Behavior Of Bats Research Articles

Establishment of a Captive Cave Nectar Bat (Eonycteris spelaea) Breeding Colony in Singapore.

Bats are known natural reservoirs of several highly pathogenic zoonotic viruses, including Hendra virus, Nipah virus, rabies virus, SARS-like coronaviruses, and suspected ancestral reservoirs of SARS-CoV-2 responsible for the ongoing COVID-19 pandemic. The capacity to survive infections of highly pathogenic agents without severe disease, together with many other unique features, makes bats an ideal animal model for studying the regulation of infection, cancer, and longevity, which is likely to translate into human health outcomes. A key factor that limits bat research is lack of breeding bat colonies. To address this need, a captive bat colony was established in Singapore from 19 wild-caught local cave nectar bats. The bats were screened for specific pathogens before the start of captive breeding. Custom-made cages and an optimized diet inclusive of Wombaroo dietary formula, liquid diet, and supplement of fruits enabled the bats to breed prolifically in our facility. Cages are washed daily and disinfected once every fortnight. Bats are observed daily to detect any sick bat or abnormal behavior. In addition, bats undergo a thorough health check once every 3 to 4 mo to check on their overall wellbeing, perform sampling, and document any potential pregnancy. The current colony houses over 80 bats that are successfully breeding, providing a valuable resource for research in Singapore and overseas.

Attraction to conspecific social-calls in a migratory, solitary, foliage-roosting bat (Lasiurus cinereus)

As a migratory, cryptic, foliage-roosting bat with a mostly solitary roosting behavior we have an incomplete understanding of the social behavior of the hoary bat, Lasiurus cinereus. In this species most social interactions between conspecifics are thought to involve mating behavior or territorial disputes. Developing a more complete understanding of the social behavior of this species would provide critical insight to address conservation challenges including high fatality rates from wind turbines during the period of fall migration. We tested the response of hoary bats to conspecific social call playback during the spring and fall migration to: (1) test whether conspecific social call broadcasting attracts or repels individual bats; (2) examine whether there are seasonal differences in these responses; (3) describe the structure and variation of recorded social calls; and (4) test whether conspecific social call playback can increase capture success. Hoary bats were attracted to social call broadcasting during both the spring and fall migration. Hoary bats produced social calls during the spring and fall migration, and when only males were present, suggesting a social function not associated with mating. While calls were variable in frequency and length, social calls tended to be a consistent upsloping shape. Attraction to social calls suggests social interactions not associated with mating behavior in hoary bats, and this technique proved successful as an acoustic lure to aid in capture and study of this elusive species.

Factor analysis of the Zaporizhzhia wind park impact on bats based on the index of their activity and dynamics of species diversity

Based on the studies in the period of 2010-2021, there was obtained some information on the behavior of bats and their species composition at the Zaporizhia wind park in the Zaporizhia Region, Ukraine. In the study area, there was established the presence of 10 species of bats belonging to 7 genera. The most complete results were obtained in 2019, when 4 field research methods were used, 28 expedition trips were carried out and 4177 bat signals were recorded. In total, the information on 43938 bat signals was collected in 2010-2021. The total operating time of the ultrasonic detectors was 4565 hours. There were calculated indices of the voice activity of bats for three research methods by seasons, different functional zones and phases of the annual cycle of animals. Surveys on transects with the geo-position of each recorded signal made it possible to characterize the distribution of bats over the territory of the wind farm, and the use of the Kernel Density tool allowed to differentiate the wind farm site of the Zaporizhia wind park into the zones that are conditionally safe for bats and high-risk zones. There have been determined the periods of the year and time periods of night activity, in which it is advisable to use measures to minimize the negative impact. Using international and own experience, there have been proposed methods for repelling bats away from the wind turbines.

Airport noise disturbs foraging behavior of Japanese pipistrelle bats.

The expansion of anthropogenic noise poses an emerging threat to the survival and reproductive success of various organisms. Previous investigations have focused on the detrimental effects of anthropogenic noise on the foraging behavior in some terrestrial and aquatic animals. Nevertheless, the role of airport noise in impairing foraging activities of most wild animals has been neglected. Here, we aimed to assess whether foraging behavior in free‐living Japanese pipistrelle bats (Pipistrellus abramus) can be disturbed by airport noise. We used audio recording to monitor foraging activities of bats at 11 sites around the runway of a municipal airport. We quantified noise level and spectra, aircraft activity, habitat type, nightly temperature, wind speed, and moon phase for each site. The analysis revealed that noise level and aircraft activity were significant negative predictors for the number of bat passes and feeding buzzes around the runway, even after controlling for the effects of other environmental factors. There was no marked spectral overlap between bat echolocation pulses and airport noise in the presence and absence of low‐flying aircraft. The spectro‐temporal parameters of echolocation vocalizations emitted by bats were dependent on noise level, aircraft activity, and habitat type. These results provide correlative evidence that airport noise can reduce foraging activities of wild pipistrelle bats. Our findings add to the current knowledge of adverse impacts of airport noise on foraging bats in artificial ecosystems and provide a basis for further research on the mechanisms behind noise pollution near airports.

