Presence Of Bats Research Articles

Soundwaves in the North Atlantic: Detecting the offshore bats of Sable Island

As Sable Island National Park Reserve approaches a decade of protection under Parks Canada, new data on the island’s biodiversity is useful for informing management. An ultrasonic autonomous recording unit was deployed for 15 months over two years (October 5, 2015-January 8, 2017) to quantitatively characterize the presence of bats on Sable Island. A total of 1721 echolocation passes were identified across the 32 nights that bats were detected on the island (6.9% of total recording nights). Of the nights that bats were detected, Lasionycteris noctivagans (Silver-haired Bat) was present on 65% of nights, Myotis species were present on 53% of nights, Lasiurus borealis (Eastern Red Bat) was present on 25% of nights, and Lasiurus cinereus (Hoary Bat) was present on 6.25% of nights. All recordings were captured between late-September and early-December. Evidence of bat species on Sable Island, whether deliberately stopping during migration or brought there by external factors such as weather, highlights that the island may be more important for bats than previously thought. Keywords: bats, bioacoustics, migration, monitoring, Sable Island

Helminth Fauna of Bats of the Rostov Region: Review. 2. Trematoda

Introduction. The class of Trematoda includes two subclasses — Aspidogastrea and Digenea. Representatives of the former do not parasitize in bats. The definitive hosts for digenetic trematodes (Digenea) are vertebrates, including bats, in which the sexual generation (maritae) parasitizes. Gastropods or bivalves are the intermediate hosts. Supplementary hosts for the trematodes of bats are larvae and imagos of flying insects. Since in most cases the development of parthenites and cercariae of trematodes is related to water environment, the supplementary hosts are the groups of insects whose larvae live in the water. The list of bat species living in the Rostov region has been compiled in the previous research. In the present article the authors investigate the trematode fauna parasitizing in bats of the region under study. The aim of this review is to analyse the current state of knowledge on the species composition of the helminth parasitizing in chiropterans of the Rostov region.Materials and Methods. The research materials have been obtained from the libraries and open access resources: PubMed (pubmed.ncbi.nlm.nih.gov), CyberLeninka (cyberleninka.ru), Google Scholar (scholar.google.com), BHL (www.biodiversitylibrary.org), JSTOR (www.jstor.org). Some data has been provided by the colleagues.Results. 42 trematode species from 10 genera, 5 families and 1 order can parasitize in 15 bat species living in the Rostov region. The Lecithodendriidae family (24 species) and the genus Paralecithodendrium (9 species) are represented by a large number of species. Of the listed trematodes, 33 species used to be recorded on the territory of Russia.Discussion and Conclusion. The results of the conducted systematic review have revealed that the largest number of trematode species parasitizes in two bat species living in the Rostov region: the common noctule (27 species) and the serotine bat (24 species). The smallest number of species (4 per each) is found in the giant noctule and the soprano pipistrelle bat. Two species (Plagiorchis elegans and Plagiorchis vespertilionis) have been found in the companion cats and dogs includingly, wheras a case of the latter parazitising in humans has also been recorded. The presence of bats in the urban environment enables the full life cycle of these trematodes. There exists possibility of the companion animals and people to get infected through incidental ingestion of the infested insects.

Dangerous neighbours: Birds and bird-eating bats sharing tree cavities.

Mounting evidence indicates the non-consumptive effects of predators significantly impact prey physiology, ecology and behaviour. Passerine birds experience adverse effects on nesting and reproductive success when in proximity to predators. Fear of predators is context-dependent and influenced by hunting habitats and foraging strategies. While some bat species prey on birds, the greater noctule (Nyctalus lasiopterus) stands out by specialising in avian prey, especially during peak bird migration. N. lasiopterus is thought to seize avian prey in flight, but direct evidence is lacking. If birds were taken from nests, they would likely avoid nesting near these bats. However, no observations support this view. This study documents the successful reproduction of Eurasian blue tits (Cyanistes caeruleus) nesting alongside a colony of approximately 25 greater noctules. This bird species is a prey species for greater noctules in Italy. Over about 1 month (April-May 2023), we observed parent birds provisioning food to chicks, with at least two chicks alive and fed outside the tree cavity by the end of the period. While acknowledging the limitations of a single observation, we propose that this previously unknown behaviour indirectly supports the idea that greater noctules only capture avian prey in flight, not within confined spaces. This observation challenges the perception that these bats pose a threat when sharing roosting spaces in trees, as evidenced in our observed case. We hope this novel observation inspires future research on variations in bird nesting behaviour and reproductive success in the presence of bird-eating bats, as well as an assessment of the long-term impact on population dynamics and reproductive success of nesting birds sharing such roosting spaces.

