As many as 17 subspecies are currently recognized for the lesser false vampire, Megaderma spasma along its wide distributional range, from India to Southeast Asia. Cytogenetic studies have been so far restricted to specimens from only four geographical regions, namely Malaysia, Thailand, China and the Philippines. We examined the karyotypes of M. spasma medium from Peninsular Malaysia and M. s. trifolium from Malaysian Borneo with conventional and molecular cytogenetic techniques, using whole chromosome painting probes from the vespertilionid Myotis myotis and the hipposiderid Aselliscus stoliczkanus. Both Megaderma subspecies showed the same diploid chromosome number, 2n = 38, but differed concerning interstitial heterochromatic segments and number and shape of heterochromatic B chromosomes. Comparison with published data revealed that the Bornean specimens' karyotype best resembled the chromosomal set of the Chinese specimen. In contrast, a single male specimen from Malaysian Borneo showed a different karyotype (2n = 40) without B chromosomes and interstitial heterochromatin, indicating that it may represent a cryptic, yet unknown Megaderma species.

Geoffroy's bat, Myotis emarginatus, is the only species of the African clade of the genus Myotis distributed in the south-western part of the Palaearctic. Due to its extensive distribution range, stretching across several ecologic zones from the European and African Mediterranean, Central Europe, through the Levant and Caucasus to West Turkestan and south-eastern Middle East, this bat is traditionally considered to be a variable and polytypic species. While one subspecies was recognized in Europe and North Africa, up to four subspecies were reported from the Asian part of the species range. Nevertheless, the systematic positions of different populations and the validity of particular taxa remained unclear. Our aim was to revise the phylogenetic status of M. emarginatus and, for the first time, genetically analyse samples from the Asian part of its range to provide new insight into its intraspecific variation. We analysed sequences of two mitochondrial and three nuclear markers from more than 130 samples from all parts of the species range, together with sequences from other species from the African clade of the genus Myotis. According to the previous morphometric results of body and skull dimensions, M. emarginatus can be divided into two groups of populations: the small-sized and more variable bats of Europe, the Maghreb and Levant; and the large-sized bats of the rest of the Asian range. This division was well supported by mitochondrial genes, which separated two main lineages within the species: the western lineage from Europe, the Maghreb and Levant; and the eastern lineage from the eastern Middle East and West Turkestan. Both mitochondrial lineages were further divided into two sublineages: the western lineage to sublineages from the Holy Land and the rest of the Mediterranean range; and the eastern lineage to sublineages from Oman and southern Iran, and northern Iran and West Turkestan. In contrast, the nuclear genes reconstructed only one lineage through the whole distribution range, suggesting M. emarginatus to be a monophyletic species. Nevertheless, on the basis of previously described geographical variability in morphology and the newly described mitochondrial variation, we recognize two subspecies within M. emarginatus: small-sized M. e. emarginatus distributed in the Mediterranean, western and central Europe and Levant; and large-sized M. e. desertorum in the eastern Middle East, from Oman to West Turkestan.

The Blasius's horseshoe bat (Rhinolophus blasii) shows a fragmented distribution in the European part of its range, and its populations are threatened by many human-induced factors. The status and distribution of the species in Romania are largely unknown. In recent years, regular bat surveys and monitoring have confirmed the presence of the species in north-western Romania, in Gălăşeni Cave, Pădurea Craiului Mountains, representing the northernmost distribution point of R. blasii in Europe. In our study we investigated whether this northernmost colony is genetically isolated from, or related to, larger populations in south-western Romania. A combined analysis of two mitochondrial (12S, HVII) and two nuclear (RAG2, DBY7) genetic markers was used in order to reveal possible relationships between these populations. The small number of haplotypes, the presence of shared haplotypes and overall low population structure suggest that the south-western and north-western Romanian populations are related through yet unidentified colonies of R. blasii, with continuous migration between them. Our results also indicate that the R. blasii colony from Gălăşeni Cave was established by female individuals migrating not far from their birthplace. To preserve this marginal population in a long term, conservation measures need to be strengthened and properly enforced, in parallel with the search for new R. blasii colonies in the region. To our knowledge, the present work represents the only molecular study of R. blasii in Europe.

