed that some bats transited wide sections of the Chesapeake and Delaware bays, confirming their ability to travel across large water bodies. This over-water flight typically occurred in the early hours of the night and during favorable flying conditions. If flight over large water bodies is a proxy for over-ocean flight, then collision risk at offshore wind turbines – a major source of migratory bat fatalities – may be linked nightly to warm temperatures that occur early in the fall season. Risk, then, may be somewhat predictable and manageable with mitigation options linking wind-energy operation to weather conditions and seasonality. [ABSTRACT FROM AUTHOR]

White-nose syndrome (WNS) is an emerging fungal epizootic disease that has caused large-scale mortality in several species of North American bats. The fungus that causes WNS, Pseudogymnoascus destructans (Pd), has also been detected in bat species without diagnostic signs of WNS. Although these species could play a role in WNS spread, understanding of the spatial and temporal extents of Pd occurrence on WNS-resistant species is limited. This study evaluated the presence of Pd on 272 individuals of three species of migratory tree-roosting bats: hoary (Lasiurus cinereus), eastern red (Lasiurus borealis), and silver-haired (Lasionycteris noctivagans) bats, obtained opportunistically during summer and autumn from throughout much of their ranges in North America. We also compared tissue sampling protocols (i.e., tissue swabbing, fur swabbing, and DNA extraction of excised wing tissue). We detected Pd on three eastern red bats from Illinois and Ohio, US, one silver-haired bat from West Virginia, US, and one hoary bat from New York, US, all via DNA extracted from wing tissue of carcasses. These results document the first publicly reported detections of Pd on a hoary bat and on migratory bats during the autumn migratory period, and demonstrate the potential for using carcasses salvaged at wind-energy facilities to monitor for Pd. [ABSTRACT FROM AUTHOR]

Abstract Background White-nose Syndrome (WNS) has reduced the abundance of many bat species within the United States’ Mid-Atlantic region. To determine changes within the National Park Service National Capital Region (NCR) bat communities, we surveyed the area with mist netting and active acoustic sampling (2016–2018) and compared findings to pre-WNS (2003–2004) data. Results The results indicated the continued presence of the threatened Myotis septentrionalis (Northern Long-eared bat) and species of conservation concern, including Perimyotis subflavus (Tri-colored bat), Myotis leibii (Eastern Small-footed bat) and Myotis lucifugus (Little Brown bat). However, we documented a significant reduction in the abundance and distribution of M. lucifugus and P. subflavus, a decrease in the distribution of M. septentrionalis, and an increase in the abundance of Eptesicus fuscus (Big Brown bat). Conclusions Documented post-WNS M. septentrionalis recruitment suggests that portions of the NCR may be important bat conservation areas. Decreases in distribution and abundance of P. subflavus and M. lucifugus indicate probable extirpation from many previously occupied portions of the region.

Acoustic data are often used to describe bat activity, including habitat use within the summer reproductive period. These data inform management activities that potentially impact bats, currently a taxa of high conservation concern. To understand the relationship between acoustic and reproductive timing, we sampled big brown bats (Eptesicus fuscus) and eastern red bats (Lasiurus borealis) on 482 mist-netting and 35,410 passive acoustic sampling nights within the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia, 2015–2018. We documented the proportion of female, pregnant, lactating, and juvenile big brown and eastern red bats within each mist-net sampling event and calculated locally estimated non-parametric scatterplot smoothing (LOESS) lines for each reproductive and acoustic dataset. We compared the peak in acoustic activity with the peaks of each reproductive condition. We determined that the highest levels of acoustic activity within the maternity season were most associated with the period wherein we captured the highest proportions of lactating bats, not juvenile bats, as often assumed. [ABSTRACT FROM AUTHOR]