Effects of Habitat and Fruit Scent on the Interactions between Short-tailed Fruit Bats and Piper Plants.

Piper is a mega-diverse genus of pioneer plants that contributes to the maintenance and regeneration of tropical forests. In the Neotropics, Carollia bats use olfaction to forage for Piper fruit and are a main disperser of Piper seeds via consumption and subsequent defecation during flight. In return, Piper fruits provide essential nutrients for Carollia year-round. There is evidence that the types and diversity of Piper frugivores are influenced by the primary habitat type of different Piper species (forest and gap), with forest Piper depending more on bats for seed dispersal; however, this pattern has not been tested broadly. We aimed to characterize and compare the interactions between Carollia and Piper across forested and gap habitats, and further investigate whether differences in fruit traits relevant to bat foraging (i.e., scent) could underlie differences in Carollia-Piper interactions. We collected nightly acoustic ultrasonic recordings and 24 h camera trap data in La Selva, Costa Rica across 12 species of Piper (six forest, six gap) and integrated this information with data on Carollia diet and Piper fruit scent. Merging biomonitoring modalities allowed us to characterize ecological interactions in a hierarchical manner: from general activity and presence of bats, to visitations and inspections of plants, to acquisition and consumption of fruits. We found significant differences in Carollia-Piper interactions between forested and gap habitats; however, the type of biomonitoring modality (camera trap, acoustics, diet) influenced our ability to detect these differences. Forest Piper were exclusively visited by bats, whereas gap Piper had a more diverse suite of frugivores; the annual diet of Carollia, however, is dominated by gap Piper since these plants produce fruit year-round. We found evidence that fruit scent composition significantly differs between forest and gap Piper, which highlights the possibility that bats could be using chemical cues to differentially forage for gap vs. forest Piper. By integrating studies of Piper fruit scent, plant visitation patterns, and Carollia diet composition, we paint a clearer picture of the ecological interactions between Piper and Carollia, and plant-animal mutualisms more generally.

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.

Bats (Chiroptera) of the Ujście Warty National Park and the surrounding area

Bat research was carried out in 2012-2013 in the Ujście Warty National Park and in adjacent areas. Bats were caught in chiropterological nets, searched for in winter and summer roosts. Detector listening was carried out and the owls' diet was analyzed for the presence of bats among their prey. In the national park area, 11 species of bats were detected, and together with the Natura 2000 area "Ujście Warty" and the neighbouring areas, a total of 15 species were detected: the Daubenton's bat Myotis daubentonii, Natterer's bat Myotis nattereri, Brandt's bat Myotis brandtii, noctule bat Nyctalus noctula, serotine bat Eptesicus serotinus, common pipistrelle bat Pipistrellus pipistrellus, soprano pipistrelle bat Pipistrellus pygmaeus, Nathusius' pipistrelle bat Pipistrellus nathusii, brown long-eared bat Plecotus auritus, gray long-eared bat Plecotus austriacus, western barbastelle bat Barbastella barbastellus, greater mouse-eared bat Myotis myotis, Bechstein's bat Myotis bechsteinii, pond bat Myotis dasycneme and the parti-coloured bat Vespertilio murinus. The bat fauna of this area is relatively rich compared to other protected areas and presented results constitute an important supplement to the knowledge about the vertebrate fauna of the national park and its vicinity.

