Insectivorous Bats Research Articles

Fruit bats trade in the traditional markets of South Minahasa, North Sulawesi, Indonesia

Abstract. Ransaleleh TA, Kawatu M, Wahyuni I, Onibala J, Nangoy MJ, Umboh S, Rembet UNWJ, Saputro S, Wiantoro S. 2024. Fruit bats trade in the traditional markets of South Minahasa, Sulawesi, Indonesia. Biodiversitas 25: 716-725. The hunting and trading of fruit bats are significant sources of income for several communities in North Sulawesi, Indonesia. Therefore, this research aimed to map the market locations and identify the species of traded bats, along with their conservation status in South Minahasa District. Surveys of markets, hunters, and sellers were conducted for 5 months from May to September 2023. Morphological examinations were carried out on the traded bats, focusing on several parameters such as body weight, morphometric and description of the morphological characters. We identified the traditional markets which sell fruit bats (family Pteropodidae), Acerodon celebensis and Pteropus alecto meat, namely Berdikari Tumpaan, 54 Amurang, 45 Langsot Tareran, Tenga, Pakuure, Ongkaw, Soko Raanan Baru, Motoling, Poigar, Poopo, Pinaesaan Tompaso Baru, and Pinasungkulan Modoinding. Furthermore, two markets, namely Pakuure and Pinaesaan Tompaso Baru, were identified selling the small fruit bats (family Pteropodidae), Cynopterus minutus, Dobsonia exoleta, Nyctimene cephalotes, Rousettus amplexicaudatus, and Thoopterus nigrescens. According to the International Union for Conservation of Nature (IUCN) Red List, A. celebensis and D. exoleta are endemic bat species in Sulawesi with a conservation status of vulnerable and least concern, respectively. Fostering education and advocacy program is crucial to promote awareness and conservation strategy, especially for the 12 traditional markets which trade seven fruit bat species in South Minahasa, Sulawesi.

Comparative light and scanning electron microscopic studies of the lenses in the insectivorous bat (Pipistrellus kuhlii) and Egyptian fruit bat (Rousettus aegyptiacus).

Bats have the ability to fly without eye application in the darkness. In this study, we aimed to characterize the functional and structural acclimations of the lenses of two common bats with a various lifestyle in the Egyptian environment: the insectivorous bat (IB) (Pipistrellus kuhlii) and Egyptian fruit bat (FB) (Rousettus aegyptiacus). From each species, seven lenses were extracted from adult eyes. The scanning electron microscopic (SEM) and light microscopic examination of the lens were carried out. FB lenses were made up primarily of fiber cells and sheets, which were encapsulated by a thin collagenous capsule and covered by single epithelial layer anteriorly. On the other hand, the IB lens had two poles and was visibly oval shaped. Both lenses had epithelial cells of the same cuboidal form that were subjected to continuous division and differentiation into new fiber cells at the center. SEM revealed that the normal FB lens had regularly organized shells of fiber cells of intact lens fibers which were connected by membrane interdigitations with different shapes mainly ball-and-socket junctions through the superficial cortical fiber cells. The IB lens was composedof parallel, evenly spaced fibers with various types of interdigitations between fibers that can be seen and increased close to the middle region revealing tiny bumps along the scrubby portions and sockets and balls in the center of the wide portions. Near the center of both lenses, there were large interlocking paddles with little and lengthy protrusions along their short sides. In conclusion, our study discovered several ultrastructural and structural variations among the investigated species. The detection of specialized membrane interdigitations with different shapes protruding from the lens fiber sheets is considered the most characteristic of the FB lens. RESEARCH HIGHLIGHTS: FB lens has more organized sheets of fibers parallel to each other than IB lens. Different shapes of interdigitations protruded from the FB lens have been detected. Interlocking paddles, balls, and sockets with tongue-like fiber flabs are characteristic to FB lens.

Molecular and morphological data suggest a new species of big-eared bat (Vespertilionidae: Corynorhinus) endemic to northeastern Mexico.