ROADWAY-ASSOCIATED CULVERTS MAY SERVE AS A TRANSMISSION CORRIDOR FOR PSEUDOGYMNOASCUS DESTRUCTANS AND WHITE-NOSE SYNDROME IN THE COASTAL PLAINS AND COASTAL REGION OF GEORGIA, USA.

White-nose syndrome (WNS) is a disease among hibernating North American bats caused by the psychrophilic fungus Pseudogymnoascus destructans. Since its discovery in New York state, US, in 2006, and as of 2020, WNS has rapidly spread to 34 American states and seven Canadian provinces, causing precipitous declines of native bat populations across North America. The rapid spread of this fungal pathogen has been facilitated by the social behavior of bats, as well as the ability of subterranean hibernacula to support a favorable environment for P. destructans, and is probably exacerbated by anthropogenic transmission events. Although many bat species roost in natural cave environments, bats also selectively use diverse structures for hibernacula. Certain areas of the US lack caves, forcing bats to select different winter roosting environments. Bats have been observed using roadway-associated structures, such as bridges and culverts, for roosting, especially in regions that lack natural cave environments. However, the potential for P. destructans transmission in such roadway-associated structures requires further investigation. Understanding potential pathogen transmission in these widely used anthropogenic structures is crucial to disease management and preventing further declines of imperiled bat populations. Our study investigated these structures as potential pathogen transmission corridors by surveying the use of these structures by Perimyotis subflavus and other susceptible bat populations and by measuring their temperature. The results suggest the environments of roadway-associated culverts are thermally conducive to the proliferation of P. destructans-even in regions with mild winters-and the development of WNS in susceptible bat populations. It is apparent these roadway-associated structures have the potential to spread P. destructans and exacerbate the effect of WNS on susceptible bat populations.

Discriminating predation attempt outcomes during natural foraging using the post-buzz pause in the Japanese large-footed bat, Myotis macrodactylus

ABSTRACTBats emit a series of echolocation calls with an increasing repetition rate (the terminal buzz) when attempting to capture prey. This is often used as an acoustic indicator of prey-capture attempts. However, because it is directly linked to foraging efficiency, predation success is a more useful measure than predation attempts in ecological research. The characteristics of echolocation calls that consistently signify predation success across different situations have not been identified. Owing to additional influencing factors, identification of these characteristics is particularly challenging for wild bats foraging in their natural environment compared with those in flight chambers. This study documented the natural foraging behavior of wild Japanese large-footed bats (Myotis macrodactylus) using synchronized acoustic and video recordings. From the video recordings, we could assign 137 attacks to three outcome categories: prey captured (51.8%), prey dropped (29.2%) and failed attempt (19%). Based on previous indications from laboratory studies that the length of the silent interval following the terminal buzz (post-buzz pause) might reflect the prey-capture outcome, we compared post-buzz pause durations among categories of attack outcomes. The post-buzz pause was longest in the case of successful capture, suggesting that the length of the post-buzz pause is a useful acoustic indicator of predation success during natural foraging in M. macrodactylus. Our finding will advance the study of bat foraging behavior using acoustic data, including estimations of foraging efficiency and analyses of feeding habitat quality.

Optimum Design of a Novel Bio-Inspired Bat Robot

Inspired by the agility, high efficiency, and low noise of bat flight, we propose the design of an unoccupied aerial vehicle (UAV) that can mimic the flight behaviors of bats. By adjusting the wing flapping and morphing during both upstroke and downstroke phases, bats achieve aerodynamic performance that generates sufficient lift and thrust forces for diverse maneuvers. To mimic bat morphology in a robot, we use a multi-objective optimization method to determine the Cartesian positions of the wings, and the elbow angle, which in turn influences the wing area. Our goal is to minimize the differences between the biological bat’s limb trajectories (elbow angles and Cartesian trajectories) and those of the robot. Due to the complex dimensionality of bats, a mathematical tool: Principal Component Analysis, is combined with the weighted sum method in the optimization algorithm. Via simulation, we observed overall agreement of elbow angles between the kinematics of a biological bat (Pteropodidae: <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Cynopterus brachyotis</i> ) and the robot, along with a reasonable match on the folding and flapping angles. The proposed method provides a straightforward and robust approach for the optimization of bat-inspired robots.

