Improved chaotic Bat algorithm for optimal coordinated tuning of power system stabilizers for multimachine power system.

Power systems exhibit nonlinearity. causing dynamic instability and complex power oscillations. This research proposes an innovative strategy using the Novel Bat Algorithm (NBA) to achieve ideal Power System Stabilizers (PSSs) in a multimachine power system. The approach shifts electromechanical modes to specific areas in the s-plane. Enhancing the multi-machine power system and establishing stabilizer parameters for dynamic performance. The study examines the designed approach aptitude for standard lead-lag PSSs configurations. In order to elevate the global search problem and transfer some static operators for the optimum optimization process. the chaos mapping. also known as CNBA. is introduced into NBA. Four different forms of chaos maps are compared in experiments to resolve unconstrained mathematical issues in order to illustrate CNBA performance. In any other case. the challenge of designing PSS under a wide range of loading situations is transformed into an optimization challenge with the damping ratio of electromechanical modes with low damping as the target function. The optimal stabilizers' gains are gotten by employing the CNBA algorithm. Second plan. an effective technique is astutely established to delineate the PSS location and quantity using CNBA and another side using participation factor. To examine the efficacy of the proposed CNBA-based PSS on a large system; it is tested on the interconnected of New-England/New-York (16 generators and 68 buses) power grid. and verified by comparative study with NBA through eigenvalue analysis and nonlinear simulation to provide evidence the algorithmic competence of CNBA. The CNBA approach yields a minimum damping ratio of 37%. which is consistent with the its eigenvalue. In contrast, the NBA approach achieves a minimum damping ratio of 31%. The simulation results reveal the fine performance of the proposed CNBA-PSS in a convincing manner and its capacity to provide an excellent damping for inter-area and local oscillations under diverse operating cases compared to NBA-PSS then in the case of PSS location.

Adipose Tissue Dysfunction Related to Climate Change and Air Pollution: Understanding the Metabolic Consequences.

Obesity, a global pandemic, poses a major threat to healthcare systems worldwide. Adipose tissue, the energy-storing organ during excessive energy intake, functions as a thermoregulator, interacting with other tissues to regulate systemic metabolism. Specifically, brown adipose tissue (BAT) is positively associated with an increased resistance to obesity, due to its thermogenic function in the presence of uncoupled protein 1 (UCP1). Recently, studies on climate change and the influence of environmental pollutants on energy homeostasis and obesity have drawn increasing attention. The reciprocal relationship between increasing adiposity and increasing temperatures results in reduced adaptive thermogenesis, decreased physical activity, and increased carbon footprint production. In addition, the impact of climate change makes obese individuals more prone to developing type 2 diabetes mellitus (T2DM). An impaired response to heat stress, compromised vasodilation, and sweating increase the risk of diabetes-related comorbidities. This comprehensive review provides information about the effects of climate change on obesity and adipose tissue, the risk of T2DM development, and insights into the environmental pollutants causing adipose tissue dysfunction and obesity. The effects of altered dietary patterns on adiposity and adaptation strategies to mitigate the detrimental effects of climate change are also discussed.

Exploring People's Perception on Pros and Cons of Human-Bat Coexistence in Urban Environs in Southwestern Nigeria.