Knowledge of Afrotropical bat diversity is hindered by hidden diversity because of inefficient sampling techniques, limited survey effort, and taxonomic description. With 90 bat species recorded, Nigeria supports almost a third of the bat diversity known to occur in Africa, yet the country remains relatively under-sampled. Southeastern Nigeria and southwestern Cameroon are predicted to be the largest of six bat diversity hotspots in Africa, with the Cameroonian side receiving more sampling effort. This area is also recognized to support hyperdiverse mammalian assemblages and endemic species. Notwithstanding, two major protected areas on the Nigerian part of this bat diversity hotspot were hitherto not sampled, raising the likelihood of discovering new country records in these conservation priority forests. We conducted an intensive survey using harp traps and mist nets in forests of Afi Mountain Wildlife Sanctuary and Cross River National Park (Okwangwo Division). We also recorded echolocation calls of captured individuals to create the first in-country call library. We captured 36 bat species of which 10 are new country records raising the number of bat species known from Nigeria to 100. Harp trap captures represented 99% of forest understory bats sampled with 15 out of 18 species caught exclusively in traps. Rarefaction curves of captures suggest near-complete sampling with harp traps but incomplete sampling with mist nets. Eight of the 10 new country records were captured exclusively in harp traps, demonstrating the value of contemporary techniques for frequently missed species — here referred to as methodological blind-spot diversity. We report the re-identification of two museum specimens that were previously identified as Rhinolophus hillorum (R. cf. hillorum) and Miniopterus inflatus (M. villiersi) thus, our captures of the true forms confirm the presence of both species in Nigeria for the first time. We also provide noteworthy taxonomic comments on other species. To improve the efficiency of future Afrotropical bat surveys we recommend the deployment of complementary trapping techniques in identified diversity hotspots, especially sites that have been under-sampled.

Knowledge of the Cambodian bat fauna has grown in recent years, although much remains to be learnt. Based on field surveys undertaken throughout the country in 2014–2020 and using morphological (external, cranial and dental characters), genetic and acoustic data, we document the first records of six bat species nationally (Rhinolophus marshalli, R. siamensis, Hipposideros halophyllus, H. lekaguli, Cassistrellus yokdonensis and Eptesicus pachyomus) and the second in-country record for an additional species (Saccolaimus saccolaimus). All of these taxa were encountered in Cambodia's understudied border regions where literature for neighbouring territories suggests future field research will likely reveal other bat species presently unknown in the country. We also comment on the distribution and conservation status of the newly documented taxa, provide a revised checklist of the 80 bat species now confirmed in Cambodia and briefly consider the prospects for future discoveries and bat conservation in the country.

We examined the effects of the level of internal ⁹⁰Sr and ¹³⁷Cs concentrations on hematological parameters of bats captured in the Chernobyl Exclusion Zone (Ukraine). In total, 68 animals of six bat species were live-monitored with measurement of the whole-body activity concentrations of the two radionuclides (⁹⁰Sr and ¹³⁷Cs) and blood sampling for further analysis. We found statistically significant positive correlations between the blood neutrophil count and whole-body ⁹⁰Sr activity concentration in individuals of Eptesicus serotinus; and between the neutrophil/lymphocyte ratio and ⁹⁰Sr concentration, and between the red blood cell (RBC) count and ¹³⁷Cs concentration in Vespertilio murinus. We did not observe any correlation between concentrations of ⁹⁰Sr and ¹³⁷Cs and hematological parameters in individuals of Pipistrellus nathusii. Moreover, none of these three species showed significant sexual (male versus female) or age (adult versus sexually immature) differences in ⁹⁰Sr and ¹³⁷Cs concentrations. Our results contribute to better knowledge and understanding of the eco-immunology of free-ranging bats in one of the most radioactively contaminated areas in the world — the Chernobyl Exclusion Zone. To our knowledge, this is the first study investigating the relationship between radionuclide contamination and hematological parameters of bats.