Perception at the extreme: Adaptive vocal-motor behavior of bats at high speed flight and in groups

In order to successfully navigate through their environments without collisions at often high speeds, bats rely on two things: successful reconstruction of their environment from returning echoes and motor outputs in response to intermittent sensory information. This depends on the coordination between sensory input and locomotive output. Many bats regularly form dense aggregations in the wild and fly at speeds exceeding 100 km/h, likely posing significant sensorimotor challenges. We recorded the echolocation and flight behavior of wild frequency-modulated (FM) bats as they exited and returned to their cave roost to understand how bats coordinate flight and echolocation when faced with sensory challenges. We found that when exiting the roost in groups, many bats coordinate flight behavior and wingbeat movement with nearby conspecifics, but based on heading delays, this coordination is likely not driven by acoustic cues and instead may be guided by aerodynamic cues. During high-speed roost re-entry, bats modify echolocation signals consistent with increasing object discrimination as they approach the roost, yet adjustments in flight behavior do not coincide with the reception of echoes, suggesting that bats may be combining information from multiple pulses or senses to plan their flight path. [Work supported by ONR N000141612478 and NSF-IIBR-1916850.]

Positively selected genes in the hoary bat (Lasiurus cinereus) lineage: prominence of thymus expression, immune and metabolic function, and regions of ancient synteny.

BackgroundBats of the genus Lasiurus occur throughout the Americas and have diversified into at least 20 species among three subgenera. The hoary bat (Lasiurus cinereus) is highly migratory and ranges farther across North America than any other wild mammal. Despite the ecological importance of this species as a major insect predator, and the particular susceptibility of lasiurine bats to wind turbine strikes, our understanding of hoary bat ecology, physiology, and behavior remains poor.MethodsTo better understand adaptive evolution in this lineage, we used whole-genome sequencing to identify protein-coding sequence and explore signatures of positive selection. Gene models were predicted with Maker and compared to seven well-annotated and phylogenetically representative species. Evolutionary rate analysis was performed with PAML.ResultsOf 9,447 single-copy orthologous groups that met evaluation criteria, 150 genes had a significant excess of nonsynonymous substitutions along the L. cinereus branch (P < 0.001 after manual review of alignments). Selected genes as a group had biased expression, most strongly in thymus tissue. We identified 23 selected genes with reported immune functions as well as a divergent paralog of Steep1 within suborder Yangochiroptera. Seventeen genes had roles in lipid and glucose metabolic pathways, partially overlapping with 15 mitochondrion-associated genes; these adaptations may reflect the metabolic challenges of hibernation, long-distance migration, and seasonal variation in prey abundance. The genomic distribution of positively selected genes differed significantly from background expectation by discrete Kolmogorov–Smirnov test (P < 0.001). Remarkably, the top three physical clusters all coincided with islands of conserved synteny predating Mammalia, the largest of which shares synteny with the human cat-eye critical region (CECR) on 22q11. This observation coupled with the expansion of a novel Tbx1-like gene family may indicate evolutionary innovation during pharyngeal arch development: both the CECR and Tbx1 cause dosage-dependent congenital abnormalities in thymus, heart, and head, and craniodysmorphy is associated with human orthologs of other positively selected genes as well.

Analysis of echolocation behavior of bats in \u201cecho space\u201d using acoustic simulation

BackgroundEcholocating bats use echo information to perceive space, control their behavior, and adjust flight navigation strategies in various environments. However, the echolocation behavior of bats, including echo information, has not been thoroughly investigated as it is technically difficult to measure all the echoes that reach the bats during flight, even with the conventional telemetry microphones currently in use. Therefore, we attempted to reproduce the echoes received at the location of bats during flight by combining acoustic simulation and behavioral experiments with acoustic measurements. By using acoustic simulation, echoes can be reproduced as temporal waveforms (including diffracted waves and multiple reflections), and detailed echo analysis is possible even in complex obstacle environments.ResultsWe visualized the spatiotemporal changes in the echo incidence points detected by bats during flight, which enabled us to investigate the “echo space” revealed through echolocation for the first time. We then hypothesized that by observing the differences in the “echo space” before and after spatial learning, the bats’ attentional position would change. To test this hypothesis, we examined how the distribution of visualized echoes concentrated at the obstacle edges after the bats became more familiar with their environment. The echo incidence points appeared near the edge even when the pulse direction was not toward the edge. Furthermore, it was found that the echo direction correlated with the turn rate of the bat’s flight path, revealing for the first time the relationship between the echo direction and the bat’s flight path.ConclusionsWe were able to clarify for the first time how echoes space affects echolocation behavior in bats by combining acoustic simulations and behavioral experiments.

