Bat Species Composition Research Articles

Summer chiropteran community in the Sergievka Park with the unique dominance of Pipistrellus nathusii on the northern periphery of its distribution range

The study of species on the periphery of their ranges is especially relevant for long-term research in protected areas. The aim of this study is to test the hypothesis that Pipistrellus nathusii on the northern periphery of its range has a clumped distribution with long-term viable breeding centres. The species composition and relative abundance of bats in the park were determined through capturing them with mist nets during the 1997–1998 and 2020–2022 survey periods. Within the 2nd survey period the use of an ultrasonic detector was additionally involved. Stability of the bat species composition in the protected area and a significant difference in the relative abundance between the surveys were revealed (χ2 = 47.31, p < 0.05). During both periods, the bat community in the park exhibited a pronounced dominance of P. nathusii and stable values of its relative abundance (40.7 and 44.2%, respectively). Perennial nursery colonies of Myotis daubentonii, Nyctalus noctula, and P. nathusii have been discovered in the park, which are arguably among the northernmost findings (59.89° N, 29.88° E) in European Russia. The catch rate (6.3 bats per net-night) and acoustic activity of the Chiroptera (16.6 active minutes per detector-hour) on the pond was significantly higher than on the alley and glade. This pattern is typical for all frequently recorded bat species – P. nathusii, N. noctula and Eptesicus nilssonii. According to the results of multiple analysis of variance, the effect of species on acoustic activity was the greatest (η = 24.59%, F = 15.52, p < 0.001). The impact of the habitat and the time since sunset, as well as the pairwise combined impact of these three factors, was also significant and reliable. The sizes of the nursery colonies were determined, which in P. nathusii were record high for the northern periphery of the breeding range, 212 individuals. Evening departures of P. nathusii from the nursery colony on the alley were characterized by their beginning before sunset, and from the nursery colony in the glade after sunset. The intensity of P. nathusii departure from the colony in the forest part of the park is significantly higher (5.3 bats/ min) than in the glade (1.4 bats/min). The fact that large nursery colonies of P. nathusii have existed for decades locally at 60° N latitude suggests the species may have a wider distribution in Eastern Fennoscandia in transformed areas containing old trees. Keywords: bats; South-Eastern Fennoscandia; relative abundance; nursery colonies; acoustic activity; circadian rhythms

The Influence of Urbanization on Bat Species Composition and Activity in Baton Rouge, Louisiana

The Influence of Urbanization on Bat Species Composition and Activity in Baton Rouge, Louisiana

Exceptionally Uniform Bat Assemblages across Different Forest Habitats Are Dominated by Single Hyperabundant Generalist Species

Woodland bat assemblages are usually structured in a space according to the distance from the ground, water, and obstacles, features that often define chiropteran hunting tactics. Consequently, the bat species composition differs strongly among various habitats, even within the same forest patch. However, when conducting local bat surveys in Wolin National Park (WPN), we revealed an unexpected uniformity in the qualitative and quantitative structure of bat assemblages, based on mist netting and ultrasound recording. In total, 10 vespertilionid species were detected. Across all methods and sampled habitats, a single species, Pipistrellus pygmaeus, predominated, while no Barbastella barbastellus, an old forest specialist, were detected, despite the abundance of their preferred daily roosts. We also reviewed the literature for mist-netted bat samples in four different habitats in lowland Polish forests. The samples usually clustered based on habitats, and the same habitat classes often clustered very closely despite representing geographically distant forests. The exception was WPN, where all four habitat classes formed a tightly packed cluster. We hypothesize that P. pygmaeus might act as a hyperabundant native species, a successful generalist that reduces the contribution of more specialized taxa in the assemblage. It probably benefits from both forest renaturation and anthropogenic cross-boundary subsidy.

The effect of urbanization on species composition and trophic guilds of bats (Mammalia, Chiroptera) in the Brazilian Savanna.