White‐nose syndrome (WNS) is a disease caused by the fungus Pseudogymnoascus destructans which has resulted in the deaths of millions of bats across eastern North America. To date, hibernacula counts have been the predominant means of tracking the spread and impact of this disease on bat populations. However, an understanding of the impacts of WNS on demographic parameters outside the winter season is critical to conservation and recovery of bat populations impacted by this disease. We used long‐term monitoring data to examine WNS‐related impacts to summer populations in West Virginia, where WNS has been documented since 2009. Using capture data from 290 mist‐net sites surveyed from 2003 to 2019 on the Monongahela National Forest, we estimated temporal patterns in presence and relative abundance for each bat species. For species that exhibited a population‐level response to WNS, we investigated post‐WNS changes in adult female reproductive state and body mass. Myotis lucifugus (little brown bat), M. septentrionalis (northern long‐eared bat), and Perimyotis subflavus (tri‐colored bat) all showed significant decreases in presence and relative abundance during and following the introduction of WNS, while Eptesicus fuscus (big brown bat) and Lasiurus borealis (eastern red bat) responded positively during the WNS invasion. Probability of being reproductively active was not significantly different for any species, though a shift to earlier reproduction was estimated for E. fuscus and M. septentrionalis. For some species, body mass appeared to be influenced by the WNS invasion, but the response differed by species and reproductive state. Results suggest that continued long‐term monitoring studies, additional research into impacts of this disease on the fitness of WNS survivors, and a focus on providing optimal nonwintering habitat may be valuable strategies for assessing and promoting recovery of WNS‐affected bat populations. [ABSTRACT FROM AUTHOR]

Understanding seasonal variation in the distribution and movement patterns of migratory species is essential to monitoring and conservation efforts. While there are many species of migratory bats in North America, little is known about their seasonal movements. In terms of conservation, this is important because the bat fatalities from wind energy turbines are significant and may fluctuate seasonally. Here we describe seasonally resolved distributions for the three species that are most impacted by wind farms (Lasiurus borealis (eastern red bat), L. cinereus (hoary bat) and Lasionycteris noctivagans (silver-haired bat)) and use these distributions to infer their most likely migratory pathways. To accomplish this, we collected 2,880 occurrence points from the Global Biodiversity Information Facility over five decades in North America to model species distributions on a seasonal basis and used an ensemble approach for modeling distributions. This dataset included 1,129 data points for L. borealis, 917 for L. cinereus and 834 for L. noctivagans. The results suggest that all three species exhibit variation in distributions from north to south depending on season, with each species showing potential migratory pathways during the fall migration that follow linear features. Finally, we describe proposed migratory pathways for these three species that can be used to identify stop-over sites, assess small-scale migration and highlight areas that should be prioritized for actions to reduce the effects of wind farm mortality.

Background: White-nose Syndrome (WNS) has reduced the abundance of many bat species within the United States' Mid-Atlantic region. To determine changes within the National Park Service National Capital Region (NCR) bat communities, we surveyed the area with mist netting and active acoustic sampling (2016–2018) and compared findings to pre-WNS (2003–2004) data. Results: The results indicated the continued presence of the threatened Myotis septentrionalis (Northern Long-eared bat) and species of conservation concern, including Perimyotis subflavus (Tri-colored bat), Myotis leibii (Eastern Small-footed bat) and Myotis lucifugus (Little Brown bat). However, we documented a significant reduction in the abundance and distribution of M. lucifugus and P. subflavus, a decrease in the distribution of M. septentrionalis, and an increase in the abundance of Eptesicus fuscus (Big Brown bat). Conclusions: Documented post-WNS M. septentrionalis recruitment suggests that portions of the NCR may be important bat conservation areas. Decreases in distribution and abundance of P. subflavus and M. lucifugus indicate probable extirpation from many previously occupied portions of the region. [ABSTRACT FROM AUTHOR]