Can acoustic recordings of cave-exiting bats in winter estimate bat abundance in hibernacula?

Many bat species in North America face precarious futures due to white-nose syndrome and wind energy development. These threats, and others, make it imperative to monitor long-term population fluctuations of bats. Counting hibernating bats in caves estimates abundance of these cave-dwelling mammals, and such counts can be used to understand population fluctuations across time. Passive acoustic monitoring can capture large amounts of long-term data that are standardized, scalable, and reproducible; these data can also be archived for future analyses. Little work has been done, however, assessing the relationship between recorded acoustic data from bats that arouse from torpor during hibernation and fly out of caves and number of bats counted in hibernacula. We acoustically monitored and counted two species of bats in 9 hibernacula from November to March 2011 to 2018. We hypothesized that acoustic data recorded from Townsend’s big-eared bats (Corynorhinus townsendii) and western small-footed myotis (Myotis ciliolabrum) exiting hibernacula could be used to estimate abundance of those species in hibernacula. Over seven years, we conducted 29 hibernacula surveys and simultaneously set passive acoustic detectors during winter when those surveys were conducted. Acoustic monitors recorded for 1,063 nights. Detectors recorded 2,459 files of Townsend’s big-eared bats and 9,094 files of western small-footed myotis. Across all years and hibernacula, mean number of Townsend’s big-eared bats counted in a cave was 96; mean number of western small-footed myotis counted in a cave was 7. For Townsend’s big-eared bats, the top model held 43% of model weight and included the variables bat activity (i.e., mean number of Anabat files/night) and cave. For western small-footed myotis, the top model held 55% of model weight and contained the variable bat activity. Mean number of acoustic recordings of bats flying out of a cave across a winter was positively related to number of hibernating bats counted in a cave in a year for western small-footed myotis—with greater variability for estimates with a larger number of acoustic files recorded of bats flying out of caves; for Townsend’s big-eared bats that relationship held for 2 caves with > 90 individuals. Our results indicate that researchers can use passive acoustic data as an index of abundance of bats hibernating in caves in temperate climate zones. Additionally, our data indicate that researchers can acoustically detect hibernating western small-footed myotis even when these bats are not observed during hibernacula surveys. This monitoring can minimize the potential effect of researchers on the behavior of bats, facilitate long-term monitoring, and reduce the number of occasions that biologists enter caves to count bats.

An Observation of Spring Mating in Silver-Haired Bats (Lasionycteris noctivagans)

The mating behavior of North American tree bats (Lasiurus spp. and Lasionycteris noctivagans) is not well understood. The majority of records suggest that this group of species mates during the autumn migratory period and that females store sperm throughout the winter before resuming the reproductive cycle in spring. On 16 May 2019, while mist-netting in Bernalillo County, New Mexico, USA, we observed a male and female silver-haired bat (Lasionycteris noctivagans) copulating on the ground. Both individuals were captured and processed to obtain further details on reproductive status. To our knowledge this is the first published record of a silver-haired bat copulation event, and its occurrence during the spring migratory period challenges long-held assumptions about the reproductive cycle of the species and tree bats in general.

Winter bat activity: The role of wetlands as food and drinking reservoirs under climate change