Urban environments present less environmental heterogeneity in relation to the natural ones, affecting the biodiversity of bats and the ecological processes in which they participate. In this way, we will identify how urbanization influences the structure of bat communities in the municipality of Goiânia, Goiás, Brazil. We compared species composition, guilds and bat richness in a gradient that crossed urban, semi-urban and natural areas in the municipality of Goiânia, contained in the Cerrado biome. We captured a total of 775 bats of 16 species distributed in three families. Urban areas had a higher species abundance, while semi-urban areas had a higher species richness. The three types of environments have different compositions, the urban one being more homogeneous, the fauna in these areas is composed of generalist species, which benefit from this process. The diversity present in semi-urban areas is a consequence of the intersection between urban and natural fauna, which is why urban expansion needs to occur in a planned manner to minimize the impacts of this process and ensure the maintenance of biodiversity.

Experience in Using an Echo Meter Touch Ultrasonic Module in Studies of the Species Composition, Occurrence, and Biotopic Preferences of Bats (Chiroptera, Vespertilionidae) in Voronezh Oblast

Experience in Using an Echo Meter Touch Ultrasonic Module in Studies of the Species Composition, Occurrence, and Biotopic Preferences of Bats (Chiroptera, Vespertilionidae) in Voronezh Oblast

Factor analysis of the Wind Farm LLC wind park (Donetsk region, Ukraine) impact on bats based on the index of their activity and dynamics of species diversity

In 2019-2020, research on the vocal activity of bats was carried out on the territory of the Wind Farm LLC wind park (800 MW), which is planned to be built near Mariupol (Donetsk region, Ukraine). There were used three methods of material collection: research on the vantage points, on transects and at a stationary point throughout the night. The total number of registered voices is 1554 signals, 695 of which are recorded in 2019 and 859 in 2020. The article shows the dynamics of voice activity by seasons and phases of the life cycle. Based on the activity index of mice, the dynamics of this indicator by months is shown. Forage and migratory behaviour of bats, calculated by determining the index of their activity, shows the average values. An analysis of the territorial distribution shows that bats confined to settlements and open water bodies. The species composition of bats, identified for 1235 signals registered in the territory of the projected wind farm, is stable and represented by widespread at least 10 species belonging to 6 taxonomic ranks. There were revealed some wind turbine generators near which the implementation of minimization measures is required. In total, according to forecasts, there are 10-16 such wind turbine generators within the Wind Farm LLC wind park. Monitoring the state of bats in the project area both during the construction of the wind farm and its operation is mandatory for the development and implementation of measures to minimize the possible negative impact on bats.

Comparison of alien Robinia pseudoacacia stands with native forest stands across different taxonomic groups

There is much knowledge about the impact of non-native Robinia pseudoacacia on native ecosystems, but mostly it is related to one group of organisms. In this article, we provide an analysis of the impact of R. pseudoacacia on the surrounding biota with a broader scope in a model area with homogeneous abiotic conditions compared and analysed by the twin plots method. Microclimatic conditions and the changes in the species composition of vegetation, terrestrial gastropods, carabid beetles, bats, and acoustic diversity were analysed. The planted Robinia stands were always brighter and warmer and had lower canopy closure than the control plots in the native floodplain forest. More nitrogen and phosphorus were recorded in the soil of the Robinia stands. The floristic composition changed the most based on the planting of Robinia trees. Compared to those in the adjacent floodplain forest, more heliophilous neophytes, archaeophytes and grasses were found. Assemblages of gastropods and carabid beetles were less affected by the planting of Robinia trees and more by the microclimatic conditions of the studied locality. The number of recorded bats and acoustic diversity were higher in native floodplain forests due to food and shelter options.All results show that the planting of Robinia trees changes the microclimatic conditions and species composition of forest stands. The warmer and less humid environment under Robinia stands is not desirable in the face of ongoing climate change. The alien (including invasive) and ruderal plant species in the understorey are supported due to the more favourable brighter conditions and nitrogen fixation in the soil. Additionally, the other groups of organisms react negatively to changes under Robinia trees in terms of microclimatic conditions, food and shelter sources. Therefore, forest managers, policy-makers and conservation workers should choose stratified management when deciding whether and where to plant R. pseudoacacia.