Far-reaching displacement effects of artificial light at night in a North American bat community

Artificial light at night (ALAN) is a global pollutant that disrupts circadian rhythmicity and a broad range of physiological processes and behaviors in animals. However, ALAN sensitivity can vary greatly even among closely related species and urgently needs study for much of the world’s nocturnal wildlife, including bats. While an increasing number of bat species have recently been assessed for light tolerance, the spatial extent of ALAN’s influence on bats has received little attention. This information need is a barrier to the protection of bats from ALAN in land-use planning and policy, and the development of best practices that effectively buffer bat habitat from light trespass. To help address this information gap for North America, we experimentally tested the distances up to which ALAN affects presence and activity of light-averse little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus), and the composition of a foraging bat assemblage in Connecticut, USA. We used three residential-scale, white, LED floodlights to expose bat foraging habitat to ALAN and compared acoustic activity of bats at distances of 0, 25, 50, and 75 m from the lights between nights when the lights were on versus off. Little brown bats were present on significantly fewer light than dark nights at every distance. Lighting significantly reduced little brown bat activity overall and at the farthest location from the lights (75 m), where it was only 43% of dark-night activity despite < 1 lx of illuminance. Presence of big brown bats was not significantly affected at any distance. Big brown bat activity on light nights averaged 48–75% of dark-night activity at each distance but was significantly lower only at 0 m. As expected, lighting had no effect on eastern red (Lasiurus borealis) or hoary bat (L. cinereus) presence or activity. Community composition on dark and light nights had an average dissimilarity of 38% and significantly differed at 0 m and 25 m. We conclude the type of ALAN we studied has a disturbance radius of at least 75 m for the little brown bat and up to 25 m for the big brown bat, with a resulting influence on community composition for up to 50 m. Cumulative habitat loss for the imperiled little brown bat caused by ALAN could therefore be substantial. We urge planners and natural resources regulators to consider these footprints when evaluating indirect impacts to bat habitat from current and future sources of ALAN across these species’ ranges.

Foraging and mating behaviors of Hypsignathus monstrosus at the bat-human interface in a central African rainforest.

Studying wildlife space use in human-modified environments contributes to characterize wildlife-human interactions to assess potential risks of zoonotic-pathogens transmission, and to pinpoint conservation issues. In central African rainforests with human dwelling and activities, we conducted a telemetry study on a group of males of Hypsignathus monstrosus, a lek-mating fruit bat identified as a potential maintenance host for Ebola virus. During a lekking season in 2020, we investigated the foraging-habitat selection and the individual nighttime space use during both mating and foraging activities close to villages and their surrounding agricultural landscape. At night, marked individuals strongly selected agricultural lands and more generally areas near watercourses to forage, where they spent more time compared to forest ones. Furthermore, the probability and duration of the presence of bats in the lek during nighttime decreased with the distance to their roost site but remained relatively high within a 10 km radius. Individuals adjusted foraging behaviors according to mating activity by reducing both the overall time spent in foraging areas and the number of forest areas used to forage when they spent more time in the lek. Finally, the probability of a bat revisiting a foraging area in the following 48 hours increased with the previous time spent in that foraging area. These behaviors occurring close to or in human-modified habitats can trigger direct and indirect bat-human contacts, which could thus facilitate pathogen transmission such as Ebola virus.

Bats as ecosystem engineers in iron ore caves in the Carajás National Forest, Brazilian Amazonia.