Corynorhinus mexicanus is an insectivorous bat endemic to Mexico that inhabits the high and humid regions of the Sierra Madre Oriental (SMO), the Trans-Mexican Volcanic Belt (TMVB), and the Sierra Madre Occidental (SMOC). A previous study suggested that C. mexicanus could be a cryptic species complex due to the genetic divergence observed between specimens from the TMVB and SMOC. The present study implemented phylogenetic, population genetics, and morphological analyses to evaluate the hypothesis that C. mexicanus is a species complex. The phylogenetic analysis indicated that C. mexicanus is a polyphyletic species composed of three indirectly related lineages. The estimated divergence times for the lineages suggest that they first originated during the Pliocene, while the second and third shared a common ancestor with C. townsendii 1.55 million years ago, and diverged 600,000 years ago during the Middle Pleistocene. The population genetics analysis reveals the SMO lineage of C. mexicanus is an isolated genetic group and highly diverged from the rest of lineages (SMOC and TMVB). The morphological analyses showed variation in the skull and mandible associated with the lineages and sex of the specimens, highlighting a difference in mandible shape between the specimens of the SMO and the rest of C. mexicanus. The results of this study suggest the presence of an undescribed species of the genus Corynorhinus.

New record of Myotis ciliolabrum (Merriam, 1886) (Mammalia, Chiroptera) from the State of Mexico, Mexico

Myotis ciliolabrum (Merriam, 1886) is an insectivorous bat of the family Vespertilionidae and has a wide distribution from British Columbia, Alberta, and Saskatchewan in Canada, most of the western and central United States of America to central Mexico. In this study, we report one of the southernmost records from State of Mexico, based on two females collected in 1980 and stored in the Mammals Collection of the Universidad Autonóma Metropolitana. These records increases the knowledge on the distribution of this rare bat in Mexico.

Species richness in Myotis (Chiroptera: Vespertilionidae): species delimitation and expanded geographic sampling reveal high Neotropical diversity

Abstract With up to 137 species worldwide, Myotis,— a genus of small, insectivorous bats are an example for understanding biogeographic and evolutionary processes such as intercontinental colonization, diversification, speciation, and convergent adaptive evolution. Species limits and associated distributions, however, remain poorly delineated across significant portions of this diverse group and encompassing a vast geographic range. Here, we explore how diversity is partitioned across this radiation with a focus on Neotropical species of Myotis, using a barcoding approach (706 bp of the mitochondrial DNA gene cytochrome-b) that includes 544 individual sequences (116 newly generated sequences and 428 sequences from GenBank, including outgroups). Single-locus molecular barcoding is useful for identifying cryptic diversity and establishing hypotheses that can guide investigations of species boundaries and phylogenetic relationships, an especially important initial step in assessing poorly characterized, diverse clades. The global phylogeny produced from these data is consistent with the hypothesized monophyly of the New World clade and places the evolutionary relationships of Neotropical species of Myotis within the context of the Palearctic and Nearctic clades. We then explore species boundaries for 25 of the 36 nominal species of Neotropical Myotis, using 3 alternative species delimitation approaches (1 distance-based ABGD [Automatic Barcode Gap Discovery]; and 2 coalescent-based mPTP [multi-rate Poisson Tree Processes], GMYC [Generalized Mixed Yule Coalescent] model). The mPTP (n = 29 species) and ABGD (n = 26) approaches inferred different numbers of species than that recognized by current Neotropical Myotis taxonomy, whereas GMYC (n = 25) inferred the same number of species. In addition to the original 36 Neotropical nominal species currently recognized, we suggest that taxonomic revisions are needed to assess whether M. oxyotus gardneri and M. nigricans osculatii should be elevated to the species level and whether M. dinellii is distinct from M. levis. With the 7 potentially cryptic species identified herein that require further study, the number of Neotropical Myotis may approach 45 species. Taken together, our results suggest that rather than a classic example of a temperate radiation, there may be more species of Myotis in the Neotropics than Nearctic, Afrotropic, Indomalayan, and Oceanian Realms, with only the Palearctic region showing higher species richness.