This research intricately explores the dynamics surrounding the coexistence of humans and roosting bats in urban areas, meticulously examining both the advantageous and detrimental aspects of their living arrangement. The study conducted a comprehensive survey with 286 residents in Iwo and Ogbomoso, where Eidolon helvum bats are known to roost, generating a robust dataset for thorough analysis. Rigorous statistical assessments, including the KMO and Bartlett's tests, confirmed the data's reliability at a significance level of P < .05. The respondent demographic revealed a predominance of 65% male participants, with an overwhelming 85% claiming familiarity with bats in their respective domains. Utilizing factor analysis, the study identified 8 salient variables from the initial 26, shedding light on diverse perceptions regarding bats: (i) Urban roosting (16.729%); (ii) Impact on tree growth (12.607%); (iii) Failed dislodgement attempts (11.504%); (iv) Medicinal value (10.240%); (v) Co-habitation preference (9.963%); (vi) Costly dislodgment consequences (9.963%); (vii) Beautification disruption (5.615%); and (viii) Structure defacement (5.510%). These factors were systematically categorized into 4 distinct themes: (A) Forced cohabitation (26.762%); (B) Environmental degradation by bats (23.732%); (C) Consequences of dislodging bats (21.477%); and (D) Acknowledged benefits of bats (10.240%). Co-habitation with bats becomes a necessity for ecological balance and, importantly, to safeguard the livelihood of roosting bats within their natural ecology, which man has encroached upon through urbanization, making all negatives arising from such existence self-inflicted by man. However, this study underscores the importance of human-bat cohabitation for mutual benefits, emphasizing potential detrimental consequences, including significant costs, associated with displacing bats from their natural ecosystem. These consequences may exacerbate the impacts of climate change, environmental degradation, and ecological imbalance. Further research is recommended to explore the positive aspects of the sustainable roosting bats' existence in the natural environment.

Zoonotic assemblages A and B of Giardia duodenalis in Chiroptera from Brazilian Amazon biome.

Bats are important reservoirs and spreaders of pathogens. Giardia duodenalis is a globally important protozoan that infects humans and other mammals with considerable public health burden, particularly on the child development. Based on genetic variation and host specificity, G. duodenalis is categorized into eight genotypes/assemblages A-H. Assemblages A and B are widespread globally and are associated with human and animal disease. There is evidence of Giardia in the bat feces from diverse geographic regions, but the G. duodenalis assemblages are unknown, which is a key point for the One Health view. Here, we successfully amplified the BG/GDH/DIS3/HCMP2/HCMP3 targets of G. duodenalis from five bat species captured in the Brazilian Amazon biome revealing the presence of zoonotic G. duodenalis assemblages A and B in the feces of these flying mammals. Our study reveals that bats may play a role in transmission of zoonotic G. duodenalis, at least in this biome.

A wingless fly on a winged mammal: host-parasite dynamics between Basilia travassosi (Diptera: Nycteribiidae) and Myotis lavali (Chiroptera: Vespertilionidae).

Nycteribiidae encompasses a specialized group of wingless blood-sucking flies that parasitize bats worldwide. Such relationships are frequently species- or genus-specific, indicating unique eco-evolutionary processes. However, despite this significance, comprehensive studies on the relationships of these flies with their hosts, particularly in the New World, have been scarce. Here, we provide a detailed description of the parasitological patterns of nycteribiid flies infesting a population of Myotis lavali bats in the Atlantic Forest of northeastern Brazil, considering the potential influence of biotic and abiotic factors on the establishment of nycteribiids on bat hosts. From July 2014 to June 2015, we captured 165 M. lavali bats and collected 390 Basilia travassosi flies. Notably, B. travassosi displayed a high prevalence and was the exclusive fly species parasitizing M. lavali in the surveyed area. Moreover, there was a significant predominance of female flies, indicating a female-biased pattern. The distribution pattern of the flies was aggregated; most hosts exhibited minimal or no parasitism, while a minority displayed heavy infestation. Sexually active male bats exhibited greater susceptibility to parasitism compared to their inactive counterparts, possibly due to behavioral changes during the peak reproductive period. We observed a greater prevalence and abundance of flies during the rainy season, coinciding with the peak reproductive phase of the host species. No obvious correlation was observed between the parasite load and bat body mass. Our findings shed light on the intricate dynamics of nycteribiid-bat interactions and emphasize the importance of considering various factors when exploring bat-parasite associations.

Torpor use in the wild by one of the world's largest bats.