Do Bats Avoid the Urban Core in the Breeding Season? A Case Study from Temperate Latitudes

Seasonal utilization of urban areas by bats remains inadequately explored. This study aimed to comprehensively survey the species composition and population dynamics of bats during both the breeding season (May–July) and autumn migration season (August–September) within a large urban area, specifically Kharkiv city, Ukraine. We conducted multiyear data collection from 2014 to 2016, employing a combination of acoustic recordings, mist-netting, and registration of opportunistically found bats. The results revealed the identification of seven bat species using all methods (Eptesicus serotinus, Nyctalus noctula, N. leisleri, Pipistrellus pygmaeus, P. kuhlii, P. nathusii, and Vespertilio murinus), with notable differences in species composition between the studied periods. During the migration season, N. noctula was a numerically predominant species, while P. kuhlii and E. serotinus were the most abundant during the breeding season. The urban core bat population during the breeding season primarily consisted of males and solitary reproductive females, mainly represented by P. kuhlii and E. serotinus. Acoustic recording data indicated that N. noctula actively avoided the urban core during the breeding season, but was more common on the city periphery. In contrast, during the migration season, the city experienced a significant surge in bat abundance, both in general and specifically among noctule bats, with their numbers increasing tenfold compared to the breeding season. Moreover, a considerable number of young individuals were observed during the migration season. These findings provide evidence that bats tend to avoid the urban core in large cities at temperate latitudes during the breeding season but actively utilize urban areas during autumn migration. Understanding the seasonal preferences and movements of bats in urban environments is crucial for effective conservation and management strategies.

The efficacy of performing field surveys during the dry and rainy seasons to estimate species richness and composition of local bat assemblages

AbstractHere we assessed the efficacy of performing field surveys during both dry and rainy seasons to estimate species richness and composition of phyllostomid bats in 12 sites of the Brazilian Atlantic Forest. Our goal was to elucidate two opposite scenarios. If bat species compositions differ between the dry and rainy seasons, then field surveys in both seasons will be considered complementary for estimating local bat assemblages. In contrast, if bat species compositions in the dry season are a nested subset of the species present in the rainy season, then field surveys in both seasons will be considered redundant. Our results showed that field surveys performed only during the rainy season exhibited the same efficacy in recording bat species as field surveys considering both dry and rainy seasons combined. Consequently, the rare species sampled in the rainy season contributed to the uniqueness of communities in terms of species composition. Considering that time, funding, and the number of field personnel available for work are important factors when determining the sampling effort in highly biodiverse regions like the tropics, our results can be useful in establishing protocols for research projects with limited resources aiming to create a comprehensive list of species.

Large‐scale long‐term passive‐acoustic monitoring reveals spatio‐temporal activity patterns of boreal bats

The distribution ranges and spatio‐temporal patterns in the occurrence and activity of boreal bats are yet largely unknown due to their cryptic lifestyle and lack of suitable and efficient study methods. We approached the issue by establishing a permanent passive‐acoustic sampling setup spanning the area of Finland to gain an understanding on how latitude affects bat species composition and activity patterns in northern Europe. The recorded bat calls were semi‐automatically identified for three target taxa; Myotis spp., Eptesicus nilssonii or Pipistrellus nathusii and the seasonal activity patterns were modeled for each taxa across the seven sampling years (2015–2021). We found an increase in activity since 2015 for E. nilssonii and Myotis spp. For E. nilssonii and Myotis spp. we found significant latitude ‐dependent seasonal activity patterns, where seasonal variation in patterns appeared stronger in the north. Over the years, activity of P. nathusii increased during activity peak in June and late season but decreased in mid season. We found the passive‐acoustic monitoring network to be an effective and cost‐efficient method for gathering bat activity data to analyze spatio‐temporal patterns. Long‐term data on the composition and dynamics of bat communities facilitates better estimates of abundances and population trend directions for conservation purposes and predicting the effects of climate change.

