Heavy metals are persistent, bioaccumulating pollutants, and assessing their exposure in biota requires indicators that capture spatial variability. This study evaluated fresh bat guano from different sites as a non-invasive matrix for characterising multi-element metal profiles and testing spatial differences among locations within species. Atomic Absorption Spectroscopy (AAS) technique was used to determine the concentrations of Mn, Fe, Ni, Cu, Zn, Cd, Hg, and Pb. Data were analysed after log10 transformation. Descriptive statistics and the Metal Pollution Index (MPI) were calculated, within-species location effects were tested using Welch ANOVA, and profile structure was further explored using hierarchical clustering, Spearman correlations and principal component analysis (PCA). MPI revealed marked spatial heterogeneity, ranging from 0.995 to 1.47, corresponding to an approximately threefold difference between the least and most affected sites. In the lesser horseshoe bat species, location significantly affected Mn, Fe, Ni, Cd, Hg, and Pb whereas in the greater mouse-eared bat the effect persisted for all analysed metals. The strongest positive correlations were Cu-Zn (ρ = 0.958) and Mn-Ni (ρ = 0.786). Together with MPI, fingerprint analysis and correlation structure, PCA supported the interpretation that fresh guano carries a structured spatial signal of metal mixtures and may therefore be useful in non-invasive environmental monitoring.

Interactions between two protected species: Rhinolophus ferrumequinum impacting the recovery of Rhinolophus hipposideros populations in Britain

We present a genome assembly from an individual female Rhinolophus hipposideros (Lesser Horseshoe Bat; Chordata; Mammalia; Chiroptera; Rhinolophidae). The assembly contains two haplotypes with total lengths of 2 171.31 megabases and 2 240.90 megabases. Most of haplotype 1 (96.52%) is scaffolded into 29 chromosomal pseudomolecules, including the X sex chromosome. Most of haplotype 2 (93.46%) is scaffolded into 29 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled, with a length of 16.85 kilobases. Gene annotation of this assembly on Ensembl identified 18 700 protein-coding genes. This assembly was generated as part of the Darwin Tree of Life project, which produces reference genomes for eukaryotic species found in Britain and Ireland.

Following the report of neonate mortality in the Kaf El Ghar cave, Taza province, Morocco, we conducted two diurnal visits over two years (2023 and 2024) to assess diversity and breeding of bats in the cave and surrounding habitat. In the Garden house (foraging habitat), we used an automated bat detector SM4, positioned at 4 m of height from midnight to sunset. The following day, we made a diurnal visit to Kaf El Ghar cave, combining echolocation calls detection, hand netting of nearby bats, and counts of deceased neonates and other bats found on the ground. In the foraging area, we identified six bat species: Pipistrellus pipistrellus (517 acoustic detection), Miniopterus schreibersii (12), Eptesicus isabellinus (4), Rhinolophus hipposideros (4), and Myotis punicus (1). Inside Kaf El Ghar cave, we recorded M. schreibersii (720 individuals in the first year, 640 in the second) and M. punicus (500 and 460, respectively), alongside smaller numbers of E. isabellinus (5 and 7 detections), and Rhinolophus euryale (3 detections). Both M. schreibersii and M. punicus occupied the ceiling of the maternity room, bearing their young. In total, 286 cadavers (127 in the first year, 159 in the second year) were counted from the ground of the maternity gallery, consisting primarily of juveniles of M. schreibersii and M. punicus, with a single adult female R. euryale. This study highlights the critical role of Kaf El Ghar cave as a maternity site and underscores significant juvenile mortality during the breeding period, emphasizing the need for focused conservation efforts.