Understanding seasonal variation in the distribution and movement patterns of migratory species is essential to monitoring and conservation efforts. While there are many species of migratory bats in North America, little is known about their seasonal movements. In terms of conservation, this is important because the bat fatalities from wind energy turbines are significant and may fluctuate seasonally. Here we describe seasonally resolved distributions for the three species that are most impacted by wind farms (Lasiurus borealis (eastern red bat), L. cinereus (hoary bat) and Lasionycteris noctivagans (silver-haired bat)) and use these distributions to infer their most likely migratory pathways. To accomplish this, we collected 2,880 occurrence points from the Global Biodiversity Information Facility over five decades in North America to model species distributions on a seasonal basis and used an ensemble approach for modeling distributions. This dataset included 1,129 data points for L. borealis, 917 for L. cinereus and 834 for L. noctivagans. The results suggest that all three species exhibit variation in distributions from north to south depending on season, with each species showing potential migratory pathways during the fall migration that follow linear features. Finally, we describe proposed migratory pathways for these three species that can be used to identify stop-over sites, assess small-scale migration and highlight areas that should be prioritized for actions to reduce the effects of wind farm mortality. [ABSTRACT FROM AUTHOR]

Acoustic data are often used to describe bat activity, including habitat use within the summer reproductive period. These data inform management activities that potentially impact bats, currently a taxa of high conservation concern. To understand the relationship between acoustic and reproductive timing, we sampled big brown bats (Eptesicus fuscus) and eastern red bats (Lasiurus borealis) on 482 mist-netting and 35,410 passive acoustic sampling nights within the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia, 2015–2018. We documented the proportion of female, pregnant, lactating, and juvenile big brown and eastern red bats within each mist-net sampling event and calculated locally estimated non-parametric scatterplot smoothing (LOESS) lines for each reproductive and acoustic dataset. We compared the peak in acoustic activity with the peaks of each reproductive condition. We determined that the highest levels of acoustic activity within the maternity season were most associated with the period wherein we captured the highest proportions of lactating bats, not juvenile bats, as often assumed.

The expansion of the wind energy industry has had benefits in terms of increased renewable energy production but has also led to increased mortality of migratory bats due to interactions with wind turbines. A key question that could guide bat-related management activities is identifying the geographic origin of bats killed at wind-energy facilities. Generating this information requires developing new methods for identifying the geographic sources of individual bats. Here we explore the viability of assigning geographic origin using trace element analyses of fur to infer the summer molting location of eastern red bats (Lasiurus borealis). Our approach is based on the idea that the concentration of trace elements in bat fur is related through the food chain to the amount of trace elements present in the soil, which varies across large geographic scales. Specifically, we used inductively coupled plasma–mass spectrometry to determine the concentration of fourteen trace elements in fur of 126 known-origin eastern red bats to generate a basemap for assignment throughout the range of this species in eastern North America. We then compared this map to publicly available soil trace element concentrations for the U.S. and Canada, used a probabilistic framework to generate likelihood-of-origin maps for each bat, and assessed how well trace element profiles predicted the origins of these individuals. Overall, our results suggest that trace elements allow successful assignment of individual bats 80% of the time while reducing probable locations in half. Our study supports the use of trace elements to identify the geographic origin of eastern red and perhaps other migratory bats, particularly when combined with data from other biomarkers such as genetic and stable isotope data.

Relatively high mortality of migratory bats at wind energy facilities has prompted research to understand the underlying spatial and temporal factors, with the goal of developing more effective mitigation approaches. We examined acoustic recordings of echolocation calls at 12 sites and post-construction carcass survey data collected at 10 wind energy facilities in Ontario, Canada, to quantify the degree to which timing and regional-scale weather predict bat activity and mortality. Rain and low temperatures consistently predicted low mortality and activity of big brown bats (Eptesicus fuscus) and three species of migratory tree bats: hoary bat (Lasiurus cinereus), eastern red bat (L. borealis), and silver-haired bat (Lasionycteris noctivagans). Bat activity occurred in waves with distinct peaks through the season; regardless of seasonal timing, most activities occurred in the first half of the night. We conclude that wind energy facilities could adopt a novel and more effective curtailment strategy based on weather and seasonal and nocturnal timing that would minimize mortality risks for bats while increasing the opportunities for power generation, relative to the mitigation strategy of increasing cut-in wind speed to 5.5 m/s.

