Hipposideros Research Articles

Prevalent harmonic interaction in the bat inferior colliculus.

Animal vocalizations and human speech are typically characterized by a complex spectrotemporal structure, composed of multiple harmonics, and patterned as temporally organized sequences. However, auditory research often employed simple artificial acoustic stimuli or their combinations. Here we addressed the question of whether the neuronal responses to natural echolocation call sequences can be predicted by manipulated sequences of incomplete constituents at the midbrain inferior colliculus (IC). We characterized the extracellular single-unit activity of IC neurons in the great roundleaf bat, Hipposideros armiger (both sexes), using natural call sequences, various manipulated sequences of incomplete vocalizations, and pure tones. We report that approximately two-thirds of IC neurons exhibited a harmonic interaction. Neurons with high harmonic interactions exhibited greater selectivity to natural call sequences, and the degree of harmonic interaction was robust to the natural amplitude variations between call harmonics. For 81% of the IC neurons, the responses to the natural echolocation call sequence could not be predicted by altered sequences of missing call components. Surprisingly, nearly 70% of the neurons that showed a harmonic interaction were characterized by a single excitatory response peak as revealed by pure tones. Our results suggest that prevalent harmonic processing has already emerged in the auditory midbrain inferior colliculus in the echolocating bat.Significance Statement Auditory cortex has long been suggested to be the main region for processing complex sound such as natural vocalizations. However, this cortex-centered view of complex stimuli processing was largely based on simple stimuli or their combinations, ignoring many crucial aspects of natural communication behaviors. Here, we took a neuroethological perspective to study the harmonic processing in the inferior colliculus, in the great roundleaf bat. We show that prevalent harmonic processing has already emerged in the auditory midbrain in the echolocating bat. Critically, harmonic interactions revealed by natural call sequences cannot be predicted by responses to either pure tones or altered sequences of missing call components. Our data suggest that auditory midbrain is involved in harmonic processing in the echolocating bat.

Design of hepadnavirus core protein-based chimeric virus-like particles carrying epitopes from respiratory syncytial virus

Respiratory syncytial virus (RSV) is one of the most important pathogens causing respiratory tract infection in humans, especially in infants and the elderly. The identification and structural resolution of the potent neutralizing epitopes on RSV fusion (F) protein enable an “epitope-focused” vaccine design. However, the display of RSV F epitope II on the surface of the widely-used human hepatitis B virus core antigen (HBcAg) has failed to induce neutralizing antibody response in mice. Here, we used the hepadnavirus core protein (HcAg) from different mammalian hosts as scaffolds to construct chimeric virus-like particles (VLPs) presenting the RSV F epitope II. Mouse immunization showed that different HcAg-based chimeric VLPs elicited significantly different neutralizing antibody responses, among which the HcAg derived from roundleaf bat (RBHcAg) is the most immunogenic. Furthermore, RBHcAg was used as the scaffold platform to present multiple RSV F epitopes, and the immunogenicity was further improved in comparison to that displaying a single epitope II. The designed RBHcAg-based multiple-epitope-presenting VLP formulated with MF59-like adjuvant elicited a potent and balanced Th1/Th2 immune response, and offered substantial protection in mice against the challenge of live RSV A2 virus. The designed chimeric VLPs may serve as the potential starting point for developing epitope-focused vaccines against RSV. Our study also demonstrated that RBHcAg is an effective VLP carrier for presenting foreign epitopes, providing a promising platform for epitope-focused vaccine design.

Effects of insect pursuit on the Doppler shift compensation in a hipposiderid bat.

Doppler shift compensation (DSC) is a unique feature observed in certain species of echolocating bats and is hypothesized to be an adaptation to detecting fluttering insects. However, current research on DSC has primarily focused on bats that are not engaged in foraging activities. In this study, we investigated the DSC performance of Pratt's roundleaf bat, Hipposideros pratti, which was trained to pursue insects in various motion states within a laboratory setting. Our study yielded three main results. First, H. pratti demonstrated highly precise DSC during insect pursuit, aligning with previous findings of other flutter-detecting foragers during orientation or landing tasks. Second, we found that the motion state of the insect prey had little effect on the DSC performance of H. pratti. Third, we observed variations in the DSC performance of H. pratti throughout the course of insect pursuit. The bats exhibited the highest DSC performance during the phase of maximum flight speed but decreased performance during the phase of insect capture. These findings of high precision overall and the time-dependent performance of DSC during insect pursuit support the hypothesis that DSC is an adaptation to detecting fluttering insects.

