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Native predators provide undervalued pest suppression services to agriculture. Studies of pest consumption by insectivorous bats tend to focus upon single species in large, centralized colonies, while bats dispersed in small groups within the agricultural matrix often go unnoticed. Pecan trees, Carya illinoinensis, and the destructive pecan nut casebearer (PNC) moth, Acrobasis nuxvorella, comprise a tightly linked host&ndash, parasite system in a widespread agroecosystem native to North America. Here we use a quantitative polymerase chain reaction (qPCR) assay of fecal DNA to document predation on PNC moths by an assemblage of sympatric bat species across episodic peaks in PNC abundance. Although five species of bats consume PNC moths, greater predation by a solitary tree-roosting bat (eastern red bat, Lasiurus borealis) than other species is suggested by a higher frequency of PNC occurrence and quantity of PNC gene copies in fecal samples. Consumption of PNC by bats during all documented peaks in moth activity suggests that predation pressure occurs throughout the PNC season. Our results highlight the need to consider multi-species assemblages and different foraging strategies when assessing pest suppression services, particularly in agroforestry or tree crops. Assessing the diet of only common or easily captured species limits our ability to accurately document pest consumption by bats.

Landscape complexity influences patterns of animal dispersal, which in turn may affect both gene flow and the spread of pathogens. White-nose syndrome (WNS) is an introduced fungal disease that has spread rapidly throughout eastern North America, causing massive mortality in bat populations. We tested for a relationship between the population genetic structure of the most common host, the little brown myotis (Myotis lucifugus), and the geographic spread of WNS to date by evaluating logistic regression models of WNS risk among hibernating colonies in eastern North America. We hypothesized that risk of WNS to susceptible host colonies should increase with both geographic proximity and genetic similarity, reflecting historical connectivity, to infected colonies. Consistent with this hypothesis, inclusion of genetic distance between infected and susceptible colonies significantly improved models of disease spread, capturing heterogeneity in the spatial expansion of WNS despite low levels of genetic differentiation among eastern populations. Expanding our genetic analysis to the continental range of little brown myotis reveals strongly contrasting patterns of population structure between eastern and western North America. Genetic structure increases markedly moving westward into the northern Great Plains, beyond the current distribution of WNS. In western North America, genetic differentiation of geographically proximate populations often exceeds levels observed across the entire eastern region, suggesting infrequent and/or locally restricted dispersal, and thus relatively limited opportunities for pathogen introduction in western North America. Taken together, our analyses suggest a possibly slower future rate of spread of the WNS pathogen, at least as mediated by little brown myotis.

In response to seasonal variation in energy availability and thermal environment, physiological and endocrine mechanisms have evolved in temperate zone animals. Seasonal changes in hormone activity affect metabolism, body temperature, and reproductive activity. We examined the seasonal regulatory role of hormones on basal metabolic rate (BMR) and regulatory nonshivering thermogenesis (RNST) in 98 female and 17 male adult Eptesicus fuscus (big brown bat). We measured BMR, RNST, and plasma levels of thyroid hormone (T3), leptin, and cortisol in bats captured in maternity colonies in eastern Massachusetts from May to August (from arousal from the hibernation phase to the prehibernation phase). We hypothesized that all three hormones are seasonally primarily metabolic hormones and secondarily thermogenic hormones. In males, only BMR significantly changed seasonally. In females, all five variables significantly changed seasonally. The seasonal pattern of plasma leptin and cortisol levels correlated with the seasonal pattern of BMR, with an initial increase followed by a decrease, suggesting that leptin and cortisol are primarily metabolic hormones. The seasonal pattern of plasma T3 levels generally paralleled the basic seasonal pattern of RNST, with both increasing at the second half of the season, suggesting that T3 is primarily a thermogenic hormone. The observed decrease in plasma leptin levels may be necessary to allow for the observed seasonal decrease in BMR, with the similar cortisol pattern important for leptin regulation. While T3 is needed to maintain BMR, it may play a more critical role in the seasonal regulation of RNST than of BMR.

The insectivorous bat Myotis lucifugus typically apportions the night into two foraging periods separated by an interval of night roosting. During this interval, many bats occupy roosts that are used exclusively at night and are spatially separate from maternity roosts. The proportion of the night which bats spend roosting, and thus the proportion spent foraging, vary both daily and seasonally in relation to the reproductive condition of the bats, prey density, and ambient temperature. A single, continuous night roosting period is observed during pregnancy. During lactation, females return to maternity roosts between foraging bouts, and night roosts are used only briefly and sporadically. Maximum use of night roosts occurs in late summer after young become volant. Superimposed upon these seasonal trends is day-to-day variation in the bats' nightly time budget. Long night roosting periods and short foraging periods are associated with cool nights and low prey density. This behavioral response may minimize energetic losses during periods of food scarcity.

