Our research projects - Bats Ukraine

Scientific research into the ecology, distribution and biology of bats is a key component of the UCRR’s work. This work is carried out both independently by specialists from our team and in collaboration with research institutes and universities in Ukraine and other countries.

In this section, we have provided as detailed an overview as possible of the areas of research, or projects, on which scientific research is currently being conducted.

1) Distribution patterns of bat species and the structure of summer bat communities in Eastern Europe

Abstract: The distribution of bats in Eastern Europe remains understudied due to the vast territories involved and the low density of researchers. However, there is a hypothesis that the forest areas of Eastern European countries are the main centre for the recovery of populations of forest-dwelling migratory bat species. For the first time, using a standardised method involving the use of mist nets, numerous sites across Ukraine and neighbouring countries were surveyed, covering various natural zones and biomes. Patterns have been identified in the distribution of species and population densities of bats depending on landscape structure and the age structure of forests. It is planned to apply this methodology for further inventorying of species composition and studying the structure of summer bat communities in Ukraine and other countries.

Main results:
Owing to the very wide geographical coverage of the surveyed areas, an inventory of the status of the giant noctule (Nyctalus lasiopterus) was carried out in the eastern part of its range (2009–2018). It was found that the species’ population had declined significantly and that it had disappeared from most of the areas where its summer populations had existed 50–70 years ago. Taking the results of these studies into account, the global conservation status of this species was revised (in 2016) in accordance with the criteria of the International Union for Conservation of Nature (IUCN) from ‘Near Threatened’ to ‘Vulnerable’.

Species have been identified that are most likely the best indicators of undisturbed or well-preserved forest ecosystems (apart from Nyctalus lasiopterus, these also include Myotis brandtii and Nyctalus leisleri).

Overall, the hypothesis that the forest areas of Eastern Europe are the main centre for the recovery of populations of forest-dwelling migratory bat species (Pipistrellus nathusii, P. pygmaeus, Nyctalus noctula, Nyctalus leisleri and Vespertilio murinus) has been confirmed.

Key publications:

Vlaschenko A., Kravchenko K., Yatsiuk Y., Hukov V., Kramer-Schadt S., Radchuk V. (2022). Bat Assemblages Are Shaped by Land Cover Types and Forest Age: A Case Study from Eastern Ukraine. Forests, 13, 1732.

Vlaschenko A., Yatsiuk Ye., Hukov V., Prylutska A., Straka T., Kravchenko K. (2021). Urban forest preserves local bat species diversity, but not forest-dweller specialists – renewed study 65 years later (Kharkiv city, Ukraine). Mammal Research. v.66 no.4 pp. 615-626.

Vlaschenko A., Kravchenko K., Prylutska A., Ivancheva E., Sitnikova E., Mishin A. (2016). Structure of summer bat assemblages in forest of European Russia. Turk J Zool., 40: 876-893.

Gukasova A., Vlaschenko A., Kosenkov G., Kravchenko K. (2011). Bat fauna and structure of bat (Chiroptera) assemblage of the National Park “Smolensk Lakeland”, Western Russia. Acta Zoologica Lituanica. Vol. 21. – N. 2: 173-180.

Gukasova A., Vlasсhenko A. (2011). Effectiveness of mist-netting of bats (Chiroptera, Mammalia) during the non-hibernation period in oak forests of Eastern Ukraine. Acta Zoologica Cracoviensia. 54A (1-2): 77-93.

Vlaschenko A., Gashchak S., Gukasova A., Naglov A. (2010). New record and current status of Nyctalus lasiopterus in Ukraine (Chiroptera: Vespertilionidae). Lynx, n. s. (Praha). 41: 209-216.

2) Monitoring of winter roosts of bats in underground passages in north-eastern Ukraine.