Geographic Variation in Testicular Morphometrics, Androgen Receptor Expression and Anti-Müllerian Hormone Levels in the Intermediate Roundleaf Bats across Distinct Regions in Thailand.

The hipposideros larvatus (intermediate roundleaf bat) is one of the insectivorous bats which has an agro-ecological role as a controller of the insect population. The reproductive patterns of H. larvatus are intricately linked to its ecological role and survival. An understanding of the testicular morphology can contribute to conservation for this species particularly in areas where its populations might be declining or under threat. However, these bats may also be associated with zoonotic diseases which can have significant public health implications. The aims of the study were to examine the morphological data as well as the expression of the androgen receptor (AR) and anti-Müllerian hormone (AMH) in the male reproductive organs of H. larvatus from different areas of Thailand and at different sampling periods. Their testes were processed for histological investigation and immunohistochemistry for AR and AMH. The results showed differences among the various sampling areas and different sampling periods, which suggested seasonal breeding characteristics. The higher testicular morphometric data were observed in H. larvatus from the Dong Phayayen (DY) and Chiang Dao (CD) areas during June, while the size of seminiferous tubules decreased thereafter. High AR immunostaining was noticed when the testicular morphometric data were higher in DY bats during June. On the other hand, low AR was observed in bats during August and September, which was concomitant with the decreases in seminiferous tubule size and germinal epithelial height. The results suggest a potential correlation between AR immunostaining and the active phase of testicular functions in H. larvatus during June which may imply the involvement of AR with the enhancement of testicular activity. Conversely, the low expression of AR may contribute to the upregulation of AMH in the testes and may indicate lower testicular activity in H. larvatus in Thailand.

Surveillance, Isolation, and Genetic Characterization of Bat Herpesviruses in Zambia.

Bats are of significant interest as reservoirs for various zoonotic viruses with high diversity. During the past two decades, many herpesviruses have been identified in various bats worldwide by genetic approaches, whereas there have been few reports on the isolation of infectious herpesviruses. Herein, we report the prevalence of herpesvirus infection of bats captured in Zambia and genetic characterization of novel gammaherpesviruses isolated from striped leaf-nosed bats (Macronycteris vittatus). By our PCR screening, herpesvirus DNA polymerase (DPOL) genes were detected in 29.2% (7/24) of Egyptian fruit bats (Rousettus aegyptiacus), 78.1% (82/105) of Macronycteris vittatus, and one Sundevall's roundleaf bat (Hipposideros caffer) in Zambia. Phylogenetic analyses of the detected partial DPOL genes revealed that the Zambian bat herpesviruses were divided into seven betaherpesvirus groups and five gammaherpesvirus groups. Two infectious strains of a novel gammaherpesvirus, tentatively named Macronycteris gammaherpesvirus 1 (MaGHV1), were successfully isolated from Macronycteris vittatus bats, and their complete genomes were sequenced. The genome of MaGHV1 encoded 79 open reading frames, and phylogenic analyses of the DNA polymerase and glycoprotein B demonstrated that MaGHV1 formed an independent lineage sharing a common origin with other bat-derived gammaherpesviruses. Our findings provide new information regarding the genetic diversity of herpesviruses maintained in African bats.