Torpor is widespread among bats presumably because most species are small, and torpor greatly reduces their high mass-specific resting energy expenditure, especially in the cold. Torpor has not been recorded in any bat species larger than 50 g, yet in theory could be beneficial even in the world's largest bats (flying-foxes; Pteropus spp.) that are exposed to adverse environmental conditions causing energy bottlenecks. We used temperature telemetry to measure body temperature in wild-living adult male grey-headed flying-foxes (P. poliocephalus; 799 g) during winter in southern Australia. We found that all individuals used torpor while day-roosting, with minimum body temperature reaching 27°C. Torpor was recorded following a period of cool, wet and windy weather, and on a day with the coldest maximum air temperature, suggesting it is an adaptation to reduce energy expenditure during periods of increased thermoregulatory costs and depleted body energy stores. A capacity for torpor among flying-foxes has implications for understanding their distribution, behavioural ecology and life history. Furthermore, our discovery increases the body mass of bats known to use torpor by more than tenfold and extends the documented use of this energy-saving strategy under wild conditions to all bat superfamilies, with implications for the evolutionary maintenance of torpor among bats and other mammals.

Full-genome sequencing of dozens of new DNA viruses found in Spanish bat feces.

Bats are natural hosts of multiple viruses, many of which have clear zoonotic potential. The search for emerging viruses has been aided by the implementation of metagenomic tools, which have also enabled the detection of unprecedented viral diversity. Currently, this search is mainly focused on RNA viruses, which are largely over-represented in databases. To compensate for this research bias, we analyzed fecal samples from 189 Spanish bats belonging to 22 different species using viral metagenomics. This allowed us to identify 52 complete or near-complete viral genomes belonging to the families Adenoviridae, Circoviridae, Genomoviridae, Papillomaviridae, Parvoviridae, Polyomaviridae and Smacoviridae. Of these, 30 could constitute new species, doubling the number of viruses currently described in Europe. These findings open the door to a more thorough analysis of bat DNA viruses and their zoonotic potential. IMPORTANCE: Metagenomics has become a fundamental tool to characterize the global virosphere, allowing us not only to understand the existing viral diversity and its ecological implications but also to identify new and emerging viruses. RNA viruses have a higher zoonotic potential, but this risk is also present for some DNA virus families. In our study, we analyzed the DNA fraction of fecal samples from 22 Spanish bat species, identifying 52 complete or near-complete genomes of different viral families with zoonotic potential. This doubles the number of genomes currently described in Europe. Metagenomic data often produce partial genomes that can be difficult to analyze. Our work, however, has characterized a large number of complete genomes, thus facilitating their taxonomic classification and enabling different analyses to be carried out to evaluate their zoonotic potential. For example, recombination studies are relevant since this phenomenon could play a major role in cross-species transmission.

Legume Allergens Pea, Chickpea, Lentil, Lupine and Beyond.

PURPOSE OF THE REVIEW: In the last decade, an increasing trend towards a supposedly healthier vegan diet could be observed. However, recently, more cases of allergic reactions to plants and plant-based products such as meat-substitution products, which are often prepared with legumes, were reported. Here, we provide the current knowledge on legume allergen sources and the respective single allergens. We answer the question of which legumes beside the well-known food allergen sources peanut and soybean should be considered for diagnostic and therapeutic measures. RECENT FINDINGS: These "non-priority" legumes, including beans, pea, lentils, chickpea, lupine, cowpea, pigeon pea, and fenugreek, are potentially new important allergen sources, causing mild-to-severe allergic reactions. Severe reactions have been described particularly for peas and lupine. An interesting aspect is the connection between anaphylactic reactions and exercise (food-dependent exercise-induced anaphylaxis), which has only recently been highlighted for legumes such as soybean, lentils and chickpea. Most allergic reactions derive from IgE cross-reactions to homologous proteins, for example between peanut and lupine, which is of particular importance for peanut-allergic individuals ignorant to these cross-reactions. From our findings we conclude that there is a need for large-scale studies that are geographically distinctive because most studies are case reports, and geographic differences of allergic diseases towards these legumes have already been discovered for well-known "Big 9" allergen sources such as peanut and soybean. Furthermore, the review illustrates the need for a better molecular diagnostic for these emerging non-priority allergen sources to evaluate IgE cross-reactivities to known allergens and identify true allergic reactions.