Abstract: Since 1999, a survey has been carried out of all known long-extending man-made underground passages in the Kharkiv region. Two systems of abandoned adits were identified, where more than 1,000 individuals of four bat species overwinter. Over a period of more than twenty years, monitoring work was carried out to record the numbers of overwintering bats. The phenology of their arrival at wintering sites and their emergence in spring has been studied. Ringing results have established a link between wintering sites and summer habitats. Unfortunately, since 2022, this research and monitoring in this area has been suspended due to the outbreak of full-scale war.

Key findings: The Lypets’ki tunnels have been included in the list of key roosts important for the conservation of bats in Europe https://www.eurobats.org/activities/intersessional_working_groups/underground_sites

The monitoring of wintering bat populations in the tunnels of the Kharkiv region is the only long-term monitoring programme for wintering bats on the Left Bank of Ukraine.

Key publications:

Vlaschenko A. (2023). Hiding behaviour of bats in sandstone mines of North-Eastern Ukraine. European Journal of Ecology. 9, (2), pp. 66-70

Vlaschenko A., Naglov A. (2018). Results of the 10-year monitoring of bat (Chiroptera: Vespertilionidae) winter aggregation from the North-eastern Ukraine (Liptsy mines, Kharkiv region). Vestnik Zoologii, 52(5):395-416

Влащенко А.С., Наглов А.В. (2006). Зимовки рукокрылых (Chiroptera: Vespertilionidae) в искусственных пещерах севера-востока Украины. Вісник Харківського національного університету ім. В.Н. Каразіна. Серія: біологія. – №729(3). -168-175.

3) The use of urbanised landscapes by bats and the formation of urbanised populations.

Abstract: The emergence and continuous growth of cities across the globe is leading to the creation of a landscape that is new to planet Earth, known as the urbanised landscape. Cities and human settlements are emerging in natural areas, radically altering them; natural vegetation and fauna are disappearing, and microclimatic conditions are changing. However, some species are able to settle and thrive in urbanised landscapes. Bats are one of the groups of animals that successfully colonise urban and suburban areas, establishing stable populations there. The process of bats colonising built-up areas has been actively ongoing for the past 70–50 years. Using a wide range of methods—namely, the collection and rescue of animals from human dwellings, trapping with web nets, and acoustic surveys—the species composition of bats in Ukrainian cities is being monitored.

This area of research comprises several distinct sub-areas, namely: 1) long-term trends in changes to the species composition and population structure of urban bat populations; 2) seasonal changes in population structure and the specific ways in which different bat species utilise the urban environment at various stages of their annual life cycle; 3) the impact of military operations (urban destruction) on urban bat populations located near or directly on the front line, 4) the movement of bats between and beyond urban areas, as potential new routes for the transmission of pathogens and parasites.

The key research question in this area is whether the emergence of new bat species in cities and their establishment of stable populations represents an adaptation to the ‘recently’ formed urban environment, or whether it is an example of an ecological trap.

Key findings:

Research into bat populations in urban environments is one of the Laboratory’s key areas of work. Following several decades of monitoring and active research into bats in Kharkiv, the city’s territory is the most thoroughly studied in terms of the distribution, species composition and seasonal dynamics of bats. For example, by analysing stable hydrogen isotopes, we have been able to track long-term changes in the population structure of Nyctalus noctula, specifically the history and potential mechanisms behind the establishment of resident populations of this species in cities across Eastern Europe. Thanks to a well-established system for monitoring bat sightings in towns and cities across Ukraine, it is possible to promptly identify new species for particular regions or changes in the status of these species.

In response to the challenge posed by the large numbers of bats found in towns and cities that needed rescuing, a bat rehabilitation centre was established in Kharkiv. Over the years, this centre has evolved into a nationwide initiative and has become the most significant bat rescue centre in Eastern Europe.

Key publications:

Vlaschenko A., Rodenko O., Hukov V., et al. (2023). Do Bats Avoid the Urban Core in the Breeding Season? A Case Study from Temperate Latitudes. Diversity. 15, 967.

Vlaschenko, A., Shulenko, A., But, A., et al. (2023). The war-damaged urban environment becomes deadly trap for bats; case from Kharkiv city (NE Ukraine) in 2022. Journal of Applied Animal Ethics Research. 5, 1-23.