International audience; 1. Undersampling is commonplace in biodiversity surveys of species-rich tropical assemblages in which rare taxa abound, with possible repercussions for our ability to implement surveys and monitoring programmes in a cost-effective way. 2. We investigated the consequences of information loss due to species undersampling (missing subsets of species from the full species pool) in tropical bat surveys for the emerging patterns of species richness (SR) and compositional variation across sites. 3. For 27 bat assemblage data sets from across the tropics, we used correlations between original data sets and subsets with different numbers of species deleted either at random, or according to their rarity in the assemblage, to assess to what extent patterns in SR and composition in data subsets are congruent with those in the initial data set. We then examined to what degree high sample representativeness (r ≥ 0 8) was influenced by biogeographic region, sampling method, sampling effort or structural assemblage characteristics. 4. For SR, correlations between random subsets and original data sets were strong (r ≥ 0 8) with moderate (ca. 20%) species loss. Bias associated with information loss was greater for species composition; on average ca. 90% of species in random subsets had to be retained to adequately capture among-site variation. For non random subsets, removing only the rarest species (on average c. 10% of the full data set) yielded strong correlations (r > 0 95) for both SR and composition. Eliminating greater proportions of rare species resulted in weaker correlations and large variation in the magnitude of observed correlations among data sets. 5. Species subsets that comprised ca. 85% of the original set can be considered reliable surrogates, capable of adequately revealing patterns of SR and temporal or spatial turnover in many tropical bat assemblages. Our analyses thus demonstrate the potential as well as limitations for reducing survey effort and streamlining sampling protocols, and consequently for increasing the cost-effectiveness in tropical bat surveys or monitoring programmes. The dependence of the performance of species subsets on structural assemblage characteristics (total assemblage abundance, proportion of rare species), however, underscores the importance of adaptive monitoring schemes and of establishing surrogate performance on a site by site basis based on pilot surveys.

The nature of forest structure plays an important role in the study of foraging behaviors of bats. In this study, we demonstrate a new combined methodology that uses both thermal imaging technology and a ground-based LiDAR system to record and reconstruct Eptesicus fuscus (big brown bats) flight trajectories in three-dimensional (3-D) space. The combination of the two 3-D datasets provided a fine-scale reconstruction of the flight characteristics adjacent to and within the forests. A 3-D forest reconstruction, assembled from nine Echidna Validation Instrument LiDAR scans over the 1 ha site area, provided the essential environmental variables for the study of bat foraging behaviors, such as the canopy height, terrain, location of the obstacles, and canopy openness at a bat roosting and maternity site in Petersham, Massachusetts. Flight trajectories of 24 bats were recorded over the 25 m × 37.5 m region within the LiDAR forest reconstruction area. The trajectories were reconstructed using imaging data from ...

Summary Frugivory among bats (Chiroptera) has evolved independently in the New and Old World tropics: within the families Phyllostomidae and Pteropodidae, respectively. Bats from both families rely primarily on olfaction for the location of fruits. However, the influence of bats on the evolution of fruit scent is almost completely unknown. Using the genus Ficus as a model, the aims of this study were to explore the chemical composition of fruit scent in relation to two contrasting seed dispersal syndromes in Panama and Malaysia and to assess the influence of fruit scent on the foraging behaviour of neo- and palaeotropical fruit-eating bats (Artibeus jamaicensis and Cynopterus brachyotis, respectively). Two hypotheses were tested: (i) variation in fruit scent, between bat- and bird-dispersed figs, is independent of phylogeny and (ii) Old and New World fruit bats, which have evolved independently in each hemisphere, share the same olfactory preferences with respect to fruit scent. The fruit scents of bat- and bird-dispersed fig species were sampled in the field, using dynamic headspace adsorption techniques. New and Old World fruit bats were then captured and tested on natural fig fruit scents from both hemispheres. Chemical analyses, using gas chromatography (GC) and GC/mass spectrometry (MS), revealed a broad overlap in scent compounds between bat-dispersed fig species from both hemispheres. Their fruit scents were dominated by monoterpenes, which contrary to phylogenetic predictions, were completely absent from bird-dispersed species from both regions. The fruit scents of bat-dispersed figs were highly attractive to neotropical bats (A. jamaicensis) in behavioural experiments, whereas those of bird-dispersed figs were completely rejected. Neotropical bats (A. jamaicensis) exhibited a significant preference for fig fruit scents dominated by monoterpenes, independent of the geographical origin of the scent. Palaeotropical bats (C. brachyotis), by contrast, rejected monoterpene-rich fruit scents from the Neotropics. In a cluster analysis (which included additional, published data from the literature), the fruit scents of bat-dispersed figs were clumped by subgenus, with the exception of palaeotropical figs of the subgenus Sycomorus. C. brachyotis, from Malaysia, was the only fruit bat species that significantly preferred the fruit scents of Sycomorus figs that contained no monoterpenes.

In Central Amazonia, large mammals create water-filled puddles when consuming soil. These mineral licks are visited by pregnant and lactating frugivorous bats; possibly for two reasons. Frugivorous bats could supplement their mineral-depleted fruit diet by drinking salty water, or they could buffer dietary plant secondary compounds by consuming soil. We analysed bat fruits from Ecuador and showed that they are depleted in elemental concentrations (Na, K, P) compared with similar fruits collected from Costa Rica, where no mineral licks occur (n = 32). Analyses of water from Ecuador revealed that water samples from six mineral licks contained more physiologically relevant elements (Na, K, Mg, Ca) than four samples from river and stream water control sites (Mann–WhitneyU-test). In support of the nutrient supplement hypothesis, we observed bats drinking mineral-enriched water at these licks (video observation). Furthermore, blood collected from 68 bats differed in composition with respect to physiologically relevant minerals (Na, K, Mg, Fe) from that of frugivorous bats captured at control sites. To test whether frugivorous bats also consumed clay for detoxification, we checked for soil tracer elements in 31 faecal samples. Soil tracers are insoluble in water and, thus, are not included in a strict fruit diet. Bats from mineral licks showed higher aluminium soil tracer concentrations in their faeces than bat species that never visit licks, suggesting that frugivorous bats take up clay material at mineral licks. Our results provide evidence that frugivorous bats ingest soluble mineral nutrients and insoluble soil by consuming soil-enriched water at mineral licks, thus supporting the hypothesis that frugivorous bats of western Amazonia may derive a dual benefit from drinking water from mineral licks.

