Increasing urban development is moving into natural spaces leading to habitat loss and fragmentation. Understanding and mitigating these anthropogenic pressures is a critical conservation priority. Road networks cause large scale disturbance by fragmenting habitats to connect urban areas. Previous research has indicated that bat activity along forest roads differs depending on road surface type, reporting higher bat activity over paved roads compared to unpaved ones. This suggests an increased collision risk for bats, as paved roads likely experience higher traffic volumes. Our study explores the effect of forest road surface type (paved vs. unpaved) on bats in the Białowieża Forest, Poland. We acoustically sampled bat activity using static detectors at 16 sites, between June and July 2024. We found no significant differences between paved and unpaved forest roads in total bat activity (based on combined call sequences), species richness or at any foraging guild level. We conclude that road surface type is not a determining factor influencing bat activity in ecologically high-value forest habitats. Although the influence of surrounding habitat characteristics was not significant, their effects were variable; therefore, we recommend that future research incorporate a broader range of habitat variables at different spatial scales.

Populations of wide-ranging species on the edge of their geographic range may experience environmental conditions unlike those of conspecifics from the core of the range. We conducted a study on the diet of little brown bats (Myotis lucifugus) near the northern edge of their range in Alaska, USA, using molecular fecal dietary techniques and compared these results to a previous diet study using microscopic analysis of the same samples. Molecular dietary analysis suggested that M. lucifugus in this population rely heavily on flies (Diptera), moths (Lepidoptera), and caddisflies (Trichoptera). Our results are consistent with other studies in the insect orders eaten but differ in the relative importance of those orders compared with molecular analyses of diet from M. lucifugus populations nearer the core species range. Our results also contrast with microscopic assessments of diet from these Alaskan samples, which identified spiders (Araneae) as the primary prey item for this population. Importantly, our study demonstrates how different types of analyses can yield different characterizations of diet, even from the same samples.

Short-tailed fruit bats are widely distributed throughout the Neotropical region, comprising eight species, three of which are found in Brazil: Carollia benkeithi, C. brevicaudum, and C. perspicillata, with C. perspicillata being the most abundant. Studies have raised concerns regarding C. perspicillata and C. brevicaudum due to morphological variability, conflicting diagnostic characteristics, and significant overlap, as well as low interspecific genetic divergence, especially considering their sympatric distribution across various habitats. To address these challenges in taxonomy, a multidisciplinary approach was used to assess the taxonomy of C. perspicillata across different Brazilian phytogeography domains. This approach integrated molecular and morphological data (including linear and geometric morphometrics of the skull). Our findings revealed an overlap in diagnostic characters, although slight morphological differentiation was observed in two specific traits among some specimens: the absence of maxilla curvature at the level of the 2nd premolar in lateral view and variations in coat bandage patterns. The cranial shape and size did not show difference between C. perspicillata and C. brevicaudum with a very low rate of correct classification based on canonical variate analysis (17.9% to 19.2%). Molecular analysis revealed a low genetic divergence of only 2.1%. The Maximum Likelihood (ML) tree displayed two well-supported clades. The ABGD, ASAP, mPTP and GMYC species delimitation models converged in the identification of a single Molecular Operational Taxonomy Unit (MOTU) with specimens that share genetic similarities formed by specimens of Carollia from Brazil (present study), with C. perspicillata from Panama, Ecuador, and French Guiana (GenBank). Across all models, there was no clustering of Carollia species from Brazil (current study) with C. brevicaudum (GenBank). Therefore, the congruence between morphological and molecular findings provides strong evidence for considering a single taxonomy entity in diverse Brazilian phytogeography domains: C. perspicillata.