Ecosystem engineers are organisms able to modify their environment by changing the distribution of materials and energy, with effects on biotic and abiotic ecosystem components. Several ecosystem engineers are known, but for most of them the mechanisms behind their influence are poorly known. We detail the role of bats as ecosystem engineers in iron ore caves in the Carajás National Forest, Brazilian Amazonia, an area with > 1,500 caves, some holding ~150,000 bats. We analyzed the chemical composition of guano deposits in bat caves, radiocarbon-dated those deposits, and elucidated the chemical mechanisms involved and the role the bat guano has on modifying those caves. The insect-composed guano was rich in organic matter, with high concentrations of carbon, nitrogen, phosphorus pentoxide and ferric oxide, plus potassium oxide, calcium and sulfur trioxide. Radiocarbon dating indicated guano deposits between 22,000 and 1,800 years old. The guano pH was mainly acid (from 2.1 to 5.6). Percolating waters in those bat caves were also acid (pH reaching 1.5), with the presence of phosphate, iron, calcium, nitrate and sulfate. Acid solutions due to guano decomposition and possible microbial activity produced various forms of corrosion on the caves´ floor and walls, resulting in their enlargement. Bat caves or caves with evidence of inactive bat colonies had, on average, lengths six times larger, areas five times larger, and volumes five times bigger than the regional average, plus more abundant, diversified and bigger speleothems when compared with other caves. In an example of bioengineering, the long-term presence of bats (> 22,000 years) and the guano deposits they produce, mediated by biological and chemical interactions over millennia, resulted in very unique ecological, evolutionary and geomorphological processes, whose working are just beginning to be better understood by science. However, the current expansion of mineral extraction activities coupled with the loosening of licensing and cave protection rules is a real conservation threat to the bat caves in Carajás. The destruction of those caves would represent an unacceptable loss of both speleological and biological heritage and we urge that, whenever they occur, bat caves and their colonies must be fully protected and left off-limits of mineral extraction.

Out of thin air: surveying tropical bat roosts through air sampling of eDNA.

Understanding roosting behaviour is essential to bat conservation and biomonitoring, often providing the most accurate methods of assessing bat population size and health. However, roosts can be challenging to survey, e.g., physically impossible to access or presenting risks for researchers. Disturbance during monitoring can also disrupt natural bat behaviour and present material risks to the population such as disrupting hibernation cycles. One solution to this is the use of non-invasive monitoring approaches. Environmental (e)DNA has proven especially effective at detecting rare and elusive species particularly in hard-to-reach locations. It has recently been demonstrated that eDNA from vertebrates is carried in air. When collected in semi-confined spaces, this airborne eDNA can provide remarkably accurate profiles of biodiversity, even in complex tropical communities. In this study, we deploy novel airborne eDNA collection for the first time in a natural setting and use this approach to survey difficult to access potential roosts in the neotropics. Using airborne eDNA, we confirmed the presence of bats in nine out of 12 roosts. The identified species matched previous records of roost use obtained from photographic and live capture methods, thus demonstrating the utility of this approach. We also detected the presence of the white-winged vampire bat (Diaemus youngi) which had never been confirmed in the area but was long suspected based on range maps. In addition to the bats, we detected several non-bat vertebrates, including the big-eared climbing rat (Ototylomys phyllotis), which has previously been observed in and around bat roosts in our study area. We also detected eDNA from other local species known to be in the vicinity. Using airborne eDNA to detect new roosts and monitor known populations, particularly when species turnover is rapid, could maximize efficiency for surveyors while minimizing disturbance to the animals. This study presents the first applied use of airborne eDNA collection for ecological analysis moving beyond proof of concept to demonstrate a clear utility for this technology in the wild.