Diversity of bat ectoparasites from the caves of selected Key Biodiversity Areas in Central Visayas, Philippines

Abstract. Bejec GA, Bucol LA, Ancog AB, Pagente AC, Paneiro JJM, Bejec ALN, Belanizo JD, Tuastomban DJS, Jose RP. 2023. Diversity of bat ectoparasites from the caves of selected Key Biodiversity Areas in Central Visayas, Philippines. Biodiversitas 24(3): 1693-1703. Bats harbor numerous species of ectoparasites, such as ticks and mites. Many bat ectoparasites are implicated as vectors of pathogens ranging from bacteria to protozoa and viruses. Recent studies verified bats as a natural reservoir of multiple zoonotic viruses, including Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) coronaviruses. This study assessed the composition, diversity, and prevalence of ectoparasites of cave-dwelling bats in the four Key Biodiversity Areas (KBAs) of Central Visayas. A total of 20 species of bats were recorded in the 30 surveyed caves. Of these, 30 species of ectoparasites belonging to eight families (dipteran flies Streblidae and Nycteribiidae, mites Spinturnicidae, Macronyssidae and Trombiculidae, ticks Argasidae and Ixodidae, and Ischnopsyllidae fleas) were collected and identified. Leptotrombidium sp. had the highest number of individuals (n=1,684) harbored in 12 bat host species. The highest prevalence (100%) was noted in four bat host species: Philippine pygmy fruit bat Haplonycteris fischeri Lawrence 1939, Philippine forest roundleaf bat Hipposideros obscurus Peters 1861, Philippine pygmy roundleaf batHipposideros pygmaeus Waterhouse 1843, and Common bent-winged bat Miniopterus schreibersii Kuhl 1817. The lowest prevalence was noted in the Round-eared tube-nosed bat Murina cyclotis Dobson 1872, where no ectoparasite was collected. The highest intensity (n=65) of ectoparasites was observed in the Common Asian ghost bat Megaderma spasma Linnaeus 1758. This study provides essential data for future reference in monitoring bat population status and conservation efforts in the region. Given the close relationship between the local human community and bats (e.g., hunting and consumption), more work is needed to address the potential pathogen risks from zoonotic transmission from bats and ectoparasites.

First occurrence record of Indian Roundleaf Bat Hipposideros lankadiva in Rajasthan, India

An erroneously cited text of Wason by subsequent authors has led to the assumption that Hipposideros lankadiva was first recorded in Rajasthan in the Bhim Bharak caves of Jodhpur. A careful review of Wason’s note revealed that it in fact mentioned another species from the genus, H. fulvus. This erroneous citation has led to several research articles published on the ecological aspects of this species to be misinformed. The authors discovered a small population of H. lankadiva in eastern Rajasthan and have monitored this new population since 2010. Since the Bhim Bharak cave location is erroneous, Kased Cave (26.2209N, 77.1024E) is the only location of H. lankadiva for Rajasthan and is therefore the first record of the species from the state.

Role of wing inertia in maneuvering bat flights

The role of aerodynamics and wing inertia on the motion dynamics for the maneuvering flight of two bats from two species of roundleaf bats, H. armiger and H. pratti are investigated. Comparative studies among a straight flight, two ascending sweeping right turns, and a U-turn reveal that inertial forces play an essential and sometimes crucial role in the maneuvers. The translational trajectory of the bat is mostly driven by aerodynamic forces generated by the wings along the flight path, whereas inertial forces for the most part drive the intra-cycle fluctuations. However, inertial forces are found to contribute non-trivially to the ascending motion of the H. armiger during the sweeping turn and the U-turn. The roll maneuver is found to be primarily driven by aerodynamic asymmetries during flight, whereas the yaw maneuver is primarily driven by imbalances in wing inertial moments. Inertial moments resulting from Coriolis and centrifugal forces are found to play an important role in accurate yaw prediction. The moment due to Coriolis force plays a very prominent role in predicting the correct yaw angle during the extreme 180° U-turn.

Genome assembly of the Pendlebury's roundleaf bat, Hipposideros pendleburyi, revealed the expansion of Tc1/Mariner DNA transposons in Rhinolophoidea.