The performance capabilities of flying animals reflect the interplay of biomechanical and physiological constraints and evolutionary innovation. Of the two extant groups of vertebrates that are capable of powered flight, birds are thought to fly more efficiently and faster than bats. However, fast-flying bat species that are adapted for flight in open airspace are similar in wing shape and appear to be similar in flight dynamics to fast-flying birds that exploit the same aerial niche. Here, we investigate flight behaviour in seven free-flying Brazilian free-tailed bats (Tadarida brasiliensis) and report that the maximum ground speeds achieved exceed speeds previously documented for any bat. Regional wind modelling indicates that bats adjusted flight speeds in response to winds by flying more slowly as wind support increased and flying faster when confronted with crosswinds, as demonstrated for insects, birds and other bats. Increased frequency of pauses in wing beats at faster speeds suggests that flap-gliding assists the bats' rapid flight. Our results suggest that flight performance in bats has been underappreciated and that functional differences in the flight abilities of birds and bats require re-evaluation.

This article provides a brief overview and a few glimpses of how various factors influence the reproductive energetics of terrestrial reptiles, birds, and mammals. The amount of energy allocated to various phases of reproduction (courtship and mating, incubation, gestation, lactation, parental care, and the pre- and postfledging or postlactational periods) is, in part, influenced by the type of reproduction (oviparity vs. vivaparity), different types of mating system (monogamy, polygyny, and polyandry), rates of posthatching and postnatal growth, competitive interactions with members of the same or different species, and extrinsic factors such as habitat quality, food availability, and climate. In general, costs of courtship and mating are higher for males that typically compete for females by developing elaborate structures or behaviors used in courtship display to show females that they are fit and by defending either mating territories or females. The energy investment that male vertebrates make in the production of gametes is relatively small compared with that made by females, and female reptiles and birds typically invest more in egg production (both size and number) than do female mammals. Apart from the production of a relatively large number of eggs, few reptiles exhibit maternal care once the young hatch. In contrast, birds and mammals often invest extensively in their young once they hatch or are born. Female birds allocate large amounts of energy to brooding and feeding their young until they have reached or exceed adult size. Some bird species invest further in their offspring by tutoring them once they have fledged. In contrast, mammals typically produce a relatively small number of eggs that are fertilized internally, the fetus develops in the uterus that is protected from environmental extremes, young are born alive, and females nurse their young with milk for variable periods of time and in many species may provide extended care to their offspring. Among males, courtship and mating are the most energetically expensive activities in reptiles, birds, and mammals. The production of nutrient- and energy-rich eggs is the most energetically expensive phase of reproduction in female reptiles. Production and incubation of eggs and feeding of nestlings comprise the most energetically expensive phase of reproduction in female birds. Lactation is the most energetically expensive period of reproduction in female mammals. In addition to the physiological costs of reproduction, we describe how some mammals may expend energy to provide behavioral forms of parental care (including paternal and alloparental care); however field data quantifying these activities are severely lacking, so their costs are rarely included in studies on reproductive energetics.

Acoustic signals are important in maintaining group cohesion, particularly in highly mobile species. For these signals to facilitate group cohesion, individuals must be able to recognize, and respond to, calls emitted by group members. In this study, we document the use and recognition of complementary contact calls in Spix’s disc-winged bat (Thyroptera tricolor), a species known to form very stable social groups despite using an extremely ephemeral roosting resource. This bat uses 2 sets of calls: “inquiry,” which are emitted by flying bats that are seeking roosts or group mates, and “response,” which are produced in reply to an inquiry call by individuals that have already located a roost. Here, we test if bats are capable of discriminating between the inquiry and response calls of group and nongroup mates using playback experiments. Results show that flying bats can discriminate between the inquiry and response calls emitted by group and nongroup members and can maintain contact preferentially with the former. Roosting bats, however, exhibited no preference for group over nongroup members and thus responded indiscriminately. We argue that differences in how individuals respond to calls from group and nongroup members may be partly attributed to the costs associated with flight and the potential benefits of recruiting roost mates. Committee for Research and Exploration of the National Geographic Society/[8973-11]//Estados Unidos UCR::Sedes Regionales::Sede del Sur

In the absence of visual cues, chemical signals are especially important for nocturnal mammals such as bats, because they facilitate individual recognition, communication, and mate selection. In a recent study, it was reported that adult males of the Curacaoan long-nosed bat, Leptonycteris curasoae, develop an odoriferous dorsal patch during the short mating season. It was postulated that dorsal patches signal health condition to females, and that females are preferentially attracted to the odor of males with dorsal patches. The chemical characterization of the dorsal patch is key to understanding its implications in chemical communication in a sexual context. In the present study, organic compounds collected from dorsal patches of males of L. curasoae from northwestern Venezuela were extracted using solid-phase micro-extraction (SPME) techniques and tentatively identified using GC-MS (Gas Chromatography-Mass Spectrometry). Nineteen compounds were present in 75% or more of the patches examined: 3-methyl-2...