Vlaschenko A., Hukov V., Timofieieva O., et al. (2023). Leaping on urban islands: further summer and winter range expansion of European bat species in Ukraine. European Journal of Ecology. 9: 1, 70-85.

Prylutska, A., Yerofeieva, M., Bohodist, V., et al. (2023). The dataset of bat (Mammalia, Chiroptera) occurrences in Ukraine collected by the Ukrainian Bat Rehabilitation Center (2011-2022). Biodiversity Data Journal 11: e99243.

Vlaschenko A., Yatsiuk Ye., Hukov V., et al. (2021). Urban forest preserves local bat species diversity, but not forest-dweller specialists – renewed study 65 years later (Kharkiv city, Ukraine). Mammal Research. v.66 no.4 pp. 615-626

Hukov V. Timofieieva, O., Prylutska, A., et al. (2020). Wintering of an urban bat (Pipistrellus kuhlii lepidus) in recently occupied areas. European Journal of Ecology. 6: 1, 102-120.

Kravchenko K., Vlaschenko A., Lehnert L., Courtiol A., Voigt C. (2020). Generational shift in migratory bats: first-year males lead the way to northward range expansion of wintering sites. Biology Letters. 16: 9.

Vlaschenko A., Prylutska, A., Kravchenko, K., et al. (2020). Regional recapture of bats (Chiroptera, Vespertilionidae) ringed in Eastern Ukraine. Zoodiversity, 54(1): 53-66.

Vlaschenko A., Kovalov V., Hukov V. Kravchenko K., Rodenko O. (2019). An example of ecological traps for bats in the urban environment. European Journal of Wildlife Research, 65: 20.

Kravchenko K., Vlaschenko A., Prylutska A., Rodenko O., Hukov V., Shuvaev V. (2017). Year-round monitoring of bat records in an urban area: Kharkiv (NE Ukraine), 2013, as a case study. Turk J Zool., 41: 530-548.

Влащенко А.С. (2002). Находки рукокрылых в здании Харьковского национального университета. Вісник Харківського університету № 551. Серия: “Актуальні проблеми сучасної науки в дослідженнях молодих вчених м. Харкова”. Частина 2.: 212-216.

Влащенко А.С. (1999). Находка вечерницы рыжей Nyctalus noctula на зимовке в Харькове. Вестник зоологии. 33(4-5): 76.

4) Cellular immunology of chiropterans: a description of basic leukocyte parameters.

Abstract: The immune system of chiropterans remains very poorly understood. On the one hand, it is well known that it is precisely thanks to their unique immune system that bats are resistant to many viruses that are lethal to other mammalian species. On the other hand, bats are highly susceptible to bacterial and fungal pathogens, which in turn lead to mass mortality among these mammals. The immune system acts as a barrier that prevents pathogens from spreading beyond the organism, the population or the species as a whole. Changes or malfunctions in the immune system of individual animals can lead to outbreaks and the spread of infectious diseases. Consequently, the state of the immune system in animals that are carriers of pathogens must be characterised and monitored. However, even the basic parameters of the immune system in European bat species remain understudied. For example, there are no reference ranges for leukocyte parameters, such as those used to diagnose diseases in humans, domestic animals and farm animals. The aim of this line of research is precisely to describe the baseline leukocyte parameters as an indicator of the immune system status in bats, by collecting samples from as many species as possible, taking into account the animals’ condition and the season of the year.

Key findings:

This is the first description of the haematological and leukocyte parameters of chiropteran species living in areas of chronic radioactive contamination (the Chernobyl Exclusion Zone and the vicinity of the town of Pripyat). The levels of in vivo contamination in the animals were compared with their leukocyte parameters.

The largest database in Europe of blood smears from bats, in which leukocyte parameters have been analysed, has been compiled.

Key publications:

Tovstukha I., Fritze M., Kravchenko K. et al. (2024). Pilot study suggests cellular immunity changes in bats from urban landscapes, 15 January 2024, PREPRINT (Version 1) available at Research Square.