Most species of bats give birth to only 1 pup each year, although Eastern red bats (Lasiurus borealis) can produce up to 5 pups per litter. Offspring in a single litter have been documented to be at different stages of development, suggesting that multiple paternity occurs. We tested the null hypothesis of genetic monogamy in red bats using 6 autosomal microsatellites and 1 X-linked microsatellite from 31 parent/offspring groups for a total of 128 bats. We sampled both pregnant females and mothers with pups that were obtained from bats submitted to departments of health in Oklahoma and Texas for rabies testing. Multiple paternity was assessed using a maximum-likelihood approach, hypothesis testing, and X-linked locus exclusion. The mean polymorphic information content of our markers was high (0.8819) and combined non-exclusion probability was low (0.00027). Results from the maximum-likelihood approach showed that 22 out of 31 (71%) parent/offspring groups consisted of half siblings, hypothesis testing rejected full sibship in 61% of parent/offspring groups, and X-linked locus exclusion suggested multiple paternity in at least 12 parent/offspring groups, rejecting our hypothesis of genetic monogamy. This frequency of multiple paternity is the highest reported thus far for any bat species. High levels of multiple paternity have the potential to impact interpretations of genetic estimates of effective population size in this species. Further, multiple paternity might be an adaptive strategy to allow for increased genetic variation and large litter size, which would be beneficial to a species threatened by population declines from wind turbines. [ABSTRACT FROM AUTHOR]

White-nose syndrome (WNS) affects bats primarily in winter, with Pseudogymnoascus destructans, the fungus that causes WNS, growing on bats in colder climates as they are hibernating. As a result, nearly all disease investigations have been conducted on bats in the winter or as they are emerging in spring. Although P. destructans has been detected on bats during the summer season, the seasonal dynamics of infection during this period remain poorly understood. To test for the presence of P. destructans during the summer season, we sampled bats that were free flying from June 2017 to September 2017 and also sampled bats from a maternity roost in August and outside a known hibernaculum in September. We collected skin swabs from the muzzle and forearm of bats, and using real-time PCR methods, we detected P. destructans DNA on 16% (12/76) of bats sampled in Wisconsin, US, including juvenile little brown bats (Myotis lucifugus) from bat house maternity roosts, and free-flying adult bats of two species captured in June, the little brown bat and the migratory eastern red bat (Lasiurus borealis). These data illustrated the potential for P. destructans to be transferred and dispersed among bats during the summer and highlighted the complex seasonal dynamics associated with this pathogen. [ABSTRACT FROM AUTHOR]

An unanticipated impact of wind-energy development has been large-scale mortality of insectivorous bats. In eastern North America, where mortality rates are among the highest in the world, the hoary bat ( Lasiurus cinereus) and the eastern red bat ( L. borealis) comprise the majority of turbine-associated bat mortality. Both species are migratory tree bats with widespread distributions; however, little is known regarding the geographic origins of bats killed at wind-energy facilities or the diversity and population structure of affected species. We addressed these unknowns by measuring stable hydrogen isotope ratios (δ2H) and conducting population genetic analyses of bats killed at wind-energy facilities in the central Appalachian Mountains ( USA) to determine the summering origins, effective size, structure, and temporal stability of populations. Our results indicate that ~1% of hoary bat mortalities and ~57% of red bat mortalities derive from non-local sources, with no relationship between the proportion of non-local bats and sex, location of mortality, or month of mortality. Additionally, our data indicate that hoary bats in our sample consist of an unstructured population with a small effective size ( Ne) and either a stable or declining history. Red bats also showed no evidence of population genetic structure, but in contrast to hoary bats, the diversity contained in our red bat samples is consistent with a much larger Ne that reflects a demographic expansion after a bottleneck. These results suggest that the impacts of mortality associated with intensive wind-energy development may affect bat species dissimilarly, with red bats potentially better able to absorb sustained mortality than hoary bats because of their larger Ne. Our results provide important baseline data and also illustrate the utility of stable isotopes and population genetics for monitoring bat populations affected by wind-energy development. [ABSTRACT FROM AUTHOR]