Aeroecology is an emerging scientific discipline that integrates atmospheric science, Earth science, geography, ecology, computer science, computational biology, and engineering to further the understanding of biological patterns and processes. The unifying concept underlying this new transdisciplinary field of study is a focus on the planetary boundary layer and lower free atmosphere (i.e., the aerosphere), and the diversity of airborne organisms that inhabit and depend on the aerosphere for their existence. Here, we focus on the role of radars and radar networks in aeroecological studies. Radar systems scanning the atmosphere are primarily used to monitor weather conditions and track the location and movements of aircraft. However, radar echoes regularly contain signals from other sources, such as airborne birds, bats, and arthropods. We briefly discuss how radar observations can be and have been used to study a variety of airborne organisms and examine some of the many potential benefits likely to arise from radar aeroecology for meteorological and biological research over a wide range of spatial and temporal scales. Radar systems are becoming increasingly sophisticated with the advent of innovative signal processing and dual-polarimetric capabilities. These capabilities should be better harnessed to promote both meteorological and aeroecological research and to explore the interface between these two broad disciplines. We strongly encourage close collaboration among meteorologists, radar scientists, biologists, and others toward developing radar products that will contribute to a better understanding of airborne fauna.

The impact of ecology and social organization on genetic structure at landscape spatial scales, where gene dynamics shape evolution as well as determine susceptibility to habitat fragmentation, is poorly understood. Attempts to assess these effects must take into account the potentially confounding effects of history. We used microsatellites to compare genetic structure in seven bat species with contrasting patterns of roosting ecology and social organization, all of which are codistributed in an ancient forest habitat that has been exceptionally buffered from radical habitat shifts. Over one thousand individuals were captured at foraging sites and genotyped at polymorphic microsatellite loci. Analyses of spatially explicit genotype data revealed interspecies differences in the extent of movement and gene flow and genetic structure across continuous intact forest. Highest positive genetic structure was observed in tree-roosting taxa that roost either alone or in small groups. By comparison, a complete absence of genetic autocorrelation was noted in the cave-roosting colonial species across the study area. Our results thus reveal measurable interspecies differences in the natural limits of gene flow in an unmodified habitat, which we attribute to contrasting roosting ecology and social organization. The consequences of ecology and behaviour for gene flow have important implications for conservation. In particular, tree-roosting species characterized by lower vagility and thus gene flow will be disproportionally impacted by landscape-scale forest clearance and habitat fragmentation, which are prevalent in the study region. Our method also highlights the usefulness of rapid sampling of foraging bats for assaying genetic structure, particularly where roosting sites are not always known.

Projected changes in climate for the northeastern USA over the next 100 years include a reduction in the depth and duration of the winter snowpack, which could affect soil temperatures and frost regimes. We conducted a snow-removal experiment in a northern hardwood forest at the Hubbard Brook Experimental Forest in central New Hampshire over 2 years to induce soil freezing and evaluate its effect on the abundance, richness, and diversity of soil arthropods during the growing season. Snow removal at the beginning of winter increased the depth and duration of soil frost, decreased soil temperatures, and led to a reduced abundance of some arthropod taxa, including Araneae (reduced by 57%; P=0.0001), Pseudoscorpionida (75%; P

White-nose syndrome (WNS) is a newly emergent disease that potentially threatens all temperate bat species. A recently identified fungus, Geomyces destructans, is the most likely causative agent of this disease. Until 2009, WNS and G. destructans were exclusively known from North America, but recent studies have confirmed this fungus is also present in Europe. We assembled an international WNS consortium of 67 scientists from 29 countries and identified the most important research and conservation priorities to assess the risk of WNS to European bats. Here, we review what is known about WNS and G. destructans and detail the conservation and research recommendations aimed at understanding and containing this emerging infectious disease.

Although a considerable amount of information has accumulated about oligosaccharides in the milk and colostrum of representatives of various mammalian orders, nothing is so far known concerning these sugars in the milk of any bat species (order Chiroptera). In this study, we determined that the following oligosaccharides occur in milk of the island flying fox, Pteropus hypomelanus (Chiroptera: Pteropidae): Gal(α1-3)Gal(β1-4)Glc (isoglobotriose), Gal(β1-4)GlcNAc(β1-3)Gal(β1-4)Glc (lacto-N-neotetraose), Gal(β1-4)GlcNAc(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-neohexaose) and Neu5Gc(α2-3)Gal(β1-4)Glc (3'-NGc-SL). However, lactose was found to be the dominant saccharide in this milk, as in most eutherian mammals. The biologic importance of oligosaccharides in Chiropteran milks warrants further study.

The seasonal dorsal patch of males of the Curacaoan long-nosed bat, Leptonycteris curasoae, which exhibits variability in size, shape, and chemical complexity, is a trait associated with courtship and mating in this species. This recently discovered structure develops exclusively during the mating season that occurs once a year between November and December in populations of L. curasoae from northern Venezuela. Although the dorsal patch that develops in males has unique chemical characteristics possibly involved in female attraction, we suggest that this trait also sends distinct visual cues regarding the health status of males. We evaluated the postulated association between dorsal patch shape (symmetry) and ectoparasite load (streblid batflies) in males of L. curasoae. To do so, we quantified the shape of dorsal patches on males to test the hypothesis that streblid load was related to this variable. Over 2,000 streblid batflies of two different species (Nycterophilia coxata and Trichobius sphaeronotus) ...