ABSTRACTIslands provide unique opportunities to study historical biogeography, acting as both cradles of endemism and active corridors for species dispersal. The Sicilian Channel, which separates Sicily from the Maghreb, exemplifies this complexity. We investigated the colonisation history of the lesser horseshoe bat (Rhinolophus hipposideros) on Pantelleria Island (southern Italy) to assess whether its population derives from Europe or North Africa. Because R. hipposideros has limited dispersal ability and is largely sedentary, its occurrence on Pantelleria raises questions about past connectivity across the Channel. We analysed mitochondrial markers (COI, cyt‐b, 12S) from Pantelleria, Malta, Algeria, and across the species' range. Phylogenetic and haplotype network analyses place Pantelleria and Malta in a well‐supported clade sister to North African lineages and distinct from European populations. Time‐calibrated analyses based on cyt‐b suggest that the Pantelleria–Malta group diverged from North African conspecifics around 200,000 years ago (MIS 7.2). A palaeogeographical reconstruction for this interval indicates lowered sea level reduced the marine gap between Pantelleria and Tunisia to about 68 km, consistent with over‐sea colonisation from North Africa. The short available sequences for conspecific European bats suggest considering these inferences as provisional. Within these limitations, our results are most consistent with a Maghrebian origin for Pantelleria's R. hipposideros, while alternative routes (including European sources) cannot be excluded. Broader genomic sampling, especially from Sicily and Morocco, will be required to resolve colonisation direction and fully establish the population's biogeographic history. More generally, our findings reinforce the view of the Sicilian Channel as an asymmetrically permeable biogeographic corridor that can facilitate faunal exchange across the central Mediterranean.

ABSTRACT In 2024 and 2025, during the annual winter bat monitoring organized in Poland, the Lesser Horseshoe Bat was found hibernating in underground sites in north-western Poland. This is the first finding of this species outside the northern limit of its occurrence on the European continent. It is most likely that Rhinolophus hypossideros recorded in the same wintering site year after year is one and the same specimen, which remained in the new site throughout the year until the following winter. Following the observations, recording of the Lesser Horseshoe Bat’s presence in the new area using ultrasonic detectors began in 2025.

ABSTRACT Aim Species Distribution Models (SDMs) are widely used to map species distribution and predict future responses to climate change. While the risk of selecting biologically non‐relevant predictors has been raised, numerous studies continue to fully rely on statistical approaches to automatically select predictors solely focusing on climate variables. Yet, relying only on climate can have important implications for the reliability of the estimated relationships and predictions. Here, we illustrate the implications of ignoring species biology when modelling species distribution. Location West Palearctic. Taxon Boreus westwoodi Hagen, Crucianella maritima L., Rhinolophus hipposideros (Bechstein). Methods We compared a naive, statistically‐informed model selection approach (relying on the full set of 19 bioclimatic variables) with expert‐informed models where we included only variables specifically linked to a species' biology. We tested our approach on three case study species: B. westwoodi , a Palaearctic insect related to snow cover; C. maritima , a Mediterranean coastal dune plant; and R. hipposideros , a forest bat occurring across Europe and the Middle East. Results The two variable selection approaches identified different sets of variables as relevant in all case studies; although the models yielded similar predictive performance. This resulted in consistent differences between predictions under current and novel conditions, along with differences in interpretability of response curves, driven by variables with no clear ecological significance. Main Conclusions We emphasise the importance of a thoughtful selection of predictors based on species biology over naive bioclimatic models. We argue that taxonomy, general adaptations and biome characteristics can guide variable selection when species‐specific information is lacking and that a rational exclusion of non‐relevant variables is often feasible even with limited knowledge. Strengthening the ecological foundation of SDMs will enhance their utility in climate change impact assessments and support biodiversity conservation efforts.

Abstract A detailed knowledge of habitat use by bats is crucial for their effective conservation. Several studies have underlined the importance of forests for bats. This also holds for the European hot spot of bat diversity, the Mediterranean region, where human land use and, more recently, global warming, continue to promote a large-scale replacement of forests by sparsely wooded areas. To analyse how different bat species cope with this change in habitat availability, we studied bat activity and distribution on Asinara island, Sardinia. Call recordings were performed in different habitat types (forest, semi-open, open, settlement) and classified as echolocation, social call, or feeding, contacts. We checked for effects of habitat type, temperature, relative humidity, moonlight, and availability of potential prey insects on bat activity. Habitat type was the predominant factor explaining bat activity, which was highest at forest sites and lowest at open sites. Thus open-space foragers did not benefit from the ample presence of open areas. On the other hand, some edge and narrow space foragers reacted with habitat switching to forest loss. Thus, Rhinolophus hipposideros was predominant at semi-open sites, reflecting a flexible use of foraging habitats. Finally, contact types differed across habitat types with species-related preferences for social interactions and foraging activity. Our results suggest that sparsely wooded areas promote a change of bat community composition, and a loss of certain species, but also that a more balanced mix of habitat types by partial reforestation may help to maintain, and even increase, bat species diversity on Mediterranean islands.