DIVERSIDAD DE MURCIÉLAGOS FRUGÍVOROS Y SEMILLAS CONSUMIDAS EN BORDES DE BOSQUE MESÓFILO DE MONTAÑA, VERACRUZ, MÉXICO

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;The change in the coverage of the Cloud Forest (CF) generates edges and fragments of original vegetation that can affect the bat community and the diversity of dispersed seeds. &lt;strong&gt;Objective:&lt;/strong&gt; The objective was to describe the diversity of frugivorous bats and the seeds that they consume in different types of edges in the BMM, in Huatusco, Veracruz, Mexico. &lt;strong&gt;Methodology:&lt;/strong&gt; Sampling with nets every 28 days for the capture and identification of bats was carried out in seven months, their feces were collected and the contained seeds were germinated to estimate a germination rate and for their taxonomic identification. The bat community and the seeds consumed were evaluated with true diversity indicators; the disperser importance index (IID) was estimated with the percentage of seeds dispersed by bat species. &lt;strong&gt;Results:&lt;/strong&gt; 503 individuals of 14 species of frugivorous bats were captured in the four borders of the BMM, but the highest presence (13 spp.) and abundance (60%) of frugivorous-polynectarivorous bats was recorded in the border of the BMM with Grassland, where &lt;em&gt;Anoura geoffroyi&lt;/em&gt;, &lt;em&gt;Sturnira ludovici&lt;/em&gt; and &lt;em&gt;S. lilium&lt;/em&gt; had the highest abundance, but only three species of bats are dispersal agents. A total of 69 bat droppings with 1380 seeds belonging to four botanical families were collected, with Rubiaceae and Solanaceae having the highest frequency of seeds consumed, and Piperaceae and Solanaceae with the greatest diversity of seeds. The highest quantity (65%) and diversity of seeds (10 spp.) were recorded on the BMM-Grassland border, with &lt;em&gt;Borreria laevis&lt;/em&gt; seeds being the most consumed (30%). &lt;strong&gt;Implications: &lt;/strong&gt;This study allows us to understand the ecological importance of biotic interactions between bats and plants in BMM borders. &lt;strong&gt;Conclusions:&lt;/strong&gt; The edges of heterogeneous BMM conglomerate greater diversity and abundance of bats.&lt;/p&gt;

The presence of wind turbines repels bats in boreal forests

Impacts of wind power on bats are usually evidenced by the recorded fatalities, while other impacts are not well understood or considered during project planning. However, wind turbines may affect use of the surrounding habitats by bats. Little is known about such impact, especially in the European boreal biogeographical region. We studied the consequences of operating wind turbines on the presence and activity of bats in forests. We simultaneously monitored bat acoustic activity at 84 sampling sites placed at 200 m intervals from 0 to 1.000 m (2 recorders per distance class), over four months and at seven Finnish wind farms located in forested habitats. Our results show higher presence and activity at 600 m and further from turbines for Eptesicus nilssonii, and higher presence at 800 m and further for Myotis spp. We also saw an increase in bat activity during midsummer, which may be due to increased use of forest canopy cover during the short nights at this time. These results indicate a potential loss in habitat quality around wind turbines, e.g., a greater number of open areas in forests unfavourable to certain bat species. This lower activity and presence could also be an indication for active avoidance of the wind turbines from the bats. Furthermore, these results are the first of their kind for Eptesicus nilssonii, and for the European boreal biogeographical region. They show undeniable impacts of wind power on bats in Finland, and enforce the requirement for better consideration of bats during the development of such projects in Finland. Similarly, these results show impacts of operating turbines on habitat use by bats, impacts that now must be considered in Europe. We also call for investigation on the causative mechanisms of the observed effect, to better facilitate mitigation.

Sero-epidemiology of Marburg virus amongst respondents in Sobi Area, Ilorin, Kwara State, Nigeria

Marburg virus disease is a hemorrhagic fever of public health importance. There is sparse information on its prevalence in Nigeria. This study was aimed at determining the serological epidemiology and molecular confirmation of MV amongst inhabitants of Sobi in Ilorin, Nigeria in order to forestall a potential outbreak of MVD. Serological evaluation of collected blood samples from consenting participants was carried out using MELSIN ELISA kit for antibody detection. Structured questionnaire was used to collect risk factor data. This study revealed the serological presence of Marburg virus IgG (26.5%) and IgM (19.0%) in this locality(P&lt;0.05). MV IgG and IgM prevalence by evaluated risk factors were 12 (23.5%) and 6 (16.7%), 11 (21.6%) and 9 (25.0%), and 27 (50.9%) and 13 (34.2%) for presence of bats in vicinity, respondent’s visitation to park/zoo and presence of trees in residential area respectively at varying statistical correlations. Consumption of sick animals, contact with dead animals and involvement in preparation of dead body for burial showed an IgG/IgM positivity of 4 (7.7%)/2 (5.4%), 3 (5.8%)/4 (10.8%) and 11 (21.2%)/4 (10.8%) respectively. Higher frequency of contact or closer proximity to known risk factors showed higher prevalence and bats within vicinity revealed to be more amongst respondent with tree in residential area than those closer to Sobi hill. Reduction of bat to human contact and hygienic practices in occupation/research involving animals should be encouraged.