Urban wildflower meadow planting for biodiversity, climate and society: An evaluation at King's College, Cambridge

Abstract The biodiversity and climate crises are critical challenges of this century. Wildflower meadows in urban areas could provide important nature‐based solutions, addressing the biodiversity and climate crises jointly and benefitting society in the process. King's College Cambridge (England, UK) established a wildflower meadow over a portion of its iconic Back Lawn in 2019, replacing a fine lawn first laid in 1772. We used biodiversity surveys, Wilcoxon signed rank and ANOVA models to compare species richness, abundance and composition of plants, spiders, bugs, bats and nematodes supported by the meadow, and remaining lawn, over 3 years. We estimated the climate change impact of meadow vs lawn from maintenance emissions, soil carbon sequestration and reflectance effect. We surveyed members of the university to quantify the societal benefits of, and attitudes towards, increased meadow planting on the collegiate university estate. In spite of its small size (0.36 ha), the meadow supported approximately three times more plant species, three times more spider and bug species and individuals, and bats were recorded three times more often over the meadow than the remaining lawn. Terrestrial invertebrate biomass was 25 times higher in the meadow compared with the lawn. Fourteen species with conservation designations were recorded on the meadow (six for lawn), alongside meadow specialist species. Reduced maintenance and fertilising associated with meadow reduced emissions by an estimated 1.36 Mg CO2‐e per hectare per year compared with lawn. Relative reflectance increased by 25%–34% for meadow relative to lawn. Soil carbon stocks did not differ between meadow and lawn. Respondents thought meadows provided greater aesthetic, educational and mental wellbeing services than lawns. In open responses, lawns were associated with undesirable elitism and social exclusion (most colleges in Cambridge restrict lawn access to senior members of college), and respondents proved overwhelmingly in favour of meadow planting in place of lawn on the collegiate university estate. This study demonstrates the substantial benefits of small urban meadows for local biodiversity, cultural ecosystem services and climate change mitigation, supplied at lower cost than maintaining conventional lawn.

ПЕРВАЯ НАХОДКА NYCTALUS LEISLERI (KUHL, 1817) (CHIROPTERA, VESPERTILIONIDAE) В МОРДОВСКОМ ГОСУДАРСТВЕННОМ ЗАПОВЕДНИКЕ (ЕВРОПЕЙСКАЯ РОССИЯ)

Nowadays, the fauna of bats of protected areas in the Republic of Mordovia is poorly studied. We have investigated the species composition and abundance of bats in the Mordovia Nature Reserve in JulyAugust 2021, 2022. In total, 986 individuals of 10 bat species were caught. The habitation in the reserve of nine bat species previously known were confi rmed. For the fi rst time, the habitation of a new species in the nature reserve, the lesser noctule Nyctalus leisleri (Kuhl, 1817) (Chiroptera, Vespertilionidae), was revealed. The results of counts of bat fauna in the Mordovia Nature Reserve are presented.