Tovstuha I., Kovalov V., Timofieieva O., Vlaschenko A. (2021). Effect of 90Sr and 137Cs concentration on hematological parameters of bats in Chernobyl Exclusion Zone (Ukraine). Acta Chiropterologica. 23(2): 371-376

5) Study of ectoparasites of bats and screening for viral and bacterial agents.

Abstract: Bats are traditionally regarded as an important reservoir of viral infections that are life-threatening to most other groups of mammals, yet pose no such threat to the bats themselves. Therefore, the screening of samples (primarily faeces, urine and saliva) obtained from bats is a vital component of assessing epidemiological threats and, more generally, monitoring viruses and other pathogenic and non-pathogenic microorganisms. In the absence of sufficiently well-equipped genetic laboratories in Ukraine, research partners in these studies include scientific groups in other countries, primarily Germany, Hungary and Finland. An equally important area of this research is the study of ectoparasites of bats, which may act as vectors for the transmission of pathogens. Overall, this line of research makes an important contribution to the One Health concept.

Key findings: Two DNA viruses from the Circoviridae family (which are non-pathogenic) that were previously unknown to science were isolated from droppings collected from bats in the Kharkiv region. This study was carried out in collaboration with the virology group at the University of Pécs, Hungary.

A unique and first-of-its-kind screening in Ukraine for bacterial agents in the ectoparasites of bats, conducted by a joint team of Ukrainian and German researchers, led to the discovery of a species of rickettsia new to Europe, namely: Rickettsia parkeri.

Key publications:

Vlaschenko, A., Răileanu, C., Tauchmann, O. Muzyka, D., Bohodist, V., Filatov, S., Rodenko, O., Tovstukha I., & Silaghi, C. (2022). First data on bacteria associated with bat ectoparasites collected in Kharkiv oblast, Northeastern Ukraine. Parasites & Vectors 15, 443

Szentiványi T., Kravchenko K., Vlaschenko A., Estók P. (2018). First record of Laboulbeniales (Fungi: Ascomycota) infection on bat flies (Diptera: Nycteribiidae) from the Caucasus region. Folia Entomologica Hungarica, 79: 1-8 DOI: 10.17112/FoliaEntHung.2018.79.1

Kemenesi G., Zana B., Kurucz K., Foldes F., Urban P., Vlaschenko A., Kravchenko K., et al., Jakab F. (2017). High diversity of replication-associates protein encoding circular DNA viruses in guano samples of European bats. Archives of Virology, 163 (3): 671-678.

Kravchenko K., Vlaschenko A., Prylutsky O., Prylutska A. (2015). A Search of Geomyces destructans, a Dangerous Pathogen of Bats, in Caves of Eastern Europe. Russian Journal of Ecology. 46(5): 397-400.

6) Practices relating to the treatment, rehabilitation and care of bats in captivity.

Summary: The ‘Ukrainian Centre for the Rehabilitation of Chiroptera’ (a partner project of the Laboratory of Chiropteran Biology) operates as the leading centre for bat rehabilitation in Eastern Europe, receiving injured and sick animals from across Ukraine. Over many years of work, dozens and hundreds of individual cases of successful bat treatment have been documented. Most of these have been returned to the wild. The effects of various medicines and pharmaceutical preparations on bats have been documented. Treatment protocols for diseases and injuries have been developed. Many animals, following treatment for injuries that are incompatible with a return to the wild, remain in lifelong rehabilitation. The results obtained are very important for understanding the processes of recovery and wound healing in mammals, which have significant physiological differences. Furthermore, keeping animals in lifelong rehabilitation allows for the observation of their behavioural characteristics, which is extremely difficult to do in the wild.

Key results:

Many years of experience in the rescue, rehabilitation and treatment of bats have been set out in a practical guide to bat rehabilitation. This is the first publication of its kind in Ukraine.