White-nose syndrome (WNS) is a disease responsible for unprecedented mortality in hibernating bats. First observed in a New York cave in 2006, mortality associated with WNS rapidly appeared in hibernacula across the northeastern United States. We used yearly presence–absence data on WNS-related mortality among hibernating bat colonies in the Northeast to determine factors influencing its spread. We evaluated hazard models to test hypotheses about the association between the timing of mortality and colony-level covariates, such as distance from the first WNS-affected site, colony size, species diversity, species composition and type of hibernaculum (cave or mine). Distance to origin and colony size had the greatest effects on WNS hazard over the range of observations; the type of hibernaculum and species composition had weaker effects. The distance effect showed a temporal decrease in magnitude, consistent with the pattern of an expanding epizootic. Large, cave-dwelling bat colonies with high proportions of Myotis lucifugus or other species that seek humid microclimates tended to experience early mortality. Our results suggest that the timing of mortality from WNS is largely dependent on colony location, and large colonies tend to be first in an area to experience high mortality associated with WNS.

Myotis lucifugus populations in Northeastern US are being decimated by a fungal disease. Since almost nothing is known about the immune system of bats, we are characterizing the immunoglobulin genes of bats. We show that M. lucifugus has a diverse V(H) gene repertoire comprised of five of the seven human V(H) gene families and an estimated 236V(H)3 genes. 95% of these germline VH3 genes differ in FR3. A comparison of 67 expressed V(H)3 genes with 75 germline V(H)3 genes revealed a mutation frequency similar to fetal piglets never exposed to environmental antigens. Analysis of CDR3 regions identified at least 13 putative J(H) segments and a large D(H) repertoire. The low mutation frequency, highly diverse V(H), D(H), and J(H) germline repertoire suggests that this species may rely more on combinatorial and junctional diversity than on somatic hypermutation raising questions about the ability of M. lucifugus to respond rapidly to emerging pathogens.

Summary 1. Species richness is a state variable of some interest in monitoring programmes but raw species counts are often biased due to imperfect species detectability. Therefore, monitoring programmes should quantify detectability for target taxa to assess whether it varies over temporal or spatial scales. We assessed the potential for tropical bat monitoring programmes to reliably estimate trends in species richness. 2. Using data from 25 bat assemblages from the Old and New World tropics, we estimated detectability for all species in an assemblage (mean proportion of species detected per sampling plot) and for individual species (species-specific detectability). We further assessed how these estimates of detectability were affected by external sources of variation relating to time, space, survey effort and biological traits. 3. The mean proportion of species detected across 96 sampling plots was estimated at 0AE76 (range 0AE57–1AE00) and was significantly greater for phytophagous than for animalivorous species. Species

Ecosystem services are the benefits obtained from the environment that increase human well-being. Economic valuation is conducted by measuring the human welfare gains or losses that result from changes in the provision of ecosystem services. Bats have long been postulated to play important roles in arthropod suppression, seed dispersal, and pollination; however, only recently have these ecosystem services begun to be thoroughly evaluated. Here, we review the available literature on the ecological and economic impact of ecosystem services provided by bats. We describe dietary preferences, foraging behaviors, adaptations, and phylogenetic histories of insectivorous, frugivorous, and nectarivorous bats worldwide in the context of their respective ecosystem services. For each trophic ensemble, we discuss the consequences of these ecological interactions on both natural and agricultural systems. Throughout this review, we highlight the research needed to fully determine the ecosystem services in question. Finally, we provide a comprehensive overview of economic valuation of ecosystem services. Unfortunately, few studies estimating the economic value of ecosystem services provided by bats have been conducted to date; however, we outline a framework that could be used in future studies to more fully address this question. Consumptive goods provided by bats, such as food and guano, are often exchanged in markets where the market price indicates an economic value. Nonmarket valuation methods can be used to estimate the economic value of nonconsumptive services, including inputs to agricultural production and recreational activities. Information on the ecological and economic value of ecosystem services provided by bats can be used to inform decisions regarding where and when to protect or restore bat populations and associated habitats, as well as to improve public perception of bats.

One of the most widely distributed bats in the New World, the big brown bat (Eptesicus fuscus) exhibits well-documented geographic variation in morphology and life history traits, suggesting the potential for significant phylogeographic structure as well as adaptive differentiation among populations. In a pattern broadly consistent with morphologically defined subspecies, we found deeply divergent mitochondrial lineages restricted to different geographic regions. In contrast, sequence data from two nuclear loci suggest a general lack of regional genetic structure except for peripheral populations in the Caribbean and Mexico/South America. Coalescent analyses suggest that the striking difference in population structure between genomes cannot be attributed solely to different rates of lineage sorting, but is likely due to male-mediated gene flow homogenizing nuclear genetic diversity across most of the continental range. Despite this ongoing gene flow, selection has apparently been effective in producing and maintaining adaptive differentiation among populations, while strong female site fidelity, maintained over the course of millions of years, has produced remarkably deep divergence among geographically isolated matrilines. Our results highlight the importance of evaluating multiple genetic markers for a more complete understanding of population structure and history.

Brazilian free-tailed bats (Tadarida brasiliensis) emerge from cave roosts in dense columns in which adjacent bats are separated by only small distances. We describe and quantify variation in the structure of echolocation calls produced by these emerging bats and determine if call structure changes in relation to the rate of emergence measured using thermal infrared imaging. We recorded emergence calls at 2 roosts, 1 housing approximately 200,000 bats and the other approximately 17,000 bats. We found that Brazilian free-tailed bats emit distinct frequency-modulated (FMstart) and constant frequency (CFstart) calls during emergence that are significantly different from echolocation calls they emit while foraging. We propose that these calls provide different information for orientation within the emergence column. CFstart calls are very similar to social calls used by Brazilian free-tailed bats, suggesting 2 potential functions for this call type. The structure of both the FMstart and CFstart calls were not related to the number of bats emerging from a roost, although significant structural differences existed between sites. The differences between sites could be associated with the spacing of bats during emergence, because bats appeared to form tighter columns at the larger roost colony compared to the smaller colony. DOI: 10.1644/09-MAMM-A-302.1.