Bats face numerous threats associated with global environmental change, including the rapid expansion of wind-energy facilities, emerging infectious disease, and habitat loss. An understanding of the movement and migration patterns of these highly dispersive animals would help reveal how spatially localized the impacts from these threats are likely to be on bat populations, thus aiding in their conservation. Stable hydrogen isotope ratios (δ2H) can be used to infer regions where bats have foraged during the summer molt season, thus allowing an assessment of summering location and distance of movement of bats sampled during other times of year. However, a major impediment to the application of δ2H for inference of bat movements is that the relationship between δ2H of bat hair and precipitation tends to be species specific and is still unknown for some key species of conservation concern. We addressed this issue by using geo-referenced museum specimens to calibrate the relationship between δ2H of hair (δ2Hhair) and long-term δ2H of growing-season precipitation (δ2HGSprecip) at the site of collection for eastern red bats (Lasiurus borealis), one of the main species of bats experiencing large numbers of fatalities at wind-energy facilities in North America. Based on comparison of δ2Hhair and δ2HGSprecip values for males we estimated a period of molt of June 14–August 7. Within this period, male and female red bats exhibited a significant positive relationship between δ2Hhair and δ2HGSprecip. These results establish the relationship between δ2Hhair and δ2HGSprecip for red bats, which is necessary for the use of δ2Hhair to infer the movement and migration patterns of this important species. These results provide a critical resource to conservation biologists working to assess the impacts of environmental change on bat populations.

ABSTRACT Resource selection by animals influences ecological processes such as dispersal, reproduction, foraging, and migration. Little information exists regarding foraging resource selection by bats during the maternity season. We evaluated support for effects of landcover type, landform, and landscape pattern on resource selection by individual foraging female eastern red bats ( Lasiurus borealis) during the maternity period and compared resource utilization for all individuals pooled (population level), individuals grouped by geographic location, and individuals grouped by stage of lactation (early, mid, and late). We used a resource utilization function (RUF) to relate landcover and landscape attributes to the utilization distributions of individual bats estimated by the fixed-kernel method. We radio-tracked 64 lactating red bats and estimated utilization distributions for 52 individuals. Mean home range size ranged from 1,041 to 1,588 ha from late to mid lactation. The global RUF model was significantly better than the null RUF model for 36 (70%) individuals and the magnitude and direction of coefficients varied among individuals. Resource utilization at the population level was, on average, positively related to ridges and upland drainage landforms, water landcover, and road density; and negatively related to urban and nonforest landcover and distance to edge. Resource use differed between geographic areas by canopy cover, water landcover, and road density. Canopy closure was positively related to RUF in both areas but was greater in the south area. Percent water negatively related to RUF in the north area and positively related in the south area. Road density had a positive relationship in the north and negative relationship in the south with RUF. We did not find a difference in mean RUF coefficients among lactation groups except for canopy cover. On average, canopy cover had a positive effect on use by bats during early and mid-lactation but a negative effect during late lactation. We suggest that management for red bats consider landscape components and provide a range of composition and structural diversity to enhance foraging use by red bats. In highly forested landscapes, gaps or openings may provide forest edges that are important for foraging and commuting. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Bat mortality has been reported at industrial scale wind facilities across North America, with tree-roosting bats accounting for most fatalities, but no data exist for central Canada. We quantified rates of mortality at a wind energy facility in Manitoba, Canada by conducting standardized carcass searches corrected for searcher efficiency and scavenging from mid-August to mid-September 2007. We found that mortality was consistent with, but qualitatively higher than that at comparable wind facilities in western Canada. Mortality of the species most commonly killed, Silver-haired Bats, was evenly distributed across the wind facility, but mortality of Hoary and Eastern Red Bats was higher at some turbines than others. [ABSTRACT FROM AUTHOR]