Bats (Chiroptera) constitute the second largest order of mammals and have several distinctive features, such as true self-powered flight and strong immunity. The Pendlebury’s roundleaf bat, Hipposideros pendleburyi, is endemic to Thailand and listed as a vulnerable species. We employed the 10× Genomics linked-read technology to obtain a genome assembly of H. pendleburyi. The assembly size was 2.17 Gb with a scaffold N50 length of 15,398,518 bases. Our phylogenetic analysis placed H. pendleburyi within the rhinolophoid clade of the suborder Yinpterochiroptera. A synteny analysis showed that H. pendleburyi shared conserved chromosome segments (up to 105 Mb) with Rhinolophus ferrumequinum and Phyllostomus discolor albeit having different chromosome numbers and belonging different families. We found positive selection signals in genes involved in inflammation, spermatogenesis and Wnt signalling. The analyses of transposable elements suggested the contraction of short interspersed nuclear elements (SINEs) and the accumulation of young mariner DNA transposons in the analysed hipposiderids. Distinct mariners were likely horizontally transferred to hipposiderid genomes over the evolution of this family. The lineage-specific profiles of SINEs and mariners might involve in the evolution of hipposiderids and be associated with the phylogenetic separations of these bats from other bat families.

Doppler shift compensation performance in Hipposideros pratti across experimental paradigms

A central aim of neuroethological research is to discover the mechanisms of natural behaviors in controlled laboratory studies. This goal, however, comes with challenges, namely the selection of experimental paradigms that allow full expression of natural behaviors. Here, we explore this problem in echolocating bats that evolved Doppler shift compensation (DSC) of sonar vocalizations to yield close matching between echo frequency and hearing sensitivity. We ask if behavioral tasks influence the precision of DSC in Pratt’s roundleaf bat, Hipposideros pratti, in three classic laboratory paradigms evoking audio-vocal adjustments: Stationary bats listening to echo playbacks, bats transported on a moving pendulum, and bats flying freely. We found that experimental conditions had a strong influence on the expression of the audiovocal frequency adjustments in bats. H. pratti exhibited robust DSC in both free-flying and moving-pendulum experiments but did not exhibit consistent audiovocal adjustments in echo playback experiments. H. pratti featured a maximum compensation magnitude of 87% and a compensation precision of 0.27% in the free flight experiment. Interestingly, in the moving pendulum experiment H. pratti displayed surprisingly high-precision DSC, with an 84% maximum compensation magnitude and a 0.27% compensation precision. Such DSC performance places H. pratti among the bat species exhibiting the most precise audio-vocal control of echo frequency. These data support the emerging view that Hipposiderid bats have a high-precision DSC system and highlight the importance of selecting experimental paradigms that yield the expression of robust natural behaviors.

Bats of Mount Silabur, Sarawak, and Its Potential for Conservation

Karst landscape is recognised as one of the biologically important areas especially for bats. The limestone caves and forest within the landscape provide essential resources for the local bat fauna, albeit bat populations are severely threatened by anthropogenic disturbances occurring within and surrounding the ecosystem. In Sarawak, studies on bat diversity are biased towards protected areas, leaving aside non-protected areas including private lands such as Mount Silabur. Surveys on bat diversity were conducted at the limestone outcrop and the surrounding matrix of Mount Silabur with the primary aim of developing the first checklist of bats at Mount Silabur. A total of 27 species were recorded from 12 sampling nights representing approximately 34% of the total bat species recorded in Sarawak. The Cox’s Roundleaf Bat (Hipposideros coxi), a rare Bornean endemic species, was recorded from the cave system, signifying an important record for the area and also Sarawak. Furthermore, this is the sixth locality record for the species in Sarawak, Borneo. Interestingly, the total number of bat species recorded from Mount Silabur represented about 72% of the total bat species recorded (27 out of 38 species) from other major touristic caves in western Sarawak; Fairy Cave Nature Reserve and Wind Cave Nature Reserve. This warrants a need to develop an action plan to protect and conserve Mount Silabur cave system and the surrounding forest for its potential to serve as a shelter for bats and other cave and forest dependent taxa. The local community should implement and adhere to guidelines for cave related activities to minimise human driven disturbances on the ecosystem and its inhabitants.

The virome of the white-winged vampire bat Diaemus youngi is rich in circular DNA viruses.