A One Health approach to investigate bats as a potential source of zoonotic mycoses in selected areas of Mpumalanga province, the Republic of South Africa

A One Health approach pilot study was carried out in selected villages within the Mnisi Traditional Authority’s area, Manyeleti Game Reserve, and Hans Hoheisen Wildlife Research Station in Mpumalanga Province, the Republic of South Africa from July to December 2018. The study’s main objectives were to identify positive and negative human-bat-environment interactions and microbiological screening of bats’ faecal samples for zoonotic fungi. Thirty-three purposively selected participants were asked to complete a structured questionnaire with multiple-choice and open-ended questions, and a total of 55 faecal samples were collected, 25 from identified bat roosting sites and 30 from captured bats. Ninety seven percent of respondents were aware of the presence or absence of bats in their immediate surroundings. However, the majority of them (87.9%) were uneasy about the presence of bats in their buildings, and nearly half (48.5%) were unsure whether bats play a positive or negative role in the environment. Some respondents (15.2%) stated that bats play beneficial roles in the environment, such as pollinating plants, spreading seeds of indigenous plants, catching harmful insects, and so on. More than half of the respondents (66.7%) stated that bats can be a nuisance; 18.2% of those polled reported contracting fungal diseases as a result of cleaning bat droppings without adequate protection. The analysis of faecal samples revealed that bats can harbour pathogenic fungi such as Aspergillus fumigatus, and A.flavus. We concluded that bats can harbour fungal pathogens that cause human diseases. Further research should be conducted to compile a complete list of fungi pathogens in bats in the study area.

Zaire ebolavirus surveillance near the Bikoro region of the Democratic Republic of the Congo during the 2018 outbreak reveals presence of seropositive bats.

On the 8th of May, 2018, an outbreak of Ebola virus disease (EVD) was declared, originating in the Bikoro region of the Democratic Republic of the Congo (DRC) near the border with neighboring Republic of the Congo (ROC). Frequent trade and migration occur between DRC and ROC-based communities residing along the Congo River. In June 2018, a field team was deployed to determine whether Zaire ebolavirus (Ebola virus (EBOV)) was contemporaneously circulating in local bats at the human-animal interface in ROC near the Bikoro EVD outbreak. Samples were collected from bats in the Cuvette and Likouala departments, ROC, bordering the Équateur Province in DRC where the Bikoro EVD outbreak was first detected. EBOV genomic material was not detected in bat-derived samples by targeted quantitative reverse transcription-polymerase chain reaction or by family-level consensus polymerase chain reaction; however, serological data suggests recent exposure to EBOV in bats in the region. We collected serum from 144 bats in the Cuvette department with 6.9% seropositivity against the EBOV glycoprotein and 14.3% seropositivity for serum collected from 27 fruit bats and one Molossinae in the Likouala department. We conclude that proactive investment in longitudinal sampling for filoviruses at the human-animal interface, coupled with ecological investigations are needed to identify EBOV wildlife reservoirs.

Distribution and Roost Site Selection of Eastern Small-Footed Bats (Myotis leibii) in Mountains of West-Central Arkansas

Myotis leibii (Eastern Small-footed Bat) is a rare species in eastern North America that is threatened by habitat loss and white-nose syndrome. Although rare, this species cannot be adequately evaluated for listing on the Endangered Species Act because of data deficiencies, including about its distribution and roost habitat. Our objectives were to document the distribution of Eastern Small-footed Bats and determine landscape and local characteristics that influence their probability of presence in the mountains of west-central Arkansas. Using acoustic monitoring, visual searches of rock formations, and mist-netting, we found that presence of Eastern Small-footed Bats was more likely in regions with talus slopes and nearby forest cover. These features may benefit the species by providing abundant options for roost switching, unique thermal properties, and short distances to foraging habitat.