Unraveling genomic features and phylogenomics through the analysis of three Mexican endemic Myotis genomes.

Background: Genomic resource development for non-model organisms is rapidly progressing, seeking to uncover molecular mechanisms and evolutionary adaptations enabling thriving in diverse environments. Limited genomic data for bat species hinder insights into their evolutionary processes, particularly within the diverse Myotis genus of the Vespertilionidae family. In Mexico, 15 Myotis species exist, with three-M. vivesi, M. findleyi, and M. planiceps-being endemic and of conservation concern. Methods: We obtained samples of Myotis vivesi, M. findleyi, and M. planiceps for genomic analysis. Each of three genomic DNA was extracted, sequenced, and assembled. The scaffolding was carried out utilizing the M. yumanensis genome via a genome-referenced approach within the ntJoin program. GapCloser was employed to fill gaps. Repeat elements were characterized, and gene prediction was done via ab initio and homology methods with MAKER pipeline. Functional annotation involved InterproScan, BLASTp, and KEGG. Non-coding RNAs were annotated with INFERNAL, and tRNAscan-SE. Orthologous genes were clustered using Orthofinder, and a phylogenomic tree was reconstructed using IQ-TREE. Results: We present genome assemblies of these endemic species using Illumina NovaSeq 6000, each exceeding 2.0 Gb, with over 90% representing single-copy genes according to BUSCO analyses. Transposable elements, including LINEs and SINEs, constitute over 30% of each genome. Helitrons, consistent with Vespertilionids, were identified. Values around 20,000 genes from each of the three assemblies were derived from gene annotation and their correlation with specific functions. Comparative analysis of orthologs among eight Myotis species revealed 20,820 groups, with 4,789 being single copy orthogroups. Non-coding RNA elements were annotated. Phylogenomic tree analysis supported evolutionary chiropterans' relationships. These resources contribute significantly to understanding gene evolution, diversification patterns, and aiding conservation efforts for these endangered bat species.

Investigation of Rabies virus in wild mammals of the atlantic forest in Rio de Janeiro, Brazil.

With the successful control of rabies transmitted by dogs in Brazil, wild animals have played a relevant epidemiological role in the transmission of rabies virus (RABV). Bats, non-human primates and wild canines are the main wild animals that transmit RABV in the country. It is worth highlighting the possibility of synanthropic action of these species, when they become adapted to urban areas, causing infections in domestic animals and eventually in humans. This work aimed to evaluate the circulation of RABV in the Pedra Branca Forest, an Atlantic Forest area, located in the state of Rio de Janeiro, Southeast Brazil. Saliva and blood samples were obtained from 60 individuals of eight species of bats, captured with mist nets, and 13 individuals of callitrichid primates, captured with tomahawk traps. Saliva samples were subjected to Reverse Transcription Polymerase Chain Reaction (RT-PCR), targeting the RABV N gene, with all samples being negative. Blood samples of all animals were submitted to the Rapid Fluorescent Focus Inhibition Test (RFFIT) to detect neutralizing antibodies (Ab) for RABV. Six bat samples (8%) were seropositive for RABV with antibody titers greater than or equal to 0.1 IU/mL. The detection of Ab but not viral RNA indicates exposure rather than current RABV transmission in the analyzed populations. The results presented here reinforce the importance of serological studies in wildlife to access RABV circulation in a region.

Depletion of JunB increases adipocyte thermogenic capacity and ameliorates diet-induced insulin resistance.