The western Amazon is characterized by a shortage of available minerals. Chemical analysis of food items and feces of frugivorous bats has shown that they may experience inadequate mineral intake. Assessing the inter-taxon and seasonal variations in mineral loads of wild frugivorous bats may help determine the mineral constraints in their diets. Our sampling was based on bats from the genus Carollia (n = 19 specimens) and the tribe Stenodermatini (n = 20; mainly genera Platyrrhinus and Artibeus) from highland tropical forests in Peru collected during the dry and wet seasons throughout a year. We analyzed the total concentrations of eight minerals in combined samples of liver and spleen for each bat, and compared concentrations between taxa and seasons. Our findings regarding manganese, iron, copper, zinc, and magnesium concentrations were generally consistent with those reported in the literature, while the sodium, potassium, and calcium concentrations would be the first reported in bats. We observed higher mineral concentrations in Carollia than in Stenodermatini bats, which may be linked with differences in their dietary preferences and inherent physiological characteristics. Seasonal mineral variations of frugivorous bats reported here were associated with temporal differences in the food items consumed and availability of mineral licks. Given that bats we studied come from a mineral-limited ecosystem, we suggest that Stenodermatini bats may face greater dietary limitations for sodium and potassium, and that frugivorous bats may exhibit seasonal constraints for copper and calcium. Recognition of potentially limited minerals, coupled with future studies on plant products that contain them, would be useful in the restoration programs for highland forests, which is one of the most threatened ecosystems in the Neotropics.

Understanding the factors that explain animals' diet diversity is important to comprehend niche partitioning, co-existence, biotic interactions, and the vulnerability of species populations to habitat transformation. Species body mass and their geographical range are positively related to the diversity of food items they consume and consequently with their potential ecological niche occupied. However, the relative weight of these factors to explain diet diversity in mammals is poorly known. Using Artibeina frugivorous bats as a biological model, we evaluate the importance of body mass and ecoregions occupied to explain the diet diversity of these bats. We analyzed our data using phylogenetic correlations and Bayesian statistics techniques. Our results show a stronger phylogenetic correlation between bats' diet diversity with the number of ecoregions they occupied than with their body mass. These results suggest Neotropical frugivorous bats that occupy different habitats had a major possibility to have a higher diet diversity. In addition, these results are related with the ‘bottom-up’ diet diversity hypothesis that postulates that diet diversity in frugivorous bats is related to ecosystem plant diversity.

Human-modified landscapes are often composed of small and isolated natural habitat fragments immersed in agricultural and urban matrices. Within them, ecosystem services provided by wildlife, such as pest insect suppression, may decrease or even be lost leading to a substantial increase in agricultural production costs. Pest insect suppression by bats has been identified as an essential ecosystem service but remains poorly investigated. For example, we still lack a basic understanding of the proportion of pest insects that comprises the diet of many bat species. Here, we explored the diet composition of eight Brazilian bat species (78 individuals) in a human-modified landscape through the analysis of stable carbon (¹³C) and nitrogen (¹⁵N) isotopes. Bats were categorised into guilds: open-space aerial insectivores, narrow-space gleaning frugivores, or narrow-space gleaning nectarivores. We divided the insects collected into three groups depending on their δ¹³C values: forest, mixed, and pest insects. We found that open-space insectivorous bats had the highest proportion of insects in total in their diet — consuming primarily from the forest group (56%) and the pest group (34%). Interestingly, narrow-space gleaning frugivores also consumed pest insects (almost 20%). The narrow-space gleaning nectarivores had traces of insects in their diet, yet the actual proportion was inconclusive. Even though bats were from different guilds, with diets consisting mainly of plants and insects, the δ¹⁵N indicated that they fitted to similar trophic levels, as secondary consumers. Therefore, the trophic level of nectarivorous and frugivorous bats showed a more generalist diet than previously assumed. The proportion of forest insects in the diet of open-space aerial insectivores may indicate the importance of small forest patches as food resources for wildlife such as the ones included in human-modified landscapes. The bats' contribution to this ecosystem service could improve the economic conservation value of Neotropical bats in human-modified landscapes.