Abstract: Order Chiroptera is a unique group of mammals whose members have attained self-powered flight as their main mode of locomotion. Much speculation persists regarding bat evolution; however, lack of sufficient molecular data hampers evolutionary and conservation studies. Of ~1200 species, complete mitochondrial genome sequences are available for only eleven. Additional sequences should be generated if we are to resolve many questions concerning these fascinating mammals. Herein, we describe the complete mitochondrial genomes of three bats: Corynorhinus rafinesquii, Lasiurus borealis and Artibeus lituratus. We also compare the currently available mitochondrial genomes and analyze codon usage in Chiroptera. C. rafinesquii, L. borealis and A. lituratus mitochondrial genomes are 16438bp, 17048bp and 16709bp, respectively. Genome organization and gene arrangements are similar to other bats. Phylogenetic analyses using complete mitochondrial genome sequences support previously established phylogenetic relationships and suggest utility in future studies focusing on the evolutionary aspects of these species. Comprehensive analyses of available bat mitochondrial genomes reveal distinct nucleotide patterns and synonymous codon preferences corresponding to different chiropteran families. These patterns suggest that mutational and selection forces are acting to different extents within Chiroptera and shape their mitochondrial genomes. [Copyright &y& Elsevier]

Little is known about the diversity, distribution, and relative abundance of bats in northeastern Alberta, Canada. Between 1999 and 2007, we conducted summer bat surveys in the Athabasca and Cold Lake oil sands regions of northeastern Alberta, in response to increased industrial development and a need for greater understanding of species occurrences. We used mist nets (242 sites over 157 nights) and acoustic monitoring (920 sites over 126 nights) to determine the diversity and distribution of bats in the region. We captured 577 bats, representing 5 species, including: 260 Northern Myotis (Myotis septentrionalis); 193 Little Brown Myotis (M. lucifugus); 101 Silver-haired Bats (Lasionycteris noctivagans); 12 HoaryBats (Lasiurus cinereus); and 11 Eastern Red Bats (L. borealis). Data from Anabat™ echolocation detectors indicated the highest activity for unclassified Myotis, Little Brown Myotis, Big Brown Bats (Eptesicus fuscus)/Silver-haired Bats, and Northern Myotis. Results suggest that the Northern Myotis may be more common in northeastern Alberta than previously thought. Based on the combined capture and echolocation data, Eastern Red Bats and Hoary Bats may be more common, or have increased ranges, than previously considered. Although expected to be relatively common, our failure to capture Big Brown Bats suggests that this species may be absent from the study area. Captures of adult males for all 3 migratory bat species (Eastern Red Bats, Hoary Bats, and Silver-haired Bats) represent the most northerly records in western Canada of adult males. This paper demonstrates the value in combining short-term, localized survey data such that more regional trends in the diversity, distribution, and relative abundance of bats can be better understood. [ABSTRACT FROM AUTHOR]

Mammalian pelage color can vary among individuals of many species, although this intraspecific variation is often overlooked by researchers, perhaps because of its sometimes subtle nature and difficulty in assessing it quantitatively. Thus, such variation is rarely studied in mammals, and this is especially true within the order Chiroptera, where there has been very little empirical research. We examined museum specimens of red bats (Lasiurus borealis, family Vespertilionidae) from Georgia, USA, to determine the extent of sexual dimorphism in pelage color and to explore possible associations between body size and pelage color. We photographed 54 specimens under uniform lighting, and used an image analysis program to measure pelage hue on the uropatagium region, which is fully furred in members of the genus Lasiurus. Statistical analyses of pelage hue scores showed males had significantly redder pelage than females when considered alone, but when examined together with effects of body size and collection year, sex was not significant, and collection year and body size were. More recent specimens tended to be less red than older specimens, which might indicate a wearing of the buffy tips of hairs from older specimens, and smaller bats of both sexes tended to be more red. These interesting findings are encouraging and we suggest that future explorations into intraspecific variation in pelage color of bats using this or similar approaches are warranted to clarify the significance of the patterns. This study also demonstrated that care must be taken in analyses of mammalian pelage color from older museum skins, or at least that researchers must take into account the age of the specimens [Current Zoology 56 (4): 401-405, 2010]. [ABSTRACT FROM AUTHOR]