Understanding the daily activity patterns of species is essential for unravelling the complex strategies animals use for survival and reproduction. These patterns dictate when and how animals interact with their environment, but some species exhibit surprising deviations from their usual activity patterns. In the Gorgona National Natural Park, the lesser sac-winged bat Saccopteryx leptura displays extended diurnal activity that varies spatially depending on the island's vegetation cover. To understand this behaviour, we evaluated whether the extent of diurnal activity is a strategy to avoid nocturnal competition with other insectivorous bats. To this end, we used ultrasonic recorders to capture echolocation pulses at sites with different vegetation covers. We aimed to analyse how the activity patterns of S. leptura and other common insectivorous bats on the island vary spatially. Overall, we found that S. leptura exhibits a diurnal activity peak that extends after sunrise and two nocturnal peaks, contrasting with its insular populations and other species that peak at dawn and night. Furthermore, the diurnal activity pattern varies spatially with vegetation cover, and they are more active at sites with a high night-time activity of other common insectivorous bats on the island, with which they overlap in foraging sites and echolocation frequencies such as Eptesicus chiriquinus and Myotis nigricans. The results suggest that S. leptura adjusts its behaviour to reduce resource competition or acoustic interference, offering a novel perspective on animals' adaptability in insular environments.

The family Phyllostomidae is notable for its remarkable species richness and wide array of unique traits and behaviors, which contribute to ongoing uncertainty about the relationships within the group. Moreover, morphological similarities among some species may result in overlooked diversity. DNA barcoding has proven to be useful in the identification and delimitation of these species. Consequently, the diversity of phyllostomid bats in fragments of the Amazon, Cerrado, and Caatinga biomes was investigated using five species delimitation methods: ABGD, ASAP, mPTP, bPTP, and sGMYC. Our dataset included COI gene sequences from specimens collected in Maranhão's Amazon and Cerrado fragments and the Caatinga in Piauí, supplemented with GenBank sequences. Morphological identification revealed 30 nominal Phyllostomidae species across these biomes, whereas molecular data resolved 29 species, with Carollia represented as a single taxonomic unit at the species level. Delimitation tests identified 32–39 Molecular Operational Taxonomic Units (MOTUs), with at least two MOTUs for eight nominal species: Desmodus rotundus, Diphylla ecaudata, Gardnerycteris crenulatum, Phylloderma stenops, Micronycteris minuta, Hsunycteris thomasi, Trachops cirrhosus, and Trinycteris nicefori. Our results further indicate a relationship between the average intraspecific genetic distance and the presence of different lineages, suggesting that observed diversity patterns likely reflect undocumented species diversity. This reveals that phyllostomid bat diversity in Brazilian biomes is underestimated, with evidence of underscribed or not yet fully understood taxa, evolutionary distinct lineages, and cryptic species.

The metabolism of large numbers of bats roosting in confined cave spaces is expected to produce extreme microclimatic conditions (such as extreme heat, CO2 concentrations, ammonia levels). Here, we report a quantitative estimate of 12,661 ± 1,686 Pteronotus (Mormoopidae) individuals in Costa Rica's largest subterranean bat roost. This small cave has a roost area of only ca. 30 m2, equivalent to an average density of 426 bats/m2. Metabolic products of this dense accumulation of bats were expected to produce extreme concentrations of gaseous ammonia. However, atmospheric ammonia concentration in the cave was shown to fall well below modelled expectations, reaching a maximum of 145 ug/m3. We show that most of the ammonia derived from the breakdown of urinary nitrogen must dissolve into guano pore water and wall condensation rather than be released as gaseous ammonia as would occur under drier conditions. Air temperature in the center of the roost rises to ca. 34°C, consistent with our observations in a wide range of bat caves where roost ambient temperature never equals or exceeds bat body temperature. Moreover, the cave microclimate exhibits a circadian rhythm which we attribute to bat movement.

Los animales utilizan varios criterios para optimizar sus decisiones de búsqueda de alimento. Los murciélagos frugívoros satisfacen casi todas sus necesidades nutricionales a partir de las frutas que consumen, y varios estudios indican que las diferentes calidades de las frutas pueden afectar el comportamiento alimentario. Esto podría reflejar la historia evolutiva y la influencia mutua de plantas y frugívoros. Sin embargo, las preferencias por el azúcar entre los mamíferos frugívoros son inconsistentes. Este estudio compara las preferencias de madurez del murciélago frugívoro de importancia ecológica, Carollia perspicillata, en Panamá. Demostramos que el contenido de azúcar predice significativamente tanto la cantidad como la calidad de la fruta consumida. Descubrimos que los murciélagos exhiben fuertes preferencias por las frutas maduras y demasiado maduras, buscándolas más rápidamente que las frutas inmaduras, que eran consistentemente menos favorecidas. También discutimos cómo los factores internos pueden influir en las decisiones de alimentación de estos murciélagos.