Rates of diagenesis of tropical insectivorous bat guano accumulations: implications for potential paleoenvironmental reconstruction

Cave guano deposits are increasingly being recognized as valuable repositories of paleo-climatic and paleo-environmental information. However, that value is constrained by rates of guano decomposition, and these rates have not been previously well-studied. Here we show that field and laboratory studies of deep insectivorous bat guano sequences in the caves of Borneo demonstrate the extreme dependence of decomposition rate on guano water content. Under tropical conditions, moist guanos exhibit decomposition coefficients (k) values of ~ 0.01, implying the loss of most of the organic content on decadal timescales. Under similar temperatures but drier conditions, k values drop to ~3 x 10-6, permitting significant organic (chitin) content to persist for tens of thousands of years. One of the implications of these findings for paleo-environmental records older than the limit of carbon dating is that a value for k can be calculated based on a single carbon date, which then allows an estimate of likely age at base of deposit.

Absence of lunar phobia in European swarming vespertilionid bats

“Lunar phobia” in bats has been widely discussed since its description in tropical bats in 1978. The phenomenon has been frequently contested and supported and was first reported in European bats in 2020. Our study seeks to clarify the debate by describing the relationship between the activity of selected swarming vespertilionid bats (Family: Vespertilionidae) and moonlight levels. To verify a potential connection to the latter, a swarming dataset was analysed in respect of estimated moonlight illumination. Moonlight estimates were based on geographical location and several lunar parameters, to accurately characterise the non-linear relationship between moon phase and illumination (lux). The swarming data consisted of 32 netting and 14 echolocation recording sessions collected between August and October 2014 and 2015. Our data included 3,265 netted bats from 13 species and 15,919 bat calls from 10 confirmed species. Data was collected at the large Central European hibernation/swarming site – Natura 2000 PLH080003 “Nietoperek” in western Poland (N 52.394400, E 15.480600). Generalised linear mixed models (GLMMs) determined insignificant relationships between bats and moonlight illumination. Our analysis confirms an absence of impact of moonlight intensity on swarming bats and thereby rejects the lunar phobia phenomena in at least six insectivorous bat species (Myotis myotis, M. daubentonii, M. nattereri, M. bechsteinii, Barbastella barbastellus, Plecotus auritus) swarming in the autumn.

Musculoskeletal morphogenesis supports the convergent evolution of bat laryngeal echolocation.

The order Chiroptera (bats) is the second largest group of mammals. One of the essential adaptations that have allowed bats to dominate the night skies is laryngeal echolocation, where bats emit ultrasonic pulses and listen to the returned echo to produce high-resolution 'images' of their surroundings. There are two possible scenarios for the evolutionary origin of laryngeal echolocation in bats: (1) a single origin in a common ancestor followed by the secondary loss in Pteropodidae, or (2) two convergent origins in Rhinolophoidea and Yangochiroptera. Although data from palaeontological, anatomical, developmental and genomic studies of auditory apparatuses exist, they remain inconclusive concerning the evolutionary origin of bat laryngeal echolocation. Here we compared musculoskeletal morphogenesis of the larynx in several chiropteran lineages and found distinct laryngeal modifications in two echolocating lineages, rhinolophoids and yangochiropterans. Our findings support the second scenario that rhinolophoids and yangochiropterans convergently evolved advanced laryngeal echolocation through anatomical modifications of the larynx for ultrasonic sound generation and refinement of the auditory apparatuses for more detailed sound perception.

Comparative anatomy of the vocal apparatus in bats and implications for the diversity of laryngeal echolocation

Abstract Most of over 1400 extant bat species produce high-frequency pulses with their larynx for echolocation. However, the debate about the evolutionary origin of laryngeal echolocation in bats remains unresolved. The morphology of the larynx is known to reflect vocal adaptation and thus can potentially help in resolving this controversy. However, the morphological variations of the larynx are poorly known in bats, and a complete anatomical study remains to be conducted. Here, we compare the 3D laryngeal morphology of 23 extant bat species of 11 different families reconstructed by using iodine contrast-enhanced X-ray microtomography techniques. We find that, contrary to previously thought, laryngeal muscle hypertrophy is not a characteristic of all bats and presents differential development. The larynges of Pteropodidae are morphologically similar to those of non-bat mammals. Two morphotypes are described among laryngeal echolocating bats, illustrating morphological differences between Rhinolophoidea and Yangochiroptera, with the main variations being the cricothyroid muscle volume and the shape of the cricoid and thyroid cartilages. For the first time we detail functional specialization for constant frequency echolocation among Rhinolophoidea. Lastly, the nasal-emitting taxa representing a polyphyletic group do not share the same laryngeal form, which raises questions about the potential modular nature of the bat larynx.