In the Neotropical region, the white-winged vampire bat (Diaemus youngi) is the rarest of the three species of vampire bats. This bat species feeds preferentially on bird blood, and there is limited information on the viruses infecting D. youngi. Hence, this study aimed to expand the knowledge about the viral diversity associated with D. youngi by sampling and pooling the lungs, liver, kidneys, heart, and intestines of all animals using high-throughput sequencing (HTS) on the Illumina MiSeq platform. A total of three complete and 10 nearly complete circular virus genomes were closely related to gemykrogvirus (Genomoviridae family), smacovirus (Smacoviridae family), and torque teno viruses (TTVs) (Anelloviridae family). In addition, three sequences of bat paramyxovirus were detected and found to be closely related to viruses reported in Pomona roundleaf bats and rodents. The present study provides a snapshot of the viral diversity associated with white-winged vampire bats and provides a baseline for comparison to viruses detected in future outbreaks. Supplementary InformationThe online version contains supplementary material available at 10.1007/s11262-022-01897-6.

Development of an in vitro model for animal species susceptibility to SARS-CoV-2 replication based on expression of ACE2 and TMPRSS2 in avian cells.

The SARS-CoV-2 (SARS-CoV-2) virus has caused a worldwide pandemic because of the virus's ability to transmit efficiently human-to-human. A key determinant of infection is the attachment of the viral spike protein to the host receptor angiotensin-converting enzyme 2 (ACE2). Because of the presumed zoonotic origin of SARS-CoV-2, there is no practical way to assess the susceptibility of every species to SARS-CoV-2 by direct challenge studies. In an effort to have a better predictive model of animal host susceptibility to SARS-CoV-2, we expressed the ACE2 and/or transmembrane serine protease 2 (TMPRSS2) genes from humans and other animal species in the avian fibroblast cell line, DF1, that is not permissive to infection. We demonstrated that expression of both human ACE2 and TMPRSS2 genes is necessary to support SARS-CoV-2 infection and replication in DF1 and a non-permissive sub-lineage of MDCK cells. Titers of SARS-CoV-2 in these cell lines were comparable to those observed in control Vero cells. To further test the model, we developed seven additional transgenic cell lines expressing the ACE2 and TMPRSS2 derived from Felis catus (cat), Equus caballus (horse), Sus domesticus (pig), Capra hircus (goat), Mesocricetus auratus (Golden hamster), Myotis lucifugus (Little Brown bat) and Hipposideros armiger (Great Roundleaf bat) in DF1 cells. Results demonstrate permissive replication of SARS-CoV-2 in cat, Golden hamster, and goat species, but not pig or horse, which correlated with the results of reported challenge studies. Cells expressing genes from either bat species tested demonstrated temporal replication of SARS-CoV-2 that peaked early and was not sustained. The development of this cell culture model allows for more efficient testing of the potential susceptibility of many different animal species for SARS-CoV-2 and emerging variant viruses.

Bats avoid overheating through intermittent flying

Bats are remarkably versatile. Not only are they the sole mammal that has mastered the mystery of flight but they also have the ability to lower their body temperature to reduce their metabolic rate and conserve energy when the temperature drops. However, when bats are flying, their metabolic rate is considerably higher, causing their body temperature to rise. Yet, little is known about how bats prevent themselves from overheating during flight. Jinhong Luo from the Central China Normal University, China, Stefan Greif and Yossi Yovel from Tel Aviv University, Israel, and colleagues from Israel and Thailand, decided to monitor the body temperature of wild great roundleaf bats (Hipposideros armiger), which is one of the largest insect-eating bats, taking short intermittent breaks between flights while they hunt at night for moths, butterflies and beetles.The team went out to Satun cave in Thailand and caught 18 bats using hand nets. Then, they attached a small temperature and motion sensor equipped with a GPS tracker to the backs of 10 bats, gently inserting the tiny temperature sensor beneath the skin to simultaneously record their temperature as they flew at night. Ten days later, the team successfully relocated five of the original sensors by following the GPS signal, discovering that four had successfully recorded the bats’ body temperature, although only two of the motion sensors clearly showed their flight manoeuvres. In addition, the team tagged the eight remaining bats with the temperature and motion sensors alone and released the animals in a 3×2×2 m3 room, letting them fly freely to collect more detailed information about the mammal's flight manoeuvres and body temperature. Once the experiments were complete, the team removed the tags, and re-released the bats into the wild.After analysing the movements of the bats that had spent time in the laboratory, the team identified 55 flight bouts that lasted for about 48 s. Between these short flights, the bats would stop flying and take breaks on perches. The researchers then compared their activities with the skin temperature measurements and found that the bats that had experienced the fastest skin temperature rises had the highest skin temperatures, while the bats that had slower temperature rises ended up with cooler skins. The researchers then compared those findings with the situation of the bats in the wild and found a similar skin temperature pattern. Also, when the team checked the highest skin temperatures of both groups of bats, they reached approximately 40°C, fortunately well below the lethal level of 44–45°C.The researchers suspect that the short intermittent flights used by the hunting bats may help the animals to avoid potentially lethally high body temperatures. Additionally, when great roundleaf bats take breaks on a perch between foraging bouts, the bats probably reduce the amount of energy that they use, compared with the amount of energy they would consume if continually flying and searching for prey. Now that Luo, Greif and colleagues have successfully measured the skin temperature of wild flying great roundleaf bats, other researchers could use the same strategy to find out how bats that thrive on different diets, such as fruit or even scorpions, keep their temperature down when performing the most metabolically demanding activity known. Alternatively, scientists could look at the body temperature of smaller bats as they go about catching insects, to find out how body size impacts how they regulate their temperature while on the wing.