Threats to and from Bats Bats appear to be able to host an assortment of alarming pathogens, which, if they do not extirpate the bats, have implications for human health (see the Perspective by Daszak ). For example, exposure to bats is the main source of human rabies in the Americas. But rabies is not generally transmitted among people; humans are a dead end for the virus. Streicker et al. (p. 676 , see the cover) show that rabies virus lineages tend to be specific for bat lineages. It seems that although rabies viruses have the potential for rapid evolution, this property alone is not enough to overcome genetic barriers, which inhibit the onward transmission of rabies virus into a new species. White-nose syndrome, an exotic fungal infection of bats, has, over the past 3 years, spread from upstate New York to West Virginia, killing on average 70% of the animals in a hibernating colony. The infection makes bats restless over winter when they should be dormant, which makes them exhaust their fat reserves, resulting in the death of over a million bats. Frick et al. (p. 679 ) have analyzed population data collected on bats in the northeastern United States for the past 30 years and show that, mainly owing to white-nose syndrome, the once abundant little brown bat is heading for regional extinction in the next 16 years or so. This scale of loss of an insectivorous mammal is expected to have repercussions for ecosystem integrity and for the economic costs of agricultural pest control.

The Brazilian free-tailed bat (Tadarida brasiliensis) experiences challenging thermal conditions while roosting in hot caves, flying during warm daylight conditions, and foraging at cool high altitudes. Using thermal infrared cameras, we identified hot spots along the flanks of free-ranging Brazilian free-tailed bats, ventral to the extended wings. These hot spots are absent in syntopic cave myotis (Myotis velifer), a species that forages over relatively short distances, and does not engage in long-distance migration. We hypothesized that the hot spots, or “radiators,” on Brazilian free-tailed bats may be adaptations for migration, particularly in this long-distance, high-flying species. We examined the vasculature of radiators on Brazilian free-tailed bats with transillumination to characterize the unique arrangements of arteries and veins that are positioned perpendicular to the body in the proximal region of the wing. We hypothesized that these radiators aid in maintaining heat balance by flushing the uninsulated thermal window with warm blood, thereby dissipating heat while bats are flying under warm conditions, but shunting blood away and conserving heat when they are flying in cooler air at high altitudes. We also examined fluid-preserved specimens representing 122 species from 15 of 18 chiropteran families and radiators appeared present only in species in the family Molossidae, including both sedentary and migratory species and subspecies. Thus, the radiator appears to be a unique trait that may facilitate energy balance and water balance during sustained dispersal, foraging, and long-distance migration.

The short-nosed fruit bat Cynopterus sphinx (Chiroptera : Pteropodidae) constructs shelters by severing stems of the curtain creeper, Vernonia scandens, and stems and leaves of the mast tree, Polyalthia longifolia, creating partially enclosed cavities (stem tents) in which to roost. Our observations indicate that the construction and maintenance of stem tents are primarily, if not exclusively, the behaviour of single males. A stem tent is formed in V. scandens when a single male C. sphinx severs up to 300 small- to medium-sized stems creating a partially flattened, bell-shaped cavity, and in P. longifolia when a male severs a few medium- to small-sized branches and many leaf petioles, creating an entry/exit portal and space in which to roost. A tent constructed in V. scandens is completed in approximately 30 d, whereas one in P. longifolia is completed in about 50 d. Stem-tent construction takes place mostly at night, but some stem chewing occurs in late afternoon. At night a stem tent is occupied by a single male, whereas females are usually absent. During the day the number of bats occupying completed tents is highly variable, ranging from two to 19 females (and their pups) and a single adult male. Tent construction is annually bimodal, which corresponds to a biannual breeding season. A dominant male sometimes deposits saliva on branches inside his tent cavity and actively defends this space from intrusions by other males. Both behaviours suggest forms of scent marking and territorial display. Our observations indicate that dominant males construct tents, recruit females and then defend the tents (and their female occupants) for the purpose of gaining reproductive access. The variance in harem group size indicates that some tent-making males are more successful than others in recruiting females.

Previous studies have investigated rabies virus (RABV) epizootiology in Brazilian free-tailed bats (Tadarida brasiliensis) in natural cave roosts. However, little is known about geographic variation in RABV exposure, or if the use of man-made roosts by this species affects enzootic RABV infection dynamics within colonies. We sampled rabies viral neutralizing antibodies in bats at three bridge and three cave roosts at multiple time points during the reproductive season to investigate temporal and roost variation in RABV exposure. We report seropositive bats in all age and sex classes with minimal geographic variation in RABV seroprevalence among Brazilian free-tailed bat colonies in south-central Texas. While roost type was not a significant predictor of RABV seroprevalence, it was significantly associated with seasonal fluctuations, suggesting patterns of exposure that differ between roosts. Temporal patterns suggest increased RABV seroprevalence after parturition in cave colonies, potentially related to an influx of susceptible young, in contrast to more uniform seroprevalence in bridge colonies. This study highlights the importance of life history and roost ecology in understanding patterns of RABV seroprevalence in colonies of the Brazilian free-tailed bat.