While torpid, small hibernators experience negative water balance due to evaporative water loss. The use of humid hibernacula and ability to drink during periodic arousals allows most hibernators to manage this deficit over the course of a winter. Some populations of big brown bats (Eptesicus fuscus) hibernate in relatively dry rock-crevices that do not contain free standing water. We monitored the winter behaviour and physiology of one such population in the Canadian prairies. Due to the semi-arid climate, we hypothesized that these bats would experience relatively high evaporative water loss and make frequent mid-winter flights to find water. We measured serum ion concentrations and hematocrit to assess level of dehydration in bats captured during winter. We also provided a heated water tank enriched in deuterium (²H) and used stable isotope analysis to test for elevated hydrogen isotope ratios (²H/¹H; herein δ²H) in the blood of bats to determine if individuals drank from the tank. We also used passive acoustic monitoring, video surveillance, and passive integrated transponder (PIT) tags to determine if bats visited the heated water tank. We found evidence of hypertonic dehydration (elevated hematocrit and concentrations of some serum ions) in bats as winter progressed. Blood δ²H of bats was similar to that of water on the landscape, and acoustic and video surveillance did not indicate any visits by bats to the water tank. Post-arousal dehydration is not uncommon in hibernators, which agrees with our observation that the water tank did not represent a water resource, despite it being the only open (not frozen) water available. It is unknown whether bats may exploit frozen sources of water (e.g., snow) to supplement metabolic water produced from fat catabolism.

Multiple studies show that animals exhibit consistent individual differences in behavior, but they also experience short-term changes in their behavioral responses associated with seasonal events, most notably reproduction. We compare calling rates between the breeding and non-breeding seasons, and between males and females, in Spix's disk-winged bats (Thyroptera tricolor). This species performs an exchange of inquiry and response calls in a context of social coordination and these vocalizations are used by individuals to signal roost location. Our results indicate that during the breeding season all males vocalize and also emit a greater number of response calls. In females, we found that there is no significant difference in their vocal behavior during the breeding and non-breeding seasons. Even though being vocal leads to greater energy costs and risk of predation, males were more vocal and emitted more vocalizations when females are known to be ovulating. Therefore, our results suggest that response calls may not only facilitate group cohesion, as found in previous studies, but that it may also play a role in courtship.

Changes in landscape environmental characteristics may influence habitat use by bat species as well as species composition and community functional structure. Landscape features may drive the functional role variability of bat species on the ecosystems. Consequently, landscapes may change the degree of functional differentiation between species. We have evaluated the effect of pine forest monoculture and their environmental characteristics on the distribution and functional attributes of bat species. We sampled bat communities in areas with high (three sites) and low (three sites) forest land use management practices including six mist-netting locations in order to sample for bats at each site. In addition, we have also measured temperature, humidity, percentage of land use coverage (managed forest, agriculture, and native forest), and percentage of canopy openness at each site. We captured 87 bats belonging to eight species representing two families: Phyllostomidae and Vespertilionidae. For the functional analysis, we used three functional attributes to describe wing morphology: wing loading, aspect ratio, and forearm length. No significant effect of any environmental variable was observed on bat species composition. However, bat species distribution was driven by the ability associated with their functional attributes to occupy the space. Moreover, forearm length was positively correlated with forest cover, canopy openness, and humidity. Species with similar wing morphology have responded in a similar way to environmental variables in the studied areas. Functional dispersion was high in the native forest. The monoculture of exotic species may increase the functional attributes related with vulnerability as described by bat wing morphology. Therefore, the native forest conversion to pine forest monoculture may increase the loss of functional attributes in the bat community.

Micronycteris sanborni is an insectivorous bat known from dry phytogeographic domains in South America, although its distribution range is not yet well known. Here, we modelled the distribution of this species based on seven bioclimatic and vegetation predictors associated with its occurrence, using 26 sites where the species was recorded in the Caatinga (16), Cerrado (7), Chiquitano Dry Forest (2) and Pantanal (1). We used four different algorithms to build an ensemble distribution model, to estimate habitat suitability throughout its geographic occurrence and the area of habitat available inside protected areas. Our models showed excellent performance and highlighted the main importance of four environmental variables (other mixed trees, deciduous broadleaf trees, evergreen broadleaf trees, and precipitation of driest quarter), which accounted for more than 80% of the species presence probability. The distribution model indicated the potential occurrence of M. sanborni consistently across the dry diagonal of South America, but adequate habitat areas covered mainly the Caatinga and the northeast of Cerrado rather than the southwest, where suitable habitats were scattered and discontinuous. Less than 10% of the total habitat predicted for M. sanborni corresponded to protected areas. Our results support that M. sanborni mostly depends on woody and less dry environments across the South America dry diagonal, which raises concerns about its vulnerability due to high deforestation in the southwest and because severe dryness is forecast for the coming decades in the Brazilian northeast.