Key publications:

Shulenko A., Zemliana K., Bohodist V., Yerofeieva M., Vlaschenko A. War winter, results of winter bat rehabilitation in 2022-2023 of Ukrainian Bat Rehabilitation Center. Poster on Х Ogólnopolska Studencka Konferencja Teriologiczna, Poznań, Poland, 2023.

Прилуцька А., Влащенко А., Гуков В., Доманська А. (2021): Посібник з реабілітації рукокрилих. Харків 2021, 124 p.

Prylutska A., Vlaschenko A., Kravchenko K., et al. (2017). Results of Bat Rehabilitation Center work during 2012-2017, Kharkiv, Ukraine. Abstract of XXVI Ogólnopolska Konferencja Chiropterologiczna, 17-19 November 2017, Wiezyca, Poland: 30.

7) The physiology of diurnal torpor and hibernation in chiropterans.

Abstract: Chiroptera possess unique physiological abilities to regulate their body temperature in response to environmental conditions. These abilities enable them to successfully survive both short periods of cold, rainy weather in summer and the long winters of temperate latitudes. Thanks to modern mini-sensors that measure the surface temperature of animals’ bodies, it is possible to track temperature dynamics in relation to a range of parameters. These parameters include the size of the group in which bats hibernate, the sex and age characteristics of the individuals, and their body condition. The rate of rewarming, the duration spent in a state of torpor or, conversely, euthermia, are among the parameters being investigated. This area of research is extremely interesting in terms of assessing and understanding the physiological characteristics and mechanisms by which mammals adapt to changes in their environment.

Key publications:

Moiseienko M., Vlaschenko A. (2023). Deep torpor patterns and body mass loss of above-ground hibernating bats (Nyctalus noctula) in captivity; effects of sex, age and grouping. Acta Chiropterologica. 25, (2), pp. 299-310

8) The impact of heavy metals and radioactive contamination on bats.

Abstract: Bats occupy the top of the food chain, consuming insects in quantities amounting to up to 30 per cent of a bat’s body weight. It is traditionally believed that this ecological characteristic of bats leads to the accumulation of toxic substances of various origins (heavy metals, radionuclides, organic pesticide molecules). Accordingly, assessing the levels of toxic substances in bats, the pathways through which these substances accumulate, and the mechanisms by which bats adapt to them are important areas of research with a focus on the conservation of these animals. In collaboration with several analytical laboratories in Ukraine and abroad, an assessment was carried out of the levels of radionuclides and heavy metals in various bat species and in different organs of these animals. On two occasions (in 2008 and 2018), scientific expeditions travelled to the very heart of the Chernobyl Exclusion Zone to assess the levels of caesium and strontium radionuclides in bats inhabiting the most radioactively contaminated area in Europe. Since 2019, joint research has been underway with the Laboratory of Ecotoxicology at Jagiellonian University (Poland) on the levels of heavy metals in bats found dead in various cities across Ukraine.

Key findings:

For the first time, the levels of caesium and strontium radionuclides have been assessed in bats inhabiting the radioactively contaminated Chernobyl Exclusion Zone. A comparative analysis was carried out for different species and different sex-age groups, and a general comparison was also made with animals from other systematic and trophic groups.

For the first time in Ukraine, results are presented on the levels of heavy metals in three bat species (Nyctalus noctula, Eptesicus serotinus and Pipistrellus kuhlii). A comparison was made of pathogen levels in the external tissues of bats (fur and wing membrane) as potential indicators of contamination levels in internal organs.

Key publications:

Timofieieva, O., Vlaschenko, A., & Laskowski, R. (2023). Could a city-dwelling bat (Pipistrellus kuhlii) serve as a bioindicator species for trace metals pollution?. The Science of the total environment, 857(Pt2), 159556.

Timofieieva, O., Swiergosz-Kowalewska, R., Laskowski R., Vlaschenko A. (2021). Wing membrane and Fur as indicators of metal exposure and contamination of internal tissues in bats. Environmental Pollution. 276, 116703

Gashchak S.P., Beresford N.A., Maksimenko A., Vlaschenko A.S. (2010). Strontium-90 and caesium-137 activity concentrations in bats in the Chernobyl exclusion zone. Radiation and Environmental Biophysics. 49 (4): 635-644.