Metagenomic of Liver Tissue Identified at Least Two Genera of Totivirus-like Viruses in Molossus molossus Bats.

The Totiviridae family of viruses has a unique genome consisting of double-stranded RNA with two open reading frames that encode the capsid protein (Cap) and the RNA-dependent RNA polymerase (RdRpol). Most virions in this family are isometric in shape, approximately 40 nm in diameter, and lack an envelope. There are five genera within this family, including Totivirus, Victorivirus, Giardiavirus, Leishmaniavirus, and Trichomonasvirus. While Totivirus and Victorivirus primarily infect fungi, Giardiavirus, Leishmaniavirus, and Trichomonasvirus infect diverse hosts, including protists, insects, and vertebrates. Recently, new totivirus-like species have been discovered in fish and plant hosts, and through metagenomic analysis, a novel totivirus-like virus (named Tianjin totivirus) has been isolated from bat guano. Interestingly, Tianjin totivirus causes cytopathic effects in insect cells but cannot grow in mammalian cells, suggesting that it infects insects consumed by insectivorous bats. In this study, we used next-generation sequencing and identified totivirus-like viruses in liver tissue from Molossus molossus bats in the Amazon region of Brazil. Comparative phylogenetic analysis based on the RNA-dependent RNA polymerase region revealed that the viruses identified in Molossus bats belong to two distinct phylogenetic clades, possibly comprising different genera within the Totiviridae family. Notably, the mean similarity between the Tianjin totivirus and the totiviruses identified in Molossus bats is less than 18%. These findings suggest that the diversity of totiviruses in bats is more extensive than previously recognized and highlight the potential for bats to serve as reservoirs for novel toti-like viruses.

Temporal mismatches in flight activity patterns between Pipistrellus kuhlii and Prays oleae in olive farms: Implications for biocontrol services potential

Abstract Biocontrol services are widely recognized to provide key incentives for bat conservation. However, we have virtually no information on whether and how disruptions in bat‐mediated biocontrol services are driven by mismatches between the temporal activity patterns of insectivorous bats and insect pests. We investigated the temporal relationship between the nightly activity patterns of the common pipistrelle bat (Pipistrellus kuhlii) and the olive fruit moth (Prays oleae). Temporal mismatches between species pairs were estimated as the time difference (expressed as a percentage of the night) at which P. kuhlii and P. oleae reached 50% of their abundance. The study was carried out during spring, summer, and fall between 2017 and 2019 in 60 olive farms representing increasing levels of structural simplification (as a surrogate of agricultural intensification). Olive farms were classified as exhibiting high (i.e. HIGH olive farms; n = 27), intermediate (MID; n = 18), and low (LOW; n = 15) structural complexity. Temporal mismatches between the activity levels of P. kuhlii and P. oleae varied between seasons and types of olive farms, being comparatively lower in summer than in spring and fall. Furthermore, summer was the only season in which temporal mismatches between species pairs differed between types of olive farms, with higher temporal mismatches found in LOW than in HIGH and MID olive farms. Overall, our work demonstrates the existence of temporal mismatches between the nightly activity patterns of P. kuhlii and P. oleae. Furthermore, it demonstrates that the structural simplification of olive farms increases temporal mismatches between species pairs, particularly in summer when bat‐mediated biocontrol services are most needed. Synthesis and applications. Future research should consider mismatches between the temporal activity patterns of insectivorous bats and insect pests. Otherwise, the actual impact of agricultural intensification on bat‐mediated biocontrol services as well as the economic impact of their loss on the agriculture industry might be underestimated. To enhance biocontrol services, we propose increasing the availability of suitable roosting and foraging sites as well as conserving areas of remnant native woodland and scattered hollow‐bearing trees.