Hispaniola shows the highest environmental heterogeneity among the Greater Antilles mainly due to its complex land relief, encompassing a high ecosystemic heterogeineity, and bats as one o the most representative group of vertebrates. However, the island remains the least studied in the greater Antilles. In this work, we present a first comprehensive approach to the distribution of chiropterans of Hispaniola, product of the synthesis of 5,212 unpublished locality records, and bioclimatic and topographic variables, we fitted Habitat Suitability Models (HSM) and projected bat potential distribution maps, using Maxent. Individual distribution maps were overlapped to obtain a chiropteran richness map, which showed an inverse relationship between species and the elevation. Only three out of the 20 species present on the island were found above 1,500 m a.s.l. As a trend, species richness concentrated in humid forests and dry subtropical forests, typical of the low and medium elevation zones.

Bats play key ecological roles on the islands of Aruba, Bonaire and Curaçao (ABC islands), Caribbean Netherlands; however, most bat species on these islands are either threatened or their conservation status is unknown. We investigated the use of roosts by cave-dwelling bats in this insular system to propose conservation measures aimed at their protection. We conducted bi-monthly species inventories of cave-dwelling bats in 13 of the best-known caves and mines used as day and maternity roosts on the ABC islands. Bats were captured with mist nets and a harp trap (only one cave) placed either inside or at the entrance of the roosts during the first hours (3 to 5 hrs) after sunset. For Aruba and Curaçao, bat monitoring comprised two years of sampling. In the case of Bonaire, depending on the cave, bat monitoring involved one, two or four years of sampling. We identified six species of cave-dwelling bats associated with these roosts, Mormoops megalophylla, Pteronotus davyi, Natalus tumidirostris, Myotis nesopolus, Glossophaga longirostris and Leptonycteris curasoae. All the examined caves and mines were occupied year-round. The two abandoned mines were inhabited exclusively by the nectar-feeding G. longirostris and L. curasoae, whereas caves containing hot chambers were occupied by up to five species of bats, including insect-feeding M. megalophylla, P. davyi, M. nesopolus and N. tumidirostris, and migratory L. curasoae. Nursery roosts occupied by insect-feeding bats were Quadirikiri on Aruba; Orizjan, Pos di watapana and Pos di Antoin on Bonaire; and Raton and Noordkant on Curaçao. Nectar-feeding bats used all the caves and mines examined as day roosts, nursery roosts or both. All the cave-dwelling bats studied had a single annual reproductive period. In the case of insectivorous bats, pregnancy and lactation occurred mainly between July and December, overlapping with the rainy season. For nectar-feeding bats, pregnancy and lactation took place between March and September, overlapping with the flowering and fruiting seasons of chiropterophilous cacti. Most of the examined bat roosts require protection due to one or more of the following conditions: (1) the presence of multiple species dependent on hot chambers, (2) their use as nursery roosts, and (3) the presence of large colonies of L. curasoae.

Xeronycteris Gregorin and Ditchfield, 2005 is a rare monotypic genus of Lonchophyllinae bats endemic to Brazil, with Xeronycteris vieirai Gregorin and Ditchfield, 2005 as the type and sole species. We updated the geographical distribution of the species, including new records from the Cerrado and the Caatinga. Using traditional and geometric morphometric data obtained from 49 museum specimens, including the type series and those representing new records, we describe and discuss the morphological variation of skull shape found in the most comprehensive sample of X. vieirai to date. We also compare similar species and the geographic distribution of X. vieirai and highlight diagnostic traits useful for field identification. Xeronycteris vieirai is now known to occur in 14 localities confirmed by 54 museum specimens housed in Brazilian scientific collections. Records of this species are sparse, as even 15 years after its discovery the knowledge on this species is based on specimens from only a few localities. Specimens of this species show considerable morphological variation in different regions of the skull, especially for a highly specialized nectar-feeding bat, demonstrating variations in the snout and temporomandibular articulation. We discuss endemism issues related to the different biomes where it occurs (in the South American dry diagonal). We also compare these aspects to other bat species with similar geographic distributions, identifying important elements for future research on this species.