The study was conducted in 2023 – 2024 in various seasons in the limestone mine near Parcani locality. 7 species of bats were recorded: Rhinolophus hipposideros, Myotis blythii, Myotis daubentonii, Myotis dasycneme, Myotis mystacinus, Plecotus auritus and Plecotus austriacus. The structure of bat community was different depending on the season. The highest number of individuals was registered during the hibernation period, when M. blythii was the most abundant species. All species recorded in Parcani mine are protected at national and European level. The Parcani mine is an important hibernation and summer roost for many rare bat species.

Limestone mines are the most important underground roosts for bat species in the Republic of Moldova. The aim of the paper was to first study the bat fauna of a newly registered roosting site—the limestone mine near Parcani, Soldanesti district, in the north of Moldova, in order to elucidate the diversity of bats in various phenological periods and to highlight the importance of this roost in preserving chiropteran diversity. Field studies were carried out in 2023–2024 in different seasons, according to standard methods of bat monitoring in underground roosts, in order to reveal the changes in the bat community structure thorough the year. The species diversity was relatively high, with 10 bat species recorded during the study period: Rhinolophus hipposideros, Myotis blythii, M. nattereri, M. daubentonii, M. dasycneme, M. bechsteinii, M. mystacinus, Barbastella barba¬stellus, Plecotus auritus, and Plecotus austriacus. The structure of the bat community was different depending on the season. The highest diversity and largest number of individuals were recorded in the hibernation period, when Myotis blythii was the dominant species representing over 80% of the whole bat community. During the summer season, the diversity and number were the lowest, the dominant species was again M. blythii (55.1%), followed by M. daubentonii (20.4%) and M. dasy¬cneme (14.3%). During the breeding season, the diversity and number increased significantly; M. daubentonii and M. blythii were dominant representing more than 90% of the bat community. The Parcani mine is an important roosting site for many bat species, especially in the breeding and hibernation periods. The registered hibernating colony of M. blythii was the largest among all the known colonies in underground roosts of Moldova. The critically endangered species in Moldova—M. nattereri, M. bech-steinii, and B. arbastellus—were registered in the cold period. For M. nattereri and B. barbastellus, it is the second record locality in the territory of the republic. All species recorded in the Parcani mine are protected at national level in Moldova and in neighbouring countries, while the species Myotis blythii, M. dasycneme, M. bechsteinii, Barbastella barbastellus, and Plecotus austriacus are protected at a European level.

Data on species composition and abundance of bats during hibernation surveyed in the winter of 2024 in 12 cave-type shelters are presented. During these studies, 7 species of bats were found in hibernation. As in previous years, the most numerous species was the lesser horseshoe bat. Another 3 species, the greater mouse-eared bat, Daubenton's bat, and the brown long-eared bat were found in several shelters in small numbers. Three species (Myotis nattereri, M. mystacinus, and Plecotus austriacus) were found in one individual each. Two species (Barbastella barbastellus and Eptesicus serotinus), which were found during the 2021 survey, were not found in 2024. A comparison of the 2021 and 2024 survey data shows a stable abundance of winter aggregations of the thermophilic lesser horseshoe bat and a reduction in the number of cold-loving species, which is likely caused by a stable trend of increasing winter temperatures.