Bat arousals during hibernation are related to rises in environmental temperature, body water loss and increasing body heat. Therefore, bats either hibernate in cold places or migrate to areas with mild winters to find water and insects to intake. During winter, insects are relatively abundant in wetlands with mild climates when low temperatures hamper insect activity in other places.However, the role of wetlands to sustain winter bat activity has never been fully assessed. To further understand bat behaviour during hibernation, we evaluated how the weather influenced hibernating bats, assessed the temperature threshold that increased bat arousals, and discussed how winter temperatures could affect bat activity under future climate change scenarios.The effects of weather and landscape composition on winter bat activity were assessed by acoustically sampling four different habitats (wetlands, rice paddies, urban areas and salt marshes) in the Ebro Delta (Spain).Our results show one of the highest winter bat foraging activities ever reported, with significantly higher activity in wetlands and urban areas. Most importantly, we found a substantial increase in bat activity triggered when nocturnal temperatures reached ca. 11 °C. By contrasting historical weather datasets, we show that, since the 1940s, there has been an increase by ca. 1.5 °C in winter maximum temperatures and a 180% increase in the number of nights with mean temperatures above 11 °C in the Ebro Delta.Temperature trends suggest that in 60–80 years, winter months will reach average temperatures of 11 °C (except maybe in January), which suggest a potential coming interruption or disappearance of bat hibernation in coastal Mediterranean habitats. This study highlights the significant role of wetlands in bat conservation under a climate change scenario as these humid areas represent one of the few remaining winter foraging habitats.

Optimized Feature Selection in Software Product Lines using Discrete Bat Algorithm

Software Product Lines (SPLs) are one of the ways to develop software products by increasing productivity and reducing cost and time in the software development process. In SPLs, each product has many features and it is necessary to consider the optimal and custom features of the products. In fact, selecting key features in SPLs is a challenging process. Feature selection in SPLs is an optimization problem and an NP-Hard problem. One way to select a feature is to use meta-heuristic algorithms modeled on nature, i.e., Bat Algorithm. By modeling bat behavior in prey hunting, a suitable meta-innovative algorithm is considered. This algorithm has important advantages that make it more accurate than conventional methods such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) algorithm. In this paper, to select software product features, idol binary algorithm and artificial neural network are used to identify important features of software products that reduce production costs and time. The experiments in MATLAB software and datasets related to software production lines show that the rate of reduction of target performance error or feature selection cost in software production lines in the proposed method has decreased by 64.17% with increasing population.

Hawaiian hoary bat responses to habitat, season, and non‐native insectivore suppression

AbstractHabitat loss and non‐native species are 2 of the most important factors that influence native species persistence and behaviors globally. The insectivorous Hawaiian hoary bat (Lasiurus semotus) is the only extant terrestrial mammal native to the Hawaiian Islands. Non‐native invasive insectivore species, which are potential competitors of bats for prey, may influence hoary bat behavior. The goal of this study was to determine how small‐scale suppression of invasive insectivores (rodents, ants, and yellowjacket wasps [Vespula pensylvanica]) influenced bat activity in grasslands and woodlands. We measured bat activity as a function of the number of distinct minutes in a night containing bat echolocations (bat call minutes) at 20 experimental plots (each 2.25 ha) in a dryland ecosystem on Hawaiʻi Island, November 2016–January 2018. We included 3 predictor variables: vegetation type (woodland, grassland), season (bat reproductive cycle periods: lactation, mating, pre‐pregnancy, and pregnancy), and insectivore treatment type (ant suppressed, yellowjacket wasp suppressed, rodent suppressed, combined ant+wasp+rodent suppressed, and no treatment). Bat activity was associated with all 3 predictors using a negative binomial generalized linear model. Bat call minutes and feeding buzzes were twice as high in woodlands than in the grasslands (2.4 and 2.3 times as high, respectively). Bat activity was slightly lower (0.47 bat call min/night fewer) in plots receiving the combined ant + wasp + rodent treatment compared to all other treatment plots. Feeding buzzes did not differ significantly among treatments. Mean activity was lowest during lactation (mid‐Jun–Aug). Although woodlands appear particularly important for the Hawaiian hoary bat, small‐scale bat activity and foraging do not appear to be strongly affected by resource competition with the invasive insectivores in this study.

Energy saving in day-roosting female Myotis emarginatus during reproduction (Chiroptera: Vespertilionidae)