Notes on roundleaf bats (Hipposideridae) at selected forest reserves of Central Forest Spine (CFS) landscapes in Peninsular Malaysia

Surveys on Roundleaf bats (Hipposideridae) were conducted at 18 forest reserves in nine CFS ecological corridor networks namely Pedu, Bukit Saiong, Kenderong, Bintang Hijau, Sungai Betis, Sungai Brok, Tembat, Tanum, Sungai Yu, Ulu Jelai, Bukit Bujang, Angsi, Berembun, Labis Timur, Mersing, Lenggor Tengah, Panti and Ulu Sedili FRs. This study mainly aims to record the presence of Hipposideridae at the selected forest reserves. The surveys started from February 2018 until August 2020. A total of three harp traps were set up in each forest reserve, except for Ulu Jelai, Tembat and Berembun FRs with six harp traps. Overall, 67 individuals comprising seven species from genus Hipposideros were recorded in this study. Hipposideros bicolor was the most widely distributed species recorded in nine forest reserves whereas, Hipposideros larvatus is the most abundance species recorded in this study with 25 individuals. Kenderong and Bintang Hijau FRs recorded the highest number of Hipposideridae species in this study, both with four species. The presence of Hipposiderids in this study might be associated with their suitable roosting and foraging areas as well as availability of food sources. Therefore, this information gives an early insight on Hipposideridae distribution and habitat requirement at the forest reserves in CFS ecological corridor landscapes that stakeholders need to consider in establishing the corridors. More sampling efforts need to put in this study, covering more areas in the forest reserves with longer sampling periods and more number of traps used in order to really identify critical corridors for bat conservations.

Analysis of a 180-degree U-turn maneuver executed by a hipposiderid bat.

Bats possess wings comprised of a flexible membrane and a jointed skeletal structure allowing them to execute complex flight maneuvers such as rapid tight turns. The extent of a bat's tight turning capability can be explored by analyzing a 180-degree U-turn. Prior studies have investigated more subtle flight maneuvers, but the kinematic and aerodynamic mechanisms of a U-turn have not been characterized. In this work, we use 3D optical motion capture and aerodynamic simulations to investigate a U-turn maneuver executed by a great roundleaf bat (Hipposideros armiger: mass = 55 g, span = 51 cm). The bat was observed to decrease its flight velocity and gain approximately 20 cm of altitude entering the U-turn. By lowering its velocity from 2.0 m/s to 0.5 m/s, the centripetal force requirement to execute a tight turn was substantially reduced. Centripetal force was generated by tilting the lift force vector laterally through banking. During the initiation of the U-turn, the bank angle increased from 20 degrees to 40 degrees. During the initiation and persisting throughout the U-turn, the flap amplitude of the right wing (inside of the turn) increased relative to the left wing. In addition, the right wing moved more laterally closer to the centerline of the body during the end of the downstroke and the beginning of the upstroke compared to the left wing. Reorientation of the body into the turn happened prior to a change in the flight path of the bat. Once the bat entered the U-turn and the bank angle increased, the change in flight path of the bat began to change rapidly as the bat negotiated the apex of the turn. During this phase of the turn, the minimum radius of curvature of the bat was 5.5 cm. During the egress of the turn, the bat accelerated and expended stored potential energy by descending. The cycle averaged total power expenditure by the bat during the six wingbeat cycle U-turn maneuver was 0.51 W which was approximately 40% above the power expenditure calculated for a nominally straight flight by the same bat. Future work on the topic of bat maneuverability may investigate a broader array of maneuvering flights characterizing the commonalities and differences across flights. In addition, the interplay between aerodynamic moments and inertial moments are of interest in order to more robustly characterize maneuvering mechanisms.