The recent COVID-19 pandemic has renewed interest in bats, as they are natural hosts for numerous viruses, some of which have crossed species boundaries. Despite continued efforts in the past, the ecology of bat-related viruses in a significant part of national territories, such as Italy, remains largely unexplored. Herein, we describe the detection and molecular characterization of bat coronaviruses, identified during a viral survey on selected potential zoonotic pathogens (lyssavirus and coronaviruses) carried out in Sicily, southern Italy. A total number of 330 samples were collected from 149 bats in a period (November 2020-April 2023) overlapping the COVID-19 pandemic. All samples tested negative for lyssavirus and SARS-CoV-2, while 12 bats (8.05%) tested positive to a pan-coronavirus assay. Both alphacoronaviruses and betacoronaviruses were identified in samples from three species (Miniopterus schreibersii, Rhinolophus ferrumequinum, and Rhinolophus hipposideros). Strain sequences were related to coronaviruses detected in the last decade in northern Italy as well as in other countries bordering the Mediterranean basin, suggesting a widespread diffusion of these strains. This study supports the need for further monitoring efforts and early detection of circulating coronavirus genotypes, particularly for those which have been repeatedly emerging as zoonotic spillovers.

At the size of a thumb (3,7-4,5 cm) and a weight of 4-7 g, the lesser horseshoe bat (Rhinolophus hipposideros Bechstein, 1800) is the smallest Rhinolophidae in Bavaria and Tyrol. Once widespread in Europe, the species suffered massive population declines in the second half of the 21st century and became extinct in some countries. For future conservation programs, it is important to understand the major regional causes of extinction. This study compares extinct and active maternity roosts concerning the availability of roof trusses, the amount of woodland (broadleaved and total woodland), as well as environmental contaminants, that is, persistent organic pollutants from the air (lindane, DDD, DDE, DDT, and pentachloroanisole) and the heavy metals lead (Pb) and cadmium (Cd) found in feces (guano). The current records of extinct sites reveal that 29.5% of the buildings are inaccessible for R. hipposideros because of closed entrances. Loss of maternity roosts plays a major role in survival and reproductive success of this site-fixated and sensitive bat species. Linear models indicated an influence of Cd concentration and broadleaf cover on colony size. Virtually all quarters contained residues of wood treatment with lindane, pentachlorophenol (residue pentachloroanisole), and, in some cases, DDT (Dichlordiphenyltrichlorethan). Generalized Linear Models indicated an influence of Pb and pentachloroanisole concentrations on whether colonies went extinct or persistedThe study revealed Pb concentrations above 11 µg/g in feces to be exclusive to extinct colonies and thus potentially critical to colony survival. In sum, suitable roosting sites that have more than 9% deciduous forest cover within a 0.5 km radius andwith low Pb and Cd levels in the soil and proximity to other roosting sites are crucial for the lesser horseshoe bat. Due to the demanding habitat requirements of this sensitive species, it cannot be excluded that other factors intensify population declines. Future studies could explore the influence of light pollution and the change of land cover in relation to population sizes.

Exposure assessment of metals in cave-dwelling bats: Worldwide relevance of local knowledge.

This work represents an important contribution to the continuous documentation of bats in the Albanian part of Prespa Lakes (with a total of 33 sites visited). Throughout these surveys conducted in four seasons, from 2023 to 2024, various locations such as caves, tunnels, bunkers, buildings, forested areas and bridges were monitored. This effort led to identifying 13 bat species, some of which are rarely seen in this region. These species include Hypsugo savii, Miniopterus schreibersii, Myotis bechsteinii, Myotis daubentonii, Myotis mystacinus, Myotis nattereri/emarginatus, Myotis capaccinii, Nyctalus leisleri, Pipistrellus nathusii, Pipistrellus pipistrellus, Rhinolophus ferrumequinum, Rhinolophus hipposideros, Rhinolophus euryale, and possibly other medium-sized Rhinolophus species. The data collected highlight the high diversity of bat species and roosting sites in this part of the country. Notably, significant colonies of Mi. schreibersii, M. capaccinii, Rh. hipposideros, Rh. ferrumequinum, and mediumsized Rhinolophus were discovered. A combination of visual observations and mist netting was used. This study identified 17 sites showing current or previous signs of bat presence, with up to eight different species observed at one site and more than 3,140 bat specimens counted in a single season, shedding light on the most significant roosting sites and hibernacula in the area. Furthermore, the research presents data on the existing threats to bats and their habitats, along with recommendations for future conservation efforts.