I summarized data on eastern red bats (Lasiurus borealis), hoary bats (Lasiurus cinereus), and silver-haired bats (Lasionycteris noctivagans) that were obtained by mistnetting in the Lower Peninsula of Michigan over a 32-year span (1978-2009) to test published predictions, partly or wholly based on museum specimens, that adult sex ratios in summer are female-biased. Males were more common in the netting sample than females among silver-haired bats (88%; n = 57) and eastern red bats (70%; n = 458), whereas male and female hoary bats (n = 40) were equally abundant. Silver-haired bats and male hoary bats were more common north of a line separating the Deciduous Forest Biome and a transition to the Coniferous Forest Biome. The presence of male-dominated populations of all species at low-elevation sites in northern Lower Michigan suggested that distribution of the sexes in each species is more complex than previously thought. The sex ratio of adult eastern red bats was more skewed in July (74% male) than in June (58%), which might indicate late northward migration by males. [ABSTRACT FROM AUTHOR]

Stable hydrogen isotopes (δDs) in metabolically inert tissues such as feathers and hair provide a set of endogenous markers that may be useful for establishing migratory connectivity in animals. We tested the assumption of a clear relationship between δD values of growing-season-weighted average precipitation (δDp) derived from 2 geographic information system (GIS) models or latitude (LAT) and δD values in bat hair (δDh), and examined intra- and interspecific variation in δDh of 4 bat species in the eastern United States. We analyzed 251 hair samples from 1 long-distance migrant (eastern red bat [Lasiurus borealis]) and 3 regional migrants (Indiana bat [Myotis sodalis], northern long-eared bat [M. septentrionalis], and little brown bat [M. lucifugus]) captured during the reproductive period (pregnancy and lactation) when bats are resident. LAT explained more of the variation in δDh than δDp derived from either of the GIS-based models, although 1 model of δDp performed better for some species. We found significant intraspecific differences in the relationships between δDh and LAT and between δDh and estimates of δDp derived from Bowen et al. (δDpB) for L. borealis, and significant variation in the regression equations of δDh and LAT and δDh and δDp among species for adult females and adult males. Stable hydrogen isotope analysis may be a valuable tool for studying migratory connectivity in bats, but significant intra- and interspecific variation in δDh values suggests that pooling across sex and age categories and use of surrogate species should be avoided. [ABSTRACT FROM AUTHOR]

Declining bat populations and increasing demands on forest resources have prompted researchers to investigate tree roost selection of forest bats. Few studies, however, have investigated different spatial scales and landscape pattern as criteria for selection of tree roosts. In 1999 and 2000, we radiotracked 23 eastern red bats (Lasiurus borealis) to 64 day roosts. Using univariate and multivariate comparisons, we tested roost tree variables with random tree data at 3 circular spatial scales: roost tree, plot, and landscape. We found 15 variables that were entered in a stepwise discriminant analysis to best differentiate between the roost and random samples; 11 (73.3%) were landscape variables measured with a geographic information system. On average (x̄ ± SE), red bats roosted in deciduous trees (42.0 ± 2.1 cm dbh) that were located in plots with more (3.1 ± 0.1 m²) basal area, higher (84.0 ± 1.3) percentage of canopy closure, and lower (27.2 ± 2.2) percentage of groundcover than random plots. At the landscape scale (by percent magnitude), red bat buffers (1,000-m-radius circle) had significantly less development (81.6%), less feeding operations (70.4%), more deciduous (52.9%) and pine forest (63.8%), and fewer local roads (5.4%) but more trails (94.1%), open water (61.4%), wetland areas (80.4%), and stream areas (63.1%) than random buffers. Red bat roost trees were significantly closer (χ² = 22.0088, df = 1, P ≤ 0.001) to trails (106.2 ± 13.3 m) than to streams (279.4 ± 28.5 m). Our results suggest that red bats in our study area select roosts in mature riparian forests near trails, open water, and wetlands. The high percentage of landscape values in the discriminant analysis lends support to using landscape metrics as an investigative technique of resource selection. We recommend that managers consider landscape factors when protecting red bat day-roost habitat. [ABSTRACT FROM AUTHOR]