Insectivorous Bats in Eastern Mediterranean Planted Pine Forests—Effects of Forest Structure on Foraging Activity, Diversity, and Implications for Management Practices

Bats are primarily forest mammals and forest structure may affect their communities through the level of vegetation clutter. Pine plantations are typically even-aged managed forests that lack structural complexity. However, an understory layer can enhance the heterogeneity of these forests, making them suitable for several animal taxa. We hypothesized that species composition, richness, and foraging activity of insectivorous bats in pine plantations vary according to forest structure, specifically with the density of the understory. We measured pine density, Diameter at Breast Height (DBH), canopy closure, and vegetation cover of 29 pine (Pinus halepensis) plantations of the Judean Lowlands, Israel, and collected acoustic data on resident bats. We found that bat species richness and total activity increased in forests with large tree DBH and dense shrubs. Cluttered-habitat species foraged preferentially in forests with large tree DBH and high pine density, while open-habitat species preferred forests with well-developed canopies and dense shrubs. Pipistrellus pipistrellus and Eptesicus serotinus foraged in mature forests with well-developed bushes and these species are endangered in Israel. We conclude that mature planted pine forests with a well-developed under-canopy are suitable foraging grounds for insectivorous bats. Management plans for planted pine forests should consider our findings to support bat populations, including rare and endangered species.

Species Composition of Bats in Brazilian Restingas: Testing Environmental Versus Geographical Hypotheses for Community Composition

Restingas are ecosystems located in the coastal regions of the Atlantic forest, characterized by heterogeneous vegetation of sandy soil. This region has historically come under severe human pressure, and a large portion of these areas have been lost or degraded. The mammalian fauna of restingas is poorly known particularly for bats. This lack of information prevents a better understanding of the biological processes affecting bats and restingas and may severely impair conservation actions. Here we analyze bat species composition, richness, and similarity in 17 restingas sites in Brazil to check whether bat community composition is correlated with geographic distance among sites. We conducted an extensive survey of a published scientific literature to gather data and have a picture of the current knowledge on restinga bats. Until now, 40 bat species are documented in the restingas ecosystems. The richest restinga was in Jurubatiba National Park, and those with the lowest species richness were in Ilha de Cabo Frio, Saquarema, and Barra de Maricá. We found no relationship between geographic distance and dissimilarity on species composition among restingas sites. Although much attention has been paid to sampling this area, it has not been sampled uniformly. In fact, restingas have been undersampled causing a lack of recognition of how important these areas are biologically.

Multifaceted DNA metabarcoding of guano to uncover multiple classes of ecological data in two different bat communities.

DNA contained in animal scat provides a wealth of information about the animal, and DNA metabarcoding of scat collections can provide key information about animal populations and communities. Next‐generation DNA sequencing technologies and DNA metabarcoding provide an efficient means for obtaining information available in scat samples. We used multifaceted DNA metabarcoding (MDM) of noninvasively collected bat guano pellets from a Myotis lucifugus colony on Fort Drum Military Installation, New York, USA, and from two mixed‐species bat roosts on Fort Huachuca Military Installation, Arizona, USA, to identify attributes such as bat species composition, sex ratios, diet, and the presence of pathogens and parasites. We successfully identified bat species for nearly 98% of samples from Fort Drum and 90% of samples from Fort Huachuca, and identified the sex for 84% and 67% of samples from these same locations, respectively. Species and sex identification matched expectations based on prior censuses of bat populations utilizing those roosts, though samples from some species were more or less common than anticipated within Fort Huachuca roosts. Nearly 62% of guano samples from Fort Drum contained DNA from Pseudogymnoascus destructans, where bats with wing damage from White‐nose Syndrome were commonly observed. Putative dietary items were detected in a majority of samples from insectivorous bats on Fort Drum (81%) and Fort Huachuca (63%). A minority of guano samples identified as the nectarivorous Leptonycteris yerbabuenae (28%) provided DNA sequences from putative forage plant species. Finally, DNA sequences from both putative ecto‐ and endoparasite taxa were detected in 35% and 56% of samples from Fort Drum and Fort Huachuca, respectively. This study demonstrates that the combination of noninvasive sampling, DNA metabarcoding, and sample and locus multiplexing provide a wide array of data that are otherwise difficult to obtain.