Adipose tissue is a crucial metabolic organ in the human body. It stores and exerts distinct physiological functions in different body regions. Fat not only serves as a cushion and insulator but also stores energy and conveys endocrine signals within the body. There is a growing recognition that adipose tissue is an organ that is misunderstood and underestimated in contribution to human health and disease progression by regulating its size and functionality. In mammals, the adipose tissue reservoir consists of three functionally distinct types of fat: white adipose tissue (WAT), brown adipose tissue (BAT), and beige or inducible brown adipose tissue (iWAT), which exhibits thermogenic capabilities intermediate between the other two. Fat in different depots exhibits considerable differences in origin, characteristics, and functions. They vary not only in adipocyte lineage, properties, thermogenesis, and endocrine functions but also in their immunological functions. In a recent study published in Nature Metabolism, Zhang et al. investigated the role of JunB in the thermogenic capacity of adipocytes and its significance in obesity and metabolic disorders. The study revealed that JunB expression in BAT coexists with both low and high thermogenic adipocytes, indicating a fundamental feature of heterogeneity and plasticity within BAT. In summary, this article demonstrates that research targeting JunB holds promise for improving diet-induced obesity and insulin resistance, offering new avenues for treating metabolic disorders.

Myotis bat STING attenuates aging-related inflammation in female mice.

Bats, notable as the only flying mammals, serve as natural reservoir hosts for various highly pathogenic viruses in humans (e.g., SARS-CoV and Ebola virus). Furthermore, bats exhibit an unparalleled longevity among mammals relative to their size, particularly the Myotis bats, which can live up to 40 years. However, the mechanisms underlying these distinctive traits remain incompletely understood. In our prior research, we demonstrated that bats exhibit dampened STING-interferon activation, potentially conferring upon them the capacity to mitigate virus- or aging-induced inflammation. To substantiate this hypothesis, we established the first in vivo bat-mouse model for aging studies by integrating Myotis davidii bat STING ( MdSTING) into the mouse genome. We monitored the genotypes of these mice and performed a longitudinal comparative transcriptomic analysis on MdSTING and wild-type mice over a 3-year aging process. Blood transcriptomic analysis indicated a reduction in aging-related inflammation in female MdSTING mice, as evidenced by significantly lower levels of pro-inflammatory cytokines and chemokines, immunopathology, and neutrophil recruitment in aged female MdSTING mice compared to aged wild-type mice in vivo. These results indicated that MdSTING knock-in attenuates the aging-related inflammatory response and may also improve the healthspan in mice in a sex-dependent manner. Although the underlying mechanism awaits further study, this research has critical implications for bat longevity research, potentially contributing to our comprehension of healthy aging in humans.

Little Brown Bats (Myotis lucifugus) Are Resistant to SARS-CoV-2 Infection.

It has been proposed that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that spread through human populations as a pandemic originated in Asian bats. There is concern that infected humans could transmit the virus to native North American bats; therefore, the susceptibility of several North American bat species to the pandemic virus has been experimentally assessed. Big brown bats (Eptesicus fuscus) were shown to be resistant to infection by SARS-CoV-2, whereas Mexican free-tailed bats (Tadarida brasiliensis) became infected and orally excreted moderate amounts of virus for up to 18 d postinoculation. Little brown bats (Myotis lucifugus) frequently contact humans, and their populations are threatened over much of their range due to white-nose syndrome, a fungal disease that is continuing to spread across North America. We experimentally challenged little brown bats with SARS-CoV-2 to determine their susceptibility and host potential and whether the virus presents an additional risk to this species. We found that this species was resistant to infection by SARS-CoV-2. These findings provide reassurance to wildlife rehabilitators, biologists, conservation scientists, and the public at large who are concerned with possible transmission of this virus to threatened bat populations.

Multi-omic analysis of bat versus human fibroblasts reveals altered central metabolism.