From May to June 2012, we studied the behaviour of day-roosting reproductive female Geoffroy’s bats in a maternity roost in eastern Burgenland (Austria) which is under surveillance from 2011 till to date. By using a remote-controlled infrared-illuminated video camera, we conducted six weekly sessions of direct observation and instantaneous scan sampling, each lasting 16 hours. Based on a total of 384 sampling sessions, we quantified the amount of time adult females spent in the activities resting, alert, grooming and relocating during pregnancy and lactation. Ambient and roost temperatures were recorded hourly, the numbers of individuals returning to the roost in the mornings were registered constantly by using an infrared light barrier. Over the entire study period, all bats arriving in the maternity roost in the morning formed immediately a single huddling cluster. As a rule, this cluster was large, multilayered, three-dimensional and tight. It did not change in size and form until the onset of pre-emergence activities. It consisted of an interior part in which about 50% of all bats roosted and the periphery consisting of those bats which had not succeeded in entering the interior. Over the entire diurnal stay in the roost, resting – which causes the least energy output – was the predominant behaviour of all roost mates. Significant differences were found, however, in the amount of time allocated to some activities by bats occupying different positions in the cluster. While bats in the interior of the cluster spent the estimated 90–95% of the entire day-roosting period resting, bats on the periphery spent only 57–73% resting. The average percentage of time allocated by peripheral bats to grooming decreased from 27% in the first week to 19–13% in the following weeks of pregnancy and stayed at 16% during the two weeks of lactation. The mean percentages of being alert and of relocating ranged between 7–10% and 4–7%, respectively. During the last two weeks of pregnancy and the two weeks of lactation, roost temperatures, daily colony size and reproductive states did not influence the huddling behaviour significantly. However, activities performer in the first and second week were probably influenced by unrest due to colony formation after the return from hibernation (week 1) and by cold ambient temperatures during the week 2. Our study supports the hypothesis that the short duration and notable timing of reproduction typical for Myotis emarginatus (Spitzenberger &amp; Weiss 2020) is achieved by maximal energy saving through continuous huddling in a large, three-dimensional, multilayered and tight cluster over both the entire day-roosting and entire reproductive period, differences in the behaviours of bats located in the interior and on the periphery of the cluster and lack of social interactions between roost mates.

Engineering Verification of Ultrasonic Frequency Adjustment Behavior of bats

Engineering Verification of Ultrasonic Frequency Adjustment Behavior of bats

Small Mammals of Tekai Tembeling Forest Reserve (TTFR), Jerantut, Pahang, Peninsular Malaysia

Despite the increasing numbers of hydro-dam worldwide, only a handful of studies evaluated their impacts on biodiversity especially terrestrial small mammals. This survey aimed to provide an updated checklist and diversity status of small mammals inhabiting the Tekai-Tembeling Forest Reserve (TTFR), an area that has been extensively logged for the next phase of construction of dam. To elucidate further the species assemblages and diversity of small mammals within TTFR, a comparison was made to a nearby forest, Ulu Jelai Forest Reserve (UJFR), which was also has been logged for the development of Telom Dam. 10 days survey conducted in March 2018 by using cage-trapping and mist-netting techniques, successfully recorded a total of 27 species (Shannon Index (H’) = 3.11) in TTFR and 23 species (H’=2.62) in UJFR. Most of these species in TTFR were bats (56 individuals representing 22 species), rodents (three species representing four individuals) and squirrels (two species representing three individuals). Insectivorous bat species, Narrow-winged Pipistrelle (Pipistrellus cf. stenopterus), are the most abundance in TTFR mainly because insectivorous bats behavior that forage understory in a lowland forest and some of these bats is known to forage in groups. Results from this study indicated that richness and diversity of small mammal’s species assemblages appear to decline in TTFR at which this can be associated to less sampling approaches due to the seasonal impact (rainy season) and habitat disturbance or habitat changes resulted from extensive logging activity. A good mitigation measures should be conducted immediately to prevent elimination species at the study area.

Bat behavior around double-track electrified railways

Bat behavior around double-track electrified railways

Methods for assessing artificial thermal refuges: Spatiotemporal analysis more informative than averages

1Thermal refuges are widely used by animals of all taxonomic groups and are critical to survival in severe weather. 2Human activities are reducing the availability of natural refuges; consequently, artificial refuges are used as conservation management tools, particularly for bats. 3Published box evaluations are generally incomplete, omitting thermal physiology and relevant thermal properties. 4Here, we compare methods for evaluating the potential utility of bat box designs for bats and present a graphical spatiotemporal method that provides more complete information. 5For illustration, we compare the original to three modified versions of the “rocket box” style bat box. 6Box internal temperatures and generalized thermal physiology models are combined in two suitability indices appropriate to the mother, and to pups. 7Results revealed that daily and seasonal averages of these indices obscured important processes and showed insignificant differences among bat box design modifications. 8In contrast, graphical analysis highlighted the presence and spatiotemporal structure of significant differences among boxes, which were most evident in sunny weather. 9Differences among boxes were sensitive to assumptions about bat thermal physiology and behavior. 10We found that an external water jacket mitigated temperature extremes and extended favorable temperatures into the night, which could enhance pup development while the mothers foraged. 11Further experiments are needed to evaluate the relation between metabolic heating by box occupants and thermal conditions within bat boxes.