Restoration of boreal wetlands increases bat activity

Wetlands are important habitats for insectivorous bats, as the presence of water promotes insect abundance and provides drinking water for wildlife, and therefore could promote bat conservation. Research on bats and wetlands has mainly focused on constructed wetlands, and with a geographical emphasis on eastern United States and central Europe, whereas relatively little is known about the effects of wetland restoration on bats, especially in the boreal zone. We conducted a Before‐After‐Control‐Impact (BACI) study in 21 wetlands. Using acoustic survey techniques, we collected information on bats both before and after restoration, with 7 of the 21 wetlands acting as control sites and 14 as impact (i.e., restored) sites. Acoustic surveys were conducted in May–September in the years 2018, 2019 (before restoration) and in 2021 and 2022 (after restoration). Species detection for each night was assessed by automated analysis of audio recordings. We assessed the presence and number of active minutes of the Northern bat (Eptesicus nilssonii) and the Myotis species group, using a generalized linear mixed model. Wetland restoration increased the acoustic activity of both taxa, but not their presence. Thus, restoration increased the usage of wetlands as a feeding site for bats. Our BACI study provides strong evidence that wetland restoration caused an increase in bat activity, and can be used as an effective tool for bat conservation.

Integrative single-cell characterization of a frugivorous and an insectivorous bat kidney and pancreas

Frugivory evolved multiple times in mammals, including bats. However, the cellular and molecular components driving it remain largely unknown. Here, we use integrative single-cell sequencing (scRNA-seq and scATAC-seq) on insectivorous (Eptesicus fuscus; big brown bat) and frugivorous (Artibeus jamaicensis; Jamaican fruit bat) bat kidneys and pancreases and identify key cell population, gene expression and regulatory differences associated with the Jamaican fruit bat that also relate to human disease, particularly diabetes. We find a decrease in loop of Henle and an increase in collecting duct cells, and differentially active genes and regulatory elements involved in fluid and electrolyte balance in the Jamaican fruit bat kidney. The Jamaican fruit bat pancreas shows an increase in endocrine and a decrease in exocrine cells, and differences in genes and regulatory elements involved in insulin regulation. We also find that these frugivorous bats share several molecular characteristics with human diabetes. Combined, our work provides insights from a frugivorous mammal that could be leveraged for therapeutic purposes.

Description of the echolocation pulses of insectivorous bats with new records for Southwest Colombia

Despite the high diversity of bats in neotropics, traditional methods such as mist nets, harp traps and roost detection have limitations in capturing that diversity in a landscape, with most detected species restricted to those that forage in the undergrowth or enclosed spaces. Therefore, acoustic records become a tool that complements and enhances the efforts to get more complete bat inventories while avoiding alterations in usual foraging activities and disruption in their life cycles. This study describes the acoustic parameters (spectral and temporal variables) of the echolocation pulses of insectivorous bats to characterise different species of bats in Southwest Colombia acoustically. We recorded echolocation calls between December 2017 and May 2020 in the Andean and Pacific regions of the Department of Nariño. We analysed 81 sequences of echolocation calls from eight bat species belonging to three families: Vespertilionidae, Molossidae and Emballonuridae. We perform recordings on free-flying bats with identity corroboration by capture for recording in flight rooms and examination in the hand. Myotis riparius and Lasiurus blossevillii were recorded for the first time in the Nariño Department. M. albescens, M. keaysi, M. riparius and L. blossevillii (Vespertilionidae) had pulses of frequency modulated (FM) with a quasi-constant frequency (QCF) ending; Molossus molossus, Tadarida brasiliensis and Promops centralis (Molossidae) had pulses with constant frequency (CF) and QCF; and Saccopteryx bilineata (Emballonuridae) had pulses with QCF. This study contributes to the efforts to facilitate the identification of insectivorous bats of the Neotropics using the acoustic monitoring approaches, represents a reference to compare the acoustic studies in Southwestern Colombia and contributes to increasing our knowledge of the bat diversity in the region.