Bats have unique characteristics compared to other mammals, including increased longevity and higher resistance to cancer and infectious disease. While previous studies have analyzed the metabolic requirements for flight, it is still unclear how bat metabolism supports these unique features, and no study has integrated metabolomics, transcriptomics, and proteomics to characterize bat metabolism. In this work, we performed a multi-omics data analysis using a computational model of metabolic fluxes to identify fundamental differences in central metabolism between primary lung fibroblast cell lines from the black flying fox fruit bat (Pteropus alecto) and human. Bat cells showed higher expression levels of Complex I components of electron transport chain (ETC), but, remarkably, a lower rate of oxygen consumption. Computational modeling interpreted these results as indicating that Complex II activity may be low or reversed, similar to an ischemic state. An ischemic-like state of bats was also supported by decreased levels of central metabolites and increased ratios of succinate to fumarate in bat cells. Ischemic states tend to produce reactive oxygen species (ROS), which would be incompatible with the longevity of bats. However, bat cells had higher antioxidant reservoirs (higher total glutathione and higher ratio of NADPH to NADP) despite higher mitochondrial ROS levels. In addition, bat cells were more resistant to glucose deprivation and had increased resistance to ferroptosis, one of the characteristics of which is oxidative stress. Thus, our studies revealed distinct differences in the ETC regulation and metabolic stress responses between human and bat cells.

The genome sequence of the Brown Long-eared bat, Plecotus auritus (Linnaeus 1758).

We present a genome assembly from a female Plecotus auritus (Brown Long-eared bat; Chordata; Mammalia; Chiroptera; Vespertilionidae). The genome sequence is 2163.2 megabases in span. Most of the assembly is scaffolded into 16 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 16.91 kilobases in length.

Prevalence and Genetic Diversity of Bat Hepatitis B Viruses in Bat Species Living in Gabon.

Hepatitis B virus (HBV) infection leads to around 800,000 deaths yearly and is considered to be a major public health problem worldwide. However, HBV origins remain poorly understood. Here, we looked for bat HBV (BtHBV) in different bat species in Gabon to investigate the role of these animals as carriers of ancestral hepadnaviruses because these viruses are much more diverse in bats than in other host species. DNA was extracted from 859 bat livers belonging to 11 species collected in caves and villages in the southeast of Gabon and analyzed using PCRs targeting the surface gene. Positive samples were sequenced using the Sanger method. BtHBV DNA was detected in 64 (7.4%) individuals belonging to eight species mainly collected in caves. Thirty-six (36) sequences among the 37 obtained after sequencing were phylogenetically close to the RBHBV strain recently isolated in Gabonese bats, while the remaining sequence was close to a rodent HBV strain isolated in America. The generalized linear mixed model showed that the variable species best explained the occurrence of BtHBV infection in bats. The discovery of a BtHBV strain homologous to a rodent strain in bats raises the possibility that these animals may be carriers of ancestral hepadnaviruses.

Comparative Proteomics and Interactome Analysis of the SARS-CoV-2 Nucleocapsid Protein in Human and Bat Cell Lines.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of COVID-19 and responsible for the global coronavirus pandemic which started in 2019. Despite exhaustive efforts to trace its origins, including potential links with pangolins and bats, the precise origins of the virus remain unclear. Bats have been recognized as natural hosts for various coronaviruses, including the Middle East respiratory coronavirus (MERS-CoV) and the SARS-CoV. This study presents a comparative analysis of the SARS-CoV-2 nucleocapsid protein (N) interactome in human and bat cell lines. We identified approximately 168 cellular proteins as interacting partners of SARS-CoV-2 N in human cells and 196 cellular proteins as interacting partners with this protein in bat cells. The results highlight pathways and events that are both common and unique to either bat or human cells. Understanding these interactions is crucial to comprehend the reasons behind the remarkable resilience of bats to viral infections. This study provides a foundation for a deeper understanding of host-virus interactions in different reservoirs.

A chemo-mechanical constitutive model for muscle activation in bat wing skins.