In bats of the temperate zone, survival throughout hibernation strongly depends on fine tuning the balance between the amount of fat reserves built in late summer or fall and the energy expenses. The latter are affected to a large extent by occasional arousals and active episodes. Reports of the activity of bats during the hibernation period and of its relationships with environmental conditions are therefore of utmost importance. The winter activity of the threatened western barbastelle (Barbastella barbastellus) is poorly described, but indirect observations (body mass loss, intra-cave displacements in winter) suggest that it might be frequent. We describe the phenology of acoustic activity (number of passes per night) displayed by the western barbastelle during hibernation (October–March) at Grotte aux Fées, a natural limestone cave of the Swiss Jura. Calls were recorded automatically at the cave's entrance and within the cave's main chamber with the aim to test whether the phenology of acoustic activity throughout the hibernation period would be similar at the two sites. We also test for the effect of weather variables (ambient temperature and precipitation) on acoustic activity in mid-hibernation. Acoustic activity followed a bimodal pattern at the entrance porch, with peaks corresponding to arrival at- and departure from the cave. Minimum acoustic activity was observed in January (median 2–3 passes/night), but even then, passes were recorded during most nights. Within the cave's main chamber, the phenology of acoustic activity differed from that at the entrance. Activity remained consistently high throughout the winter (median 27 passes/night in January). In January, acoustic activity was significantly and positively affected by ambient temperature, but not by precipitation. Even intra-cave activity was positively affected by external ambient temperature. At Grotte aux Fées, barbastelles deposited feces in winter and it is known that a rise of ambient temperature stimulates the activity of moths, the principal food resource of the western barbastelle. Our results suggest that B. barbastellus often has high energy expenses during hibernation and the extent to which these expenses are partly balanced by opportunistic feeding in winter awaits further study.

Micronycteris yatesi was described in 2013 and has previously been considered endemic to Bolivia. Through the analysis of morphological data and mitochondrial cytochrome-b sequences (cytb) from two pale-bellied Micronycteris specimens from the Cerrado (Mato Grosso, Brazil), we report the first record of M. yatesi in this country. Our comparative analyses included related species: M. minuta, M. sanborni, M. tresamici, and M. simmonsae. The sequences from the Brazilian specimens form a statistically well-supported clade in our maximum-likelihood phylogenetic analysis, alongside sequences from the holotype and paratypes of M. yatesi from Bolivia. The identification of these specimens as M. yatesi is further supported by morphological characteristics, with the Brazilian specimens clustering closely with Bolivian M. yatesi in multivariate morphometric analysis. Within M. yatesi, the cytb phylogeny suggests a closer relationship between the Brazilian specimens and the easternmost samples from Bolivia, reflecting a pattern of similarity consistent with their geographical proximity. We emphasize the urgent need to enhance our understanding of this species, particularly in the critically endangered Cerrado region of Brazil.

Trophic dimensions of syntopic species provide information by which drivers of resource partitioning and species coexistence can be evaluated. Specialization on unique prey can minimize competition among different bat species of the same community and provide researchers and managers with insights useful for determining how resources are partitioned among species. We used stable isotope analyses of carbon (δ13C) and nitrogen (δ15N), coupled with wing morphology of bat species to estimate species-specific resource overlap and niche metrics. Isotopic ratios of δ13C and δ15N were obtained from fur of all netted bat species, which included, Eptesicus fuscus, Lasiurus borealis, Nycticeius humeralis, Corynorhinus rafinesquii, Lasiurus seminolus, and Myotis austroriparius. Results of the stable isotope analysis revealed that several species (C. rafinesquii, M. austroriparius and N. humeralis) had distinct isotopic niches but considerable overlap among others (E. fuscus, L. borealis and L. seminolus). Where stable isotope niches overlapped, morphological parameters were used to explain isotopic niche partitioning in the same habitat. The smallest isotopic niche of Corynorhinus rafinesquii indicated a small trophic niche, suggesting that this species may be more susceptible to perturbations, such as changes in prey availability and foraging habitat. Determining trophic niches of local bat assemblages will aid in better understanding resource partitioning among bat species and inform habitat managers of foraging ecology of species to guide conservation.