Do bats use scent cues from guano and urine to find roosts?

Selection of habitat is a key determinant of reproductive success, and the process of finding and choosing these sites is often influenced by the presence of conspecifics. Many bats frequently switch roosts, and some bats repeatedly find new roosts. To find roosts with conspecifics or group members, bats can use social cues. However, most research on how bats use social cues for roost-finding has focused on acoustic cues. Here, we review and discuss the evidence for bat roost selection using scent cues from guano and urine stains, which are present at most bat roosts. We outline reasons why bats might, or might not, use scent in roost detection and selection, and we review evidence on the possible use of guano and urine in roost-finding from eight studies with 12 bat species (across four families). Overall, the sparse evidence that exists indicates that scent cues from guano and urine are not a strong and consistent lure in the species and situations that were tested. Most studies had unclear results or found no effect. Two of the eight studies found weak experimental evidence for bats using guano or urine to select a roosting site. Even if guano and urine can indicate the presence of bats at a roost, it is possible that the resulting olfactory cues do not contain sufficient social information to be used in roost selection, in contrast to olfactory cues from scent marking. Studies of how bats use sensory cues beyond sound could contribute to a better understanding of bat social behavior and roosting ecology.

Identification of fresh and burnt bat guano and pigeon droppings in Eastern Mediterranean karstic cave sites based on micromorphological and chemical characteristics

Karstic caves in the Eastern Mediterranean region hold significant archaeological importance as they served as an important dwelling place for prehistoric hominins. Yet, such caves were used at the same time as a habitat for birds and bats. As a result, bat guano and bird droppings are not only a major source of cave deposits, but also trigger significant chemical alterations (diagenesis) due to their decomposition that can greatly affect the preservation of archaeological materials as reported from many Palaeolithic cave sites. While the diagenetic processes associated with bat guano degradation are quite well understood, the identification of partially-preserved or burnt guano residues in archaeological cave sites has not received much attention. Here we present a micromorphological, chemical and mineralogical study of modern guano of insectivorous bats, frugivorous bats and pigeons, collected from karstic caves in Israel. Each of these guano types was studied in fresh, charred and ashed forms. Based on the patterns obtained we present guidelines that allow identification of partially-degraded and burnt bat and bird guano remains. These include (1) high phosphorous and calcium associated with high quantities of chitin fragments in insectivorous bat guano; (2) low phosphorous and calcium associated with high quantities of seed coats, fibrous organic matter and red oval organic particles in frugivorous bat and pigeon guano. We found that faecal spherulites are present in bat guano and absent in pigeon droppings. Blackening and rounding of the edges of organic components characterise guano upon charring, while ashed guano is characterised by a micritic calcite groundmass in the case of fruit bat and pigeon guano without any pseudomorphs after calcium oxalate, unlike wood ash. We further show that ashed insectivorous bat guano is characterised by a micritic groundmass that includes phosphatic particles and potassium sulphate. These data indicate that while the combustion of guano presents similarities to other organic-based burnt deposits found in archaeological sites, a careful micromorphological study, aided by certain elemental and mineralogical signatures, can reveal whether or not burnt deposits originate from guano. Last, we studied the micromorphology of in situ degraded frugivorous and insectivorous bat guano in caves, observing that a bedded and laminated structure characterises fresh deposits while, as degradation progresses the proportion of authigenic minerals, appearing as nodules and veins, increases, disrupting the laminated structure. Importantly, chitin fragments in insectivorous bat guano and seed coats and some organic fibers in frugivorous bat guano preserve within degraded bat guano deposits and can serve as indicators for the presence and feeding habits of bats. Applying the guidelines given here to archaeological studies at prehistoric cave sites may produce new insights regarding human behavior, human–bat interactions, as well as for the formation processes at these sites.