Birds, bats and insects have evolved unique wing structures to achieve a wide range of flight capabilities. Insects have relatively stiff and passive wings, birds have a complex and hierarchical feathered structure and bats have an articulated skeletal system integrated with a highly stretchable skin. The compliant skin of the wing distinguishes bats from all other flying animals and contributes to bats' remarkable, highly manoeuvrable flight performance and high energetic efficiency. The structural and functional complexity of the bat wing skin is one of the least understood although important elements of the bat flight anatomy. The wing skin has two unusual features: a discrete array of very soft elastin fibres and a discrete array of skeletal muscle fibres. The latter is intriguing because skeletal muscle is typically attached to bone, so the arrangement of intramembranous muscle in soft skin raises questions about its role in flight. In this paper, we develop a multi-scale chemo-mechanical constitutive model for bat wing skin. The chemo-mechanical model links cross-bridge cycling to a structure-based continuum model that describes the active viscoelastic behaviour of the soft anisotropic skin tissue. Continuum models at the tissue length-scale are valuable as they are easily implemented in commercial finite element codes to solve problems involving complex geometries, loading and boundary conditions. The constitutive model presented in this paper will be used in detailed finite element simulations to improve our understanding of the mechanics of bat flight in the context of wing kinematics and aerodynamic performance.

Detection and Serological Evidence of European Bat Lyssavirus 1 in Belgian Bats between 2016 and 2018.

Lyssaviruses are neurotropic viruses capable of inducing fatal encephalitis. While rabies virus has been successfully eradicated in Belgium, the prevalence of other lyssaviruses remains uncertain. In this study, we conducted a survey on live animals and passive surveillance to investigate the presence of lyssaviruses in Belgium. In 2018, a total of 113 saliva samples and 87 blood samples were collected from bats. Saliva was subjected to RT-qPCR to identify lyssavirus infections. Additionally, an adapted lyssavirus neutralisation assay was set up for the detection of antibodies neutralising EBLV-1 in blood samples. Furthermore, we examined 124 brain tissue samples obtained from deceased bats during passive surveillance between 2016 and 2018. All saliva samples tested negative for lyssaviruses. Analysis of the blood samples uncovered the presence of lyssavirus-neutralising antibodies in five bat species and 32% of samples with a wide range depending on bat species, suggesting past exposure to a lyssavirus. Notably, EBLV-1 was detected in brain tissue samples from two Eptesicus serotinus specimens collected in 2016 near Bertrix and 2017 near Étalle, confirming for the first time the presence of EBLV-1 in Belgium and raising awareness of the potential risks associated with this species of bats as reservoirs of the virus.

Sex, season, age and status influence urinary steroid hormone profiles in an extremely polygynous neotropical bat.

Several polygynous mammals exhibit reproductive skew in which only a few males reproduce. Successful males need strength, stamina and fighting ability to exclude competitors. Consequently, during the mating season their androgens and glucocorticoids are expected to increase to support spermatogenesis and aggressive behavior. But, during the nonmating season these hormones should decline to minimize deleterious effects, such as reduced immune function. Bats that exhibit harem polygyny in which males aggressively defend large groups of females year-round are ideal for assessing hormonal and other consequences of extreme polygyny. Here we use DNA methylation to estimate age and gas chromatography, tandem mass spectrometry to profile steroid metabolites in urine of wild greater spear-nosed bats, Phyllostomus hastatus, across seasons. We find that condition, measured by relative weight, is lower during the mating season for both sexes, although it remains high in harem males during the mating season. Average age of females is greater than males, and females exhibit substantial seasonal differences in androgens, estrogens and glucocorticoids with higher levels of all hormones during the mating season. Males, however, show little seasonal differences but substantial age-associated increases in most steroid metabolites. Harem males have larger, persistently scrotal testes and are older than bachelor males. While cortisone generally declines with age, harem males maintain higher amounts of biologically active cortisol than bachelor males all year and cortisol levels increase more quickly in response to restraint in males than in females. Taken together, these results suggest that attaining reproductive dominance requires hormone levels that reduce lifespan.