An experimental link between fast noseleaf deformations and biosonar pulse dynamics in hipposiderid bats

Old-World leaf-nosed bats (Hipposideridae) are echolocating bats with peculiar emission-side dynamics where beamforming baffles ("noseleaves") that surround the points of ultrasound emission (nostrils) change shape while diffracting the outgoing biosonar pulses. While prior work with numerical and robotic models has suggested that these noseleaf deformations could have an impact on the output characteristics of the bat's biosonar system, testing the hypothesis that this is the case in bats remains a critical step to be taken. The work presented here has tested the hypothesis that the noseleaf dynamics in a species of hipposiderid bat (Pratt's roundleaf bat, H. pratti) leads to time-variant acoustical properties on the output side of the bats' biosonar emission system. The time-variant effects of the noseleaf motion could be detected even in the presence of other sources of variability by comparing the distribution of pulse energy over the angle at different points in time. Furthermore, a convolutional neural network was able to classify the noseleaf motion state based on microphone array recordings with 85.3% accuracy. These results hence demonstrate that these nose-emitting bats have access to a substrate for behavioral flexibility on the emission-side of their biosonar systems.

Great roundleaf bats coordinate noseleaf and ear gyrations

![Graphic][1] Listening for the returning sound of your own echoing voice is always entertaining, but the echoes produced by cruising bats are more than a simple amusement. Guiding the nocturnal creatures past obstacles, the tiny mammals’ high-pitched calls also allow them to pinpoint tasty

Novel Bat Alphacoronaviruses in Southern China Support Chinese Horseshoe Bats as an Important Reservoir for Potential Novel Coronaviruses.

While bats are increasingly recognized as a source of coronavirus epidemics, the diversity and emergence potential of bat coronaviruses remains to be fully understood. Among 1779 bat samples collected in China, diverse coronaviruses were detected in 32 samples from five different bat species by RT-PCR. Two novel alphacoronaviruses, Rhinolophus sinicus bat coronavirus HKU32 (Rs-BatCoV HKU32) and Tylonycteris robustula bat coronavirus HKU33 (Tr-BatCoV HKU33), were discovered from Chinese horseshoe bats in Hong Kong and greater bamboo bats in Guizhou Province, respectively. Genome analyses showed that Rs-BatCoV HKU32 is closely related to BatCoV HKU10 and related viruses from diverse bat families, whereas Tr-BatCoV HKU33 is closely related to BtNv-AlphaCoV and similar viruses exclusively from bats of Vespertilionidae family. The close relatedness of Rs-BatCoV HKU32 to BatCoV HKU10 which was also detected in Pomona roundleaf bats from the same country park suggests that these viruses may have the tendency of infecting genetically distant bat populations of close geographical proximity with subsequent genetic divergence. Moreover, the presence of SARSr-CoV ORF7a-like protein in Rs-BatCoV HKU32 suggests a common evolutionary origin of this accessory protein with SARS-CoV, also from Chinese horseshoe bats, an apparent reservoir for coronavirus epidemics. The emergence potential of Rs-BatCoV HKU32 should be explored.

A unique B cell epitope-based particulate vaccine shows effective suppression of hepatitis B surface antigen in mice

ObjectiveThis study aimed to develop a novel therapeutic vaccine based on a unique B cell epitope and investigate its therapeutic potential against chronic hepatitis B (CHB) in animal models.MethodsA series...