A bat a day keeps the pest away: Bats provide valuable protection from pests in organic apple orchards

Organic farming is an essential component of sustainable agriculture that can help maintain biodiversity in agricultural landscapes, providing benefits for both human well-being and environmental conservation. Recent studies have highlighted the vital role of insectivorous bats in farmland ecosystems in controlling pest insect populations. Our research focuses on the direct economic value of bat insectivory in woody crops, specifically in apple orchards affected by the codling moth Cydia pomonella. We conducted an exclusion experiment followed by an economic evaluation to estimate the impact of bat insectivory on crop damage and economic savings. Our results demonstrate that the presence of bats in apple orchards can significantly reduce the damage caused by C. pomonella, resulting in a 32.1% reduction in affected apple trees and a 50% reduction in the total weight of damaged apples per tree. This translates to estimated economic savings of 551 €/ha/y by reducing the need for insecticide applications and, consequently, minimizing the negative impacts of such chemicals on the environment and human health. Moreover, the presence of bats can lead to higher crop yields and protect the quality of the product, resulting in higher profits for farmers. Our findings highlight the critical role of bats in maintaining ecosystem services and provide valuable information for the sustainable management of farmland ecosystems.

Insectivorous bat activity dataset across different land-use types in the Islands of São Tomé and Príncipe, Central West Africa.

São Tomé and Príncipe oceanic islands, in Central West Africa, are characterised by exceptional levels of endemism. Since human colonisation in the mid-15th century, São Tomé and Príncipe have lost 74% and 67% of their native habitat, respectively. Today, these islands are mainly covered by remaining old-growth forests, secondary regrowth forests, shaded plantations (mostly of cocoa), oil palm plantations (in the case of São Tomé), small-scale agricultural areas and urban areas. Yet, little is known about how species on these islands are coping with land-use changes. Island ecosystems are particularly important for bats, with about 25% of the world's bat species being entirely restricted to island systems. São Tomé and Príncipe Islands comprise six and four native insectivorous bats, respectively. Two species, Chaerephontomensis and Macronycteristhomensis, are island-endemics in São Tomé; Pseudoromiciaprincipis is an island-endemic in Príncipe; and Miniopterusnewtoni is endemic from both São Tomé and Príncipe. Here, we present a dataset comprising a comprehensive compilation of occurrence records derived from acoustic sampling of insectivorous bats across the predominant land-use types of both the São Tomé and Príncipe Islands. In each sampling site, standardised surveys consisted of deploying one Audio Moth device that recorded for 1 minute every 5 minutes over a 48-hour period. We identified a total of 19,437 bat-passes across the 115 sites surveyed in São Tomé Island and 17,837 bat-passes across the 50 sites surveyed in Príncipe Island. Based on a sampling effort of 1,584 hours of recordings manually processed to identify all the contained bat passes, this dataset, publicly available on GBIF, provides comprehensive information on the activity of insectivorous bats across two endemic-rich oceanic islands in the Gulf of Guinea. For each bat pass identified, we report the identified species, geographic coordinates, land-use type, altitude, date and time. This is the first public dataset providing detailed information on species-level habitat use for insectivorous bats on oceanic islands in Africa.

Expanding the knowledge of the bat fauna of the Brazilian Caatinga: new geographical records of molossid bats (Chiroptera, Molossidae) for the Chapada Diamantina region, with taxonomic notes.