9) Research in other areas.

Summary: Research into and observation of bats is also being carried out in many other areas, namely behaviour, reproductive biology, ecological role, migration and seasonal movements, craniometry and morphology.

Key findings:

Observations of animals in captivity have revealed the first documented case of non-penetrative mating in mammals. By combining observations made in Ukraine with results and observations from other countries (Switzerland, the Netherlands, Germany), an article was prepared and published in the world’s leading biology journal, *Current Biology*.

By combining the results of an experiment on feeding bats in captivity with the collection of droppings in the wild, a conversion factor was developed for the first time to estimate the weight of potentially consumed insects based on the weight of the droppings. A quantitative estimate of the potential consumption of insect biomass was developed.

Thanks to the implementation of a large-scale bat ringing programme, data were obtained on both long-distance flights (200 kilometres or more) and local movements. It has been demonstrated that Nyctalus noctula have established a resident population around Kharkiv; individuals of this species have changed their migratory status from long-distance migrants to residents, undertaking only local seasonal movements between the city and the surrounding forests.

Sexual dimorphism in the craniometric parameters of resident and migratory bat species in Ukraine has been investigated. Differences in certain parameters between females and males of resident species have been demonstrated, illustrating the mechanism of ecological niche separation between the sexes in mammals.

Key publications:

Fasel J.N., Jeucken J., Kravchenko K., Fritze M., Ruczyński I., Komar E., Moiseienko M., Shulenko A., Vlaschenko A., et al. (2023). Mating without intromission in a bat. Current Biology. 33 (22), рр. 1182-1183

Moiseienko M., Vlaschenko A. (2021). Quantitative evaluation of individual food intake by insectivorous vespertilionid bats (Chiroptera, Vespertilionidae). Biology Open. 10(6): bio058511

Vlaschenko A., Prylutska, A., Kravchenko, K., et al. (2020). Regional recapture of bats (Chiroptera, Vespertilionidae) ringed in Eastern Ukraine. Zoodiversity, 54(1): 53-66.

Holovchenko O., Kravchenko K., Vlaschenko A. (2017). Whose females are larger? Sex dimorphism in skull parameters of two air-hawking Vespertilionidae bats. Abstract of The Ninth International Zoological Congress of “Grigore Antipa” Museum, 22-25 November 2017, Bucharest, Romania: 102-103.

Gashchak S., Vlaschenko A., Estok P., et al. (2015). New long-distance recapture of a Noctule (Nyctalus noctula) from Eastern Europe. Hystrix, the Italian Journal of Mammology. 26(1): 59-60

International projects

One of the areas of our work is participation in national and international grant programmes. Since July 2023, the H.S. Skovoroda Kharkiv National Pedagogical University has been involved in the international consortium for the HORIZON 2020 project, OneBat (2023–2025), which is dedicated to studying the distribution and movement of bats and the pathogens they carry. Accordingly, A. Vlaschenko is the project coordinator and participant. The project is registered with UkrINTEI as an International Technical Project under number 185/81 dated 24 January 2024.

A. Vlaschenko is one of 124 researchers from Ukraine whose research projects have been selected for funding under the Marie Skłodowska-Curie programme for researchers from Ukraine (MSCA4Ukraine), which is funded by the European Union. The research project ‘Moving over the frontier: habitat and climate drivers of bat population abundances and bat assemblages across the East European Plain’ (Moving over the frontier: habitat and climate drivers of bat population abundances and bat assemblages across the East European Plain) was carried out as part of the fellowship at the Leibniz Institute for Zoo and Wildlife Research, located in Berlin, Germany.

Key publication (2023)

Vlaschenko, A., Rodenko, O., Hukov, V., et al. (2023). Do Bats Avoid the Urban Core in the Breeding Season? A Case Study from Temperate Latitudes. Diversity. 15, 967.