Prince Mohammed bin Salman Royal Reserve (PMBSRR or the Reserve) is located in the northwest of Saudi Arabia and covers an area of 24,500 km2 of both marine and terrestrial ecosystems. Bat surveys have been undertaken between 2022 and 2024 across PMBSRR as part of the Reserve’s groundbreaking conservation efforts and this is the first published checklist of the bat species present within the Reserve. Survey methods included bat capture, roost inspection, and acoustic recordings. Tissue and faecal samples were taken during the surveys and compared to a global database to confirm the species present. The survey results confirmed the presence of 18 species belonging to 14 genera of eight families. This research has greatly expanded our knowledge on the diversity of bats within the Kingdom, increasing the reported bat species in the Tabuk region by seven species, with the addition of Rhyneptesicus nasutus, Rhinolophus hipposideros, Nycteris thebaica, Tadarida aegyptiaca, Rhinopoma microphyllum, Taphozous nudiventris, and Taphozous perforatus and increasing the number of species within Saudi Arabia by one species, with the addition of Vansonia rueppellii.

At the 3’ end of the C2 gene in the mammalian TRB locus, a distinct reverse TRBV30 gene (named TRBV31 in mice) has been conserved throughout evolution. In the fully annotated TRB locus of 14 mammals (including six orders), we observed noteworthy variations in the localization and quality of the reverse V30 genes and Recombination Signal Sequences (RSSs) in the gene trees of 13 mammals. Conversely, the forward V29 genes and RSSs were generally consistent with the species tree of their corresponding species. This finding suggested that the evolution of the reverse V30 gene was not synchronous and likely played a crucial role in regulating adaptive immune responses. To further investigate this possibility, we utilized single-cell TCR sequencing (scTCR-seq) and high-throughput sequencing (HTS) to analyze TCRβ CDR3 repertoires from both central and peripheral tissues of Primates (Homo sapiens and Macaca mulatta), Rodentia (Mus musculus: BALB/c, C57BL/6, and Kunming mice), Artiodactyla (Bos taurus and Bubalus bubalis), and Chiroptera (Rhinolophus affinis and Hipposideros armige). Our investigation revealed several novel observations: (1) The reverse V30 gene exhibits classical rearrangement patterns adhering to the ‘12/23 rule’ and the ‘D-J rearrangement preceding the V-(D-J) rearrangement’. This results in the formation of rearranged V30-D2J2, V30-D1J1, and V30-D1J2. However, we also identified ‘special rearrangement patterns’ wherein V30-D rearrangement preceding D-J rearrangement, giving rise to rearranged V30-D2-J1 and forward Vx-D2-J. (2) Compared to the ‘deletional rearrangement’ (looping out) of forward V1-V29 genes, the reverse V30 gene exhibits preferential utilization with ‘inversional rearrangement’. This may be attributed to the shorter distance between the V30 gene and D gene and the ‘inversional rearrangement’ modes. In summary, in the mammalian TRB locus, the reverse V30 gene has been uniquely preserved throughout evolution and preferentially utilized in V(D)J recombination, potentially serving a significant role in adaptive immunity. These results will pave the way for novel and specialized research into the mechanisms, efficiency, and function of V(D)J recombination in mammals.

The lesser horseshoe bat, last seen in Luxembourg in the winter of 1992, has been listed as extinct on the Red List since 2002. However, following the reopening of the entrance of an ironmine near Lasauvage (Minette), close to the French border, acoustic monitoring detected the species on six occasions between September and October 2022. Further studies in 2023 and 2024 near to Lasauvage in Fond de Gras revealed the use of this site at least as migrating corridor and hibernation in the old mines is very likely. These discoveries represent the first evidence of the lesser horseshoe bat in Luxembourg since 30 years.

The Quaternary record of fossil bats in the Iberian Peninsula and the Balearic Islands: Palaeobiogeographical changes and palaeoenvironmental implications

Behavioral responses of cave-roosting bats to artificial light of different spectra and intensities: Implications for lighting management strategy