Phyllostomid bats form some of the most speciose mammalian assemblages known, with more than 70 species estimated to co-occur on one site. These species encompass a dietary spectrum that ranges across several trophic levels, and many show morphological specializations for their dietary behaviour (e.g., long tongues in nectar-feeding bats). However, previously reported diets have varied among studies including assignments of species to feeding ensembles. In this study we present data that demonstrate that phyllostomid bats are opportunistic omnivores despite their specializations. We analyzed the diet of 67 phyllostomid bat species from the Neotropics based on both fecal analyses and nitrogen isotope ratios in wing tissue and found that most species complemented their primary diet with nutrients from many different food sources. From these new dietary data, we were unable to distinguish meaningful feeding ensembles of species based on diet. Thus, we argue that interspecific competition is not res...

Dietary proteins are considered crucial for growth and maintenance in mammals, but many fruit-eating mammals feed largely on a protein-poor diet. In the Chir-optera, frugivory has evolved twice, in the Old World Pteropodidae and in the New World Phyllostomidae, especially the Stenodermatinae. Recent studies based onthe analysis of nitrogen isotope ratios (d 15 N) suggest that phyllostomids feed to varying degrees on arthropods to meet their nitrogen (N) requirements. ArthropodfeedinghasrarelybeenobservedinPteropodidae.Thus,weaskedwhetherpteropodidsmeettheirNrequirementsbyfeedingexclusivelyonplantmatter.Wepredictedthattissuefrompteropodidwingmembranes shouldbe depletedin 15 Nrelativeto thoseofobligateinsectivorousrhinolophoid, vespertilionid oremballonurid bats,ifpteropodidsacquireproteinsexclusivelyfromfruits,leavesornectar.Wefoundthatd 15 Ninpteropodidsweresignificantlylowerthaninobligateinsectivorousbats.Inaddition, mean d 15 N of Old World pteropodids was similar to that of obligate frugivorous stenodermatines of the New World tropics. We infer from these data thatpteropodids are predominantly phytophagous bats. From a nutritional perspective, pteropodids and stenodermatines are very similar, suggesting that they shareconvergent physiological adaptations to compensate for the lack of dietary nitrogen.Key words: diet; insectivory; isotopes; nitrogen balance; Pteropodidae; Phyllostomidae.

The colony of Brazilian free-tailed bats (Tadarida brasiliensis) at Carlsbad Cavern, New Mexico, is a wellknown example of this highly gregarious and conspicuous species in North America. For nearly a century researchers have tried to estimate the size of this colony, but different census methods and lack of repeatability have resulted in questionable estimates that have given rise to poorly understood but highly popularized, longterm population trends for this migratory species. In this study we present accurate seasonal estimates of colony size based on a recently developed census method—thermal infrared imaging and computer vision analysis. The size of the colony was estimated several times monthly from March through October 2005. Our estimates range from 67,602 to 793,838 bats, values that are orders of magnitude lower than the largest historic estimates. Consecutive estimates of nightly emergences show fluctuations of as many as 291,000 individuals, indicating that colony composition is considerably more dynamic than previously thought. Our results, combined with a quantitative analysis of emergence behavior, question the validity of early historic estimates that millions of bats once roosted in this cave and suggest that the long-term pattern of decline reported for this species might not be as severe as currently thought. DOI: 10.1644/08-MAMM-A-391R.1.

Billions of animals migrate each year. To successfully reach their destination, migrants must have evolved an appropriate genetic program and suitable developmental, morphological, physiological, biomechanical, behavioral, and life-history traits. Moreover, they must interact successfully with biotic and abiotic factors in their environment. Migration therefore provides an excellent model system in which to address several of the “grand challenges” in organismal biology. Previous research on migration, however, has often focused on a single aspect of the phenomenon, largely due to methodological, geographical, or financial constraints. Integrative migration biology asks ‘big questions’ such as how, when, where, and why animals migrate, which can be answered by examining the process from multiple ecological and evolutionary perspectives, incorporating multifaceted knowledge from various other scientific disciplines, and using new technologies and modeling approaches, all within the context of an annual cycle. Adopting an integrative research strategy will provide a better understanding of the interactions between biological levels of organization, of what role migrants play in disease transmission, and of how to conserve migrants and the habitats upon which they depend.

Recent technological innovation has opened new avenues in migration research - for instance, by allowing individual migratory animals to be followed over great distances and long periods of time, as well as by recording physiological information. Here, we focus on how technology - specifically applied to bird migration - has advanced our knowledge of migratory connectivity, and the behavior, demography, ecology, and physiology of migrants. Anticipating the invention of new and smaller tracking devices, in addition to the ways that technologies may be combined to measure and record the behavior of migratory animals, we also summarize major conceptual questions that can only be addressed once innovative, cutting-edge instrumentation becomes available.

As the human population continues to expand, increased encroachment on natural landscapes and wildlife habitats is expected. Organisms able to acclimate to human-altered environments should have a selective advantage over those unable to do so. Over the past two decades, bats have increasingly begun to roost and raise offspring in spaces beneath pre-cast concrete bridges. Few studies have examined the health or fitness of individuals living in these anthropogenic sites. In the present study, we examined birth size and postnatal growth, as surrogates of reproductive success, in Brazilian free-tailed bat pups born at a natural and a human-made roost. Based on putative stress-related conditions (noise from vehicular traffic, chemical pollutants and a modified social environment) present at bridges, we predicted that bats at these sites would have reduced reproductive success. Contrary to our prediction, pups born at a bridge site were on average heavier and larger at birth and grew faster than those born at a cave site. Also, both birth size and growth rates of pups differ between years. We attribute observed differences to a combination of roost-related conditions (i.e. roost temperature and proximity to foraging areas), climate and maternal effects with larger mothers raising larger pups. Thus, some bridge roosts, at least in the short term, are suitable, and in some cases may provide better conditions, for raising young bat pups than cave roosts.