DẪN LIỆU MỚI VỀ ĐẶC ĐIỂM HÌNH THÁI VÀ TIẾNG KÊU SIÊU ÂM CỦA CÁC LOÀI DƠI THUỘC GIỐNG MYOTIS (MAMMALIA: CHIROPTERA: VESPERTILIONIDAE) Ở MIỀN BẮC VIỆT NAM

Among the currently known bat species composition recorded from Vietnam, 12 species of Myotis distribute in the northern region: Myotis altarium, M. alticraniatus, M. annamiticus, M. annectans, M. chinensis, M. hasseltii, M. horsfieldii, M. indochinensis, M. laniger, M. montivagus, M. muricola và M. pilosus. Data on these Myotis species, particularly echolocation, is limited because almost all of them have been rarely recorded over the field surveys. Between 2020 and 2021, we conducted a series of bat surveys in northern Vietnam with an emphasis on Myotis species. Results from our studies included new data in morphology and echolocation of three species: Myotis alticraniatus, M. muricola and M. pilosus. External measurements of these species from Ha Long Bay are larger than those in previous publications. Their echolocation parameters (start frequency, end frequency, call duration) also differ from those in published descriptions. This paper provides new records of the three Myotis species from Ha Long Bay for further research, monitoring and conservation actions in the future.

Effects of Pine Forest Management Practices on Bat Functional Traits in a Subtropical Region

Changes in landscape environmental characteristics may influence habitat use by bat species as well as species composition and community functional structure. Landscape features may drive the functional role variability of bat species on the ecosystems. Consequently, landscapes may change the degree of functional differentiation between species. We have evaluated the effect of pine forest monoculture and their environmental characteristics on the distribution and functional attributes of bat species. We sampled bat communities in areas with high (three sites) and low (three sites) forest land use management practices including six mist-netting locations in order to sample for bats at each site. In addition, we have also measured temperature, humidity, percentage of land use coverage (managed forest, agriculture, and native forest), and percentage of canopy openness at each site. We captured 87 bats belonging to eight species representing two families: Phyllostomidae and Vespertilionidae. For the functional analysis, we used three functional attributes to describe wing morphology: wing loading, aspect ratio, and forearm length. No significant effect of any environmental variable was observed on bat species composition. However, bat species distribution was driven by the ability associated with their functional attributes to occupy the space. Moreover, forearm length was positively correlated with forest cover, canopy openness, and humidity. Species with similar wing morphology have responded in a similar way to environmental variables in the studied areas. Functional dispersion was high in the native forest. The monoculture of exotic species may increase the functional attributes related with vulnerability as described by bat wing morphology. Therefore, the native forest conversion to pine forest monoculture may increase the loss of functional attributes in the bat community.

Fauna and flight activity of bats in natural forests in the southern Brdy Mts. and the first information on the occurrence of Hypsugo savii in this area (Chiroptera: Vespertilionidae)

The bat fauna was studied at six localities of protected natural forest fragments in the southern part of the Brdy Mts. (south-western Bohemia), in the years 2019–2020. Netting and acoustic detection on line transects were used in order to document the species composition and flight activity of bats at the localities under study. Altogether, 24 individuals of seven bat species were netted. In total, 643 minutes of the presence of flying bats were registered within 56.5 transect hours. With use of these methods, at least 16 bat species were recorded. Of them, Myotis myotis, M. mystacinus / M. brandtii, M. nattereri, Eptesicus nilssonii, Pipistrellus pipistrellus, Plecotus auritus, and Barbastella barbastellus represent the constant species group with respect to their occurrence at the localities. Pipistrellus pipistrellus was the most frequent species (54%), with the highest relative flight activity at all localities. The highest intensity of flight activity of the bat community was observed in habitats with rocks, boulder accumulation, and open stony debris (14.17 min+/h). The highest bat species diversity was registered in habitats with the prevalence of herb-rich mixed beech forest stands (15 species, diversity index H’=2.02; equitability E=0.75). A series of calls of Hypsugo savii was registered in the Na skalách Nature Reserve on 8 May 2020. It represents the first finding of this species in the region of the Brdy Mts.