Eastern red bats (Lasiurus borealis) have been found to overwinter in areas that can experience severe fluctuations in temperature. We examined the red bat's use of winter roosts in southwest Missouri, USA, for 2 winters (20033005). We found tree roosts in eastern red cedars (Juniperus virginiana) and hardwoods. Tree roost sites were located on the south side of trees, and we found roost trees on south-facing slopes. Roost sites occurred more frequently in the location with least canopy cover. Bats switched from tree roosts to leaf litter roosts when ambient temperatures approached or fell below freezing. We found habitat characteristics and aspect to be determining factors in the selection of leaf litter roosts. Management of overwintering red bats requires a diverse forest structure, including canopy gaps, stand density variation, and leaf-bearing trees, including oaks (Quercus spp.). [ABSTRACT FROM AUTHOR]

Our objective was to determine rates of rabies infection in bats submitted to the Indiana State Department of Health (ISDH) between species, over time, and in normally behaving bats. Those are important questions for public health reasons and also for protection of bats. Bats were tested by ISDH by using the immunofluorescent method. We tested 8,262 bats for rabies at the ISDH from 1966 to 2003, of which 445 (5.4%) tested positive. The 2 most common species, the big brown bat (Eptesicus fuscus; n = 5,584; 173 [3.1%] rabid), and the red bat (Lasiurus borealis; n = 1,512; 169 [11.2%] rabid), accounted for 85.9% of submissions. We found the highest rates of rabies in the hoary bat (L. cinereus; 54 of 178 [30.3%] rabid) and eastern pipistrelle (Pipistrellus subflavus; 41 of 314 [13.1%] rabid). Rates of rabies in other species ranged from 3.7% in the silver-haired bat (Lasionycteris noctivagans) to zero in Indiana myotis (Myotis sodalis) and evening bats (Nycticeius humeralis). The above data were mostly for incapacitated bats that people found sick or dead rather than normally behaving bets. None of 259 normally behaving big brown bats examined from areas where rabid bets had occurred were rabid. Levels of rabies in the big brown bat remained relatively stable throughout the study period with peak activity during late summer and fall. [ABSTRACT FROM AUTHOR]

Changes in structure and arrangement of forests may influence the distribution of bat communities by affecting roosting and foraging habitat. Using Anabat bat detectors, we determined presence of bat species at 316 sample plots in southeastern Missouri, USA, through qualitative identification of echolocation calls collected. We used maximum-likelihood estimation techniques incorporating detection probabilities into estimation of site occupancy by species of bats. We compared a priori models at 2 geographic scales using information theoretic methods. At the local-site scale, eastern pipistrelle (Pipistrellus subflavus) and red bat (Lasiurus borealis) occupancy was most influenced by structural characteristics of forested areas, whereas Indiana bats (Myotis sodalis) were influenced most by density of large-diameter snags that could provide roosting habitat. At the landscape scale, occupancy of Indiana bats was directly related to amount of nonforested land cover. Northern long-eared bat (M. septentrionalis) occupancy was inversely related to edge. These data describe implications of forest fragmentation and provide information that can be used when integrating forest-management practices into bat conservation. [ABSTRACT FROM AUTHOR]