Flexible behaviors permit gregarious animals to exploit spatially and temporally favorable conditions for reproduction. Evening emergences of Brazilian free-tailed bats (Tadarida brasiliensis) in south-central Texas were recorded to determine changes in colony dynamics and to evaluate hypotheses associated with predator avoidance and seasonal energy demands. In 2007, median parturition date was 18 June and lactation lasted about 54 days. Juveniles commenced flight after 41 days, then continued to suckle for 2 weeks before being weaned. Onset of evening emergence was correlated with sunset, beginning, on average, 11.8 min after sunset (95% confidence interval = 7.1, 16.6), which is later than reported in previous studies. Pregnant females emerged later than their roost mates, consistent with a predator avoidance hypothesis. Lactating females emerged after sunset, but earlier than other bats, consistent with the hypothesis that this is a period of high energy demand. Juveniles emerged later than adult females while they continued to be suckled, but emerged earlier as they matured and were weaned, suggesting a trade-off between predator avoidance and energy demands. Our observations indicate that evening emergence behavior of T. brasiliensis varies with environmental cues but is mediated by the energetic demands of reproduction.

White-nose syndrome (WNS) is an emerging disease causing massive mortality of hibernating bats in the northeastern United States. At hibernacula, bats affected with WNS typically exhibit growth of a white psychrophylic fungus (Geomyces destructans) on the nose, wings and ears; many individuals seem to prematurely die of starvation owing to depleted fat reserves. Conspicuous scarring and necrosis of the wings on WNS-affected bats that survive hibernation may have lasting consequences for survival and reproductive success during the active season. We monitored two maternity colonies of little brown myotis, Myotis lucifugus, in Massachusetts and New Hampshire from 14 May to 8 August 2008 to assess body conditions after expected exposure to WNS over the previous winter. We developed a 4-point wing damage index (WDI = 0 to 3) to assess the incidence and severity of wing damage in the months following emergence from hibernation. Severe wing damage was observed up to 4 June and moderate damage was observed through 9 July. Light wing damage was observed on both adult and juvenile bats throughout the study period, but was not exclusively attributed to WNS. The most severe wing damage was associated with a lower body mass index which may reflect reduced foraging success. Overall, reproductive rate was 85.1% in 2008; slightly lower than reported in previous studies. The incidence, timing, and geographic range of wing damage observed on little brown myotis in 2008 correspond to the occurrence of WNS at hibernacula. Monitoring wing conditions of affected and healthy bats will be important tool for assessing the spread of this disease and for establishing baseline data for unaffected bats. The simple scale we propose should be useful for monitoring wing conditions in any bat species.

Adult males of the long-nosed bat (Leptonycteris curasoae) produce odoriferous ‘‘sebaceous’’ secretions in the interscapular region (dorsal patch), exclusively during the mating season (November–December). These dorsal patches might play a role in mate selection by L. curasoae in northern Venezuela. We evaluated differences between body traits of males with and without dorsal patches to determine whether these structures could be used by females as indicators of male quality, examined whether the size of the dorsal patch shows a relationship with other body traits during the mating season, and investigated the physical and behavioral development of dorsal patches. Thirty-seven percent of all males sampled (n 5 99) showed conspicuous dorsal patches during the mating season in November and December. Males with conspicuous dorsal patches had larger testes, smaller body masses, lower body condition indices, and lower ectoparasite loads than males without dorsal patches. Larger testes and lower ectoparasite loads suggest that the dorsal patch could be signaling male quality and readiness for mating. A typical dorsal patch covered approximately 1.7 cm 2 of a male’s interscapular region, but size of this structure did not vary with any of the body traits examined. We describe a novel, stereotypic behavior performed by male L. curasoae, which we call ‘‘smearing behavior,’’ and suggest that this is associated with development of the dorsal patch because males appear to smear different body fluids onto this patch. We further suggest that sebaceous secretions in the interscapular region would not be the determining factor in dorsal patch development.

The ability to measure body composition is critical for studying the physiological ecology of animals. This is particularly true for small mammals that have a high metabolic rate. We evaluated a nondestructive method of body composition analysis that would allow accurate assessment of body fat, body water, and lean mass. We used total body electrical conductivity (TOBEC) to estimate body composition in the little brown myotis (Myotis lucifugus). In a sample of 46 individuals, TOBEC was both accurate and precise in estimating total body water and lean mass but was less effective at estimating total body fat. Mass-independent or whole-body compartments (i.e., total body water, total body fat, lean dry mass, and lean body mass) were more accurately estimated than mass-dependent or mass-specific body composition compartments (i.e., water content, fat index, and % lean dry mass). The TOBEC measurements we made using an SA-3000 analyzer were influenced by extremes in body temperature, as well as by aluminum and incoloy wing bands. Our study also presents a new method of restraint especially suited for small mammals and birds that increases precision of TOBEC measurements. This study shows that TOBEC is a potentially valuable tool for studying changes in body composition of small mammals and may provide insight into the physiological impacts of various life history stages such as postnatal growth, reproduction, and hibernation.