The Caatinga, an exclusive biome in Brazil, is the largest tropical dry forest area in the Americas. It is characterized by a semi-arid climate and various soils that harbor a great diversity of flora and fauna. Novel records of aerial insectivorous bat species in the family Molossidae in the Chapada Diamantina, northeastern Brazil are presented. The study is based on field sampling of 115 molossid bat specimens from six genera and 12 taxonomically confirmed species, along with four taxa requiring further evaluation for definitive species identification. All specimens were obtained using mist nets around a small freshwater lagoon surrounded by semideciduous dry forest. The verified genera were Cynomops, Eumops, Molossops, Molossus, Neoplatymops, and Nyctinomops. Our findings enhance the understanding of bat diversity in the Brazilian Caatinga, with the first records of Eumopsdelticus, E.bonariensis, and Molossuscurrentium. The most abundant species were Molossusrufus, Eumopsglaucinus, Cynomopsplanirostris, Nyctinomopslaticaudatus, and Molossusmolossus. Previously unreported morphological and morphometric variations for these Caatinga taxa were examined. Additionally, information on sexual dimorphism in craniodental characteristics of Molossopstemminckii and variations in the presence of the sagittal crest in Neoplatymopsmattogrossensis are provided. Based on the voucher specimens from this study, the recognized number of species of Molossidae known from the Caatinga has increased to 21. Our results offer new insights into the taxonomy and biogeography of Neotropical molossids, highlighting their importance as members of bat communities in dry forest ecosystems from northeastern South America.

Raiva felina por variante viral de morcegos insetívoros

ABSTRACT: Rabies is an invariably fatal infectious-contagious viral disease caused by viruses in the genus Lyssavirus, which affects the central nervous system of domestic and wild mammals. This study draws attention to the importance of insectivorous bats and domestic cats in the epidemiology of rabies. For this, two cases of rabies registered in domestic cats in the southeast region of Rio Grande do Sul were analyzed. Diagnoses were based on histological alterations and positive staining for the virus in direct immunofluorescence with confirmation by biological test, immunohistochemical evaluation and identification of the rabies virus variant by polymerase chain reaction. In Brazil, a change in the epidemiological profile of rabies has been observed, in which bats play a major role in the current chain of transmission of the disease. It is noteworthy, that the antigenic viral variant AgV-4, typical of the insectivorous bat Tadarida brasiliensis, was identified in the domestic cats affected in this study.

Discrimination of object information by bat echolocation deciphered from acoustic simulations.

High-precision visual sensing has been achieved by combining cameras with deep learning. However, an unresolved challenge involves identifying information that remains elusive for optical sensors, such as occlusion spots hidden behind objects. Compared to light, sound waves have longer wavelengths and can, therefore, collect information on occlusion spots. In this study, we investigated whether bats could perform advanced sound sensing using echolocation to acquire a target's occlusion information. We conducted a two-alternative forced choice test on Pipistrellus abramus with five different targets, including targets with high visual similarity from the front, but different backend geometries, i.e. occlusion spots or textures. Subsequently, the echo impulse responses produced by these targets, which were difficult to obtain with real measurements, were computed using three-dimensional acoustic simulations to provide a detailed analysis consisting of the acoustic cues that the bats obtained through echolocation. Our findings demonstrated that bats could effectively discern differences in target occlusion spot structure and texture through echolocation. Furthermore, the discrimination performance was related to the differences in the logarithmic spectral distortion of the occlusion-related components in the simulated echo impulse responses. This suggested that the bats obtained occlusion information through echolocation, highlighting the advantages of utilizing broadband ultrasound for sensing.

Bat coronavirus was detected positive from insectivorous bats in Krau Wildlife Reserve Forest.

Bats are flying mammals with unique immune systems that allow them to hold many pathogens. Hence, they are recognised as the reservoir of many zoonotic pathogens. In this study, we performed molecular detection to detect coronaviruses, paramyxoviruses, pteropine orthoreoviruses and dengue viruses from samples collected from insectivorous bats in Krau Reserve Forest. One faecal sample from Rhinolophus spp. was detected positive for coronavirus. Based on BLASTN, phylogenetic analysis and pairwise alignment-based sequence identity calculation, the detected bat coronavirus is most likely to be a bat betacoronavirus lineage slightly different from coronavirus from China, Philippines, Thailand and Luxembourg. In summary, continuous surveillance of bat virome should be encouraged, as Krau Reserve Forest reported a wide spectrum of biodiversity of insectivorous and fruit bats. Moreover, the usage of primers for the broad detection of viruses should be reconsidered because geographical variations might possibly affect the sensitivity of primers in a molecular approach.