Склад зимових агрегацій кажанів (Chiroptera) у сховищах печерного типу Тернопільського Придністер’я (обліки 2021 року)

In 2021, the authors, with the assistance of speleological clubs, conducted winter surveys of bats in underground cavities of in the Ternopil part of the Middle Dnister Region. Twenty wintering shelters of different origin and size were inspected, of which ten are described for the first time. A total of 2573 individuals of 6 species were recorded. The most abundant species (92.84%) was Rhinolophus hipposideros. The most noticeable accumulations of this species were found in the caves Kryshtaleva, Vitrova, Verteba, Yuvileyna, and Ozerna. The second most abundant species was Myotis myotis. A total of 134 individuals of this species were found, which is 5.2% of the total number of recorded bats. On the third place were Myotis daubentonii (1.1%) and Plecotus auritus (0.7%), which were found in five shelters each, albeit in small numbers. The largest number of bats was found in Kryshtaleva Cave—1188 individuals belonging to 2 species. Several hundred individuals were found during the winter in the caves Verteba and Vitrova, and more than a hundred in the caves Khomach, Juvyleyna, and Ozerna. The highest species richness was recorded in the caves Ugryn, Teklivska, and Mlynky (four species in each). There have been no noticeable changes in the abundance and species composition of bats during the winter in the underground cavities of the studied region since 2019 (at the time of preliminary surveys). It is possible to trace an increase in the abundance of Rhinolophus hipposideros in Kryshtaleva Cave, of Myotis daubentonii in Ugryn Cave, and of Plecotus auritus in several shelters. This indicates that the mode of use of caves (for scientific and recreational purposes) does not prevent them from fulfilling the role of wintering shelters for this group of animals. The Ternopil part of the Middle Dnister Region is characterized by the absolute dominance of Rhinolophus hipposideros, whereas in the neighbouring Kamenets part of the region this species ranks second in abundance after Myotis myotis. Cold-tolerant species are much more common in the Kamianets-Podilskyi area. These differences are related to the different types of the most common wintering shelters in the region.

Bats (Chiroptera) of Transnistrian underground shelters based on results of the 2020–2021 census

This report presents data on the species composition of bats inhabiting underground structures and complexes on the left bank of the Dnister River according to survey results for 2020–2021. Field studies of bats (order Chiroptera) inhabiting underground shelters of the left bank of the middle and lower reaches of the Dnister were conducted from August 2020 to October 2021. In total, we found 26 underground sites and complexes potentially suitable for bats in Transnistria and in 15 of them we counted their number and species composition. Most of the detected underground objects are of anthropogenic origin (former industrial tunnels for limestone mining and manual mining), and only 2 of natural origin — a shallow cave in the village of Rascov, Camenca District and a karst cave in the village of Mikhailovka, Rybnitsa District. The identified objects formed the basis of the first detailed cadastre of underground structures of the left bank of the Dnister and adjacent areas. Each underground facility was mapped with exact GPS coordinates and assigned a corresponding index and serial number. According to the survey results, 8 species of bats were recorded: Rhinolophus hipposideros, Myotis blythii, Myotis bechsteinii, Myotis daubentonii, Myotis dasycneme, Plecotus auritus, Plecotus austriacus, and Eptesicus serotinus. The most widespread and frequently encountered species in the studied area are the lesser horseshoe bat Rhinolophus hipposideros and Daubenton’s bat Myotis daubentonii. The rare species include the brown long-eared bat Plecotus auritus and the grey long-eared bat Plecotus austriacus. The pond bat Myotis dasycneme and Bechstein’s bay Myotis bechsteinii are considered extremely rare, and the latter has never been recorded in Transnistria before. Based on the obtained data and in order to preserve the species diversity of bats, we identified a number of underground complexes as key objects of primary importance in the life of bats during hibernation and their breeding season.