Mist nets set at ground level is the traditional method of surveying bats and in the Amazon, almost half of the bat surveys used this methodology. The sole use of ground-level mist nets biases surveys because of the lack of records of aerial insectivorous bats, which forage above the canopy or in other open areas. Canopy mist nets, roost searches and acoustic surveys are methods to survey bat assemblages, but their efficiency compared to ground-level mist nets has not been fully evaluated in the Amazon, the world's largest tropical rainforest. Here, we test how the complementarity of sampling methods contributes to the number of species recorded in bat surveys in the Amazonian rainforest. We simultaneously sampled bats using ground mist nets and ultrasonic recorders at the Ducke Reserve (Central Amazon) in Brazil and did a literature review of bat surveys conducted in the Amazon to assess how these methods have been used in field research during the recent decades. Forty-three bat species were identified using ground mist nets, and seventeen species and five acoustic sonotypes were identified using ultrasonic recorders in Ducke Reserve. The combination of ground mist nets and acoustic recorders registered the largest number of bat species. However, for phyllostomid species the sole use of mist nets was efficient in recording the highest number of species, whereas for aerial insectivores acoustic surveys was the most effective. Of the 54 bat surveys made in the Amazon, 27 localities used complementary methods: roost search, canopy mist nets, harp traps and acoustic surveys. The combination of ground and canopy nets, and ground nets with roost search did not record more phyllostomid bat species than the use of ground nets alone. However, the sole use of acoustic surveys recorded more aerial insectivorous species than any other combination of sampling methods. Using mist nets and acoustic surveys simultaneously, as in our study, results in a dramatic increase in species diversity and different guilds than using only mist nets in the Amazon. Canopy nets and roost search did not increase the total number of species or the number of phyllostomid species in bat surveys. By combining different survey methodologies, we can optimize the recorded diversity of bats, especially using both mist nets and acoustic monitoring.

Telemetry is a widely used method for radio-tracking bats. To minimize negative effects of attaching a tag, like bald spots during hibernation and nursery period, narrowing down the timing of the moult of bats is important. In this study, we investigated the moulting of 11 European bat species with a focus on Myotis daubentonii, Myotis myotis and Pipistrellus pipistrellus. Telemetry data were taken from a 20 years data base. For moulting activity bats were caught with mist nests during their activity period in 2019 and 2020. During data acquisition the condition of the hair was categorized using two different methods: visual hair growth and shed hair pulled off the bats' pelage. Both methods revealed the same results. In general, bats moulted once a year in mid-June (first moult: 17.06) until mid-August (last moult: 13.08), with a significant difference between adult males, reproductive females and non-reproductive females. Adult males (n = 197) and non-reproductive females (n = 60) moulted from mid-June (first moult: 17.06) to end of July (last moult: 27.07), while reproductive females (n = 216) moulted from beginning of July (first moult: 02.07) to mid-August (last moult: 17.08). This variance is probably caused by sex-specific energetic processes like pregnancy, lactation and spermatogenesis. When tagged before moulting season bats could regrow fur in the same year. As seen in recaptured bats (n = 31), tagged in or after this period bats stayed bald during hibernation and reproduction period until the following moulting season. Further studies are needed to specifically assess the impact of bald spots on hibernation and reproductive success. A preceding cost-benefit analysis of the expected knowledge gain versus the potential negative impact on individual and colony scale is recommended.

External ears in mammals direct and enhance perception of sound. In bats, where navigation and foraging are strongly contingent on reception of sound, we would expect correlations between bat external ear morphology and echolocation signal structure, acoustic and aerodynamic properties, and foraging strategies. Using Web search engines, we collected peer-reviewed literature on these relationships, with the aim of summarising the knowledge on these correlations and establishing general form-function patterns. The literature on the relationship echolocation-ear, and foraging strategy was scant (six and ten publications, respectively). Fifteen more examined the aerodynamic properties and 46 the acoustic properties. Because of the complexity of the subject, few attempts exist that examine ear properties (acoustic, aerodynamic, shape) at the same time for more than a few species. The number of species so far examined represents less than 15% of the total number of species of bats. Although the available information did not allow to propose general patterns of morphological response of external ears to the factors examined, our findings suggested that further analyses of the relationship form-function in bat ears should consider the study of ears as integrated, multivariate morphological entities in which shape, aerodynamic characteristics, and acoustic properties, are an integrated, multivariate whole that ultimately contributes to the bat foraging behaviour.