Spatial epidemiology of Leptospira sp. exposure in bovines from Veracruz, México.

Bovine leptospirosis is a bacterial disease that affects cattle herds, causing economic losses due to reproductive problems which require expensive treatments. The main source of transmission for cattle is still uncertain, but rodents and bats can play an important role in the transmission cycle by being maintenance hosts for the pathogenic species of the bacterium and spreading it through urine. In this study, we characterize possible risk areas for bovine leptospirosis exposure in the state of Veracruz, Mexico, based on the geographical distribution of flying (bats) and terrestrial (rodents and opossums) wild hosts of Leptospira sp. reported in Mexico, in addition to climate, geography, soil characteristics, land use and human activities (environmental variables). We used a generalized linear regression model to understand the association between the frequency of anti-Leptospira sp. antibodies (a proxy of exposure) in cattle herds exposed to Leptospira, the favourability of wild hosts of Leptospira as well as the environmental variables. The parameterized model explained 12.3% of the variance. The frequency of anti-Leptospira sp. antibodies exposure in cattle herds was associated with elevation, geographic longitude, pH of the soil surface and environmental favourability for the presence of rodents, opossums and bats. The variation in exposure was mainly explained by a longitudinal gradient (6.4% of the variance) and the favourability-based indices for wild hosts (9.6% of the variance). Describing the possible risks for exposure to Leptospira in an important and neglected livestock geographical region, we provide valuable information for the selection of areas for diagnosis and prevention of this relevant disease.

Monitoring and Modeling Tree Bat (Genera: Lasiurus, Lasionycteris) Occurrence Using Acoustics on Structures off the Mid-Atlantic Coast-Implications for Offshore Wind Development.

Simple Summary“Tree bats” are North American bats that day-roost in trees year-round and undertake seasonal migration in lieu of hibernation. These bats have been shown to be highly susceptible to collisions with wind energy turbines and are known to fly offshore during migration. Therefore, as offshore wind energy expands off the eastern U.S. coast, there is some concern about potential impacts. We monitored bats in coastal Virginia, USA, using acoustic monitors—devices that collect the unique echolocation call signatures of bat species. We found that nightly tree bat visitation offshore or on barrier islands was associated with wind speed, temperature, visibility, and seasonality. Using statistical modeling, we developed a predictive tool to assess occurrence probabilities at varying levels of wind speed, temperature, and seasonality. Probability of occurrence and therefore assumed risk to collision is highest on high temperature and visibility nights, low wind speed nights, and during the spring and fall seasons. We suggest a similar modeling regime could be used to predict the occurrence of bats at offshore wind sites to inform potential mitigation efforts.In eastern North America, “tree bats” (Genera: Lasiurus and Lasionycteris) are highly susceptible to collisions with wind energy turbines and are known to fly offshore during migration. This raises concern about ongoing expansion of offshore wind-energy development off the Atlantic Coast. Season, atmospheric conditions, and site-level characteristics such as local habitat (e.g., forest coverage) have been shown to influence wind turbine collision rates by bats onshore, and therefore may be related to risk offshore. Therefore, to assess the factors affecting coastal presence of bats, we continuously gathered tree bat occurrence data using stationary acoustic recorders on five structures (four lighthouses on barrier islands and one light tower offshore) off the coast of Virginia, USA, across all seasons, 2012–2019. We used generalized additive models to describe tree bat occurrence on a nightly basis. We found that sites either indicated maternity or migratory seasonal occurrence patterns associated with local roosting resources, i.e., presence of trees. Across all sites, nightly occurrence was negatively related to wind speed and positively related to temperature and visibility. Using predictive performance metrics, we concluded that our model was highly predictive for the Virginia coast. Our findings were consistent with other studies—tree bat occurrence probability and presumed mortality risk to offshore wind-energy collisions is highest on low wind speed nights, high temperature and visibility nights, and during spring and fall. The high predictive model performance we observed provides a basis for which managers, using a similar monitoring and modeling regime, could develop an effective curtailment-based mitigation strategy.