Martes Foina Research Articles

Investigations on the Potential Role of Free-Ranging Wildlife as a Reservoir of SARS-CoV-2 in Switzerland.

Amid the SARS-CoV-2 pandemic, concerns surfaced regarding the spread of the virus to wildlife. Switzerland lacked data concerning the exposure of free-ranging animals to SARS-CoV-2 during this period. This study aimed to investigate the potential exposure of Swiss free-ranging wildlife to SARS-CoV-2. From 2020 to 2023, opportunistically collected samples from 712 shot or found dead wild mustelids (64 European stone and pine martens, 13 European badgers, 10 European polecats), canids (449 red foxes, 41 gray wolves, one golden jackal) and felids (56 Eurasian lynx, 18 European wildcats), as well as from 45 captured animals (39 Eurasian lynx, 6 European wildcats) were tested. A multi-step serological approach detecting antibodies to the spike protein receptor binding domain (RBD) and N-terminal S1 subunit followed by surrogate virus neutralization (sVNT) and pseudotype-based virus neutralization assays against different SARS-CoV-2 variants was performed. Additionally, viral RNA loads were quantified in lung tissues and in oronasal, oropharyngeal, and rectal swabs by reverse transcription polymerase chain reactions (RT-qPCRs). Serologically, SARS-CoV-2 exposure was confirmed in 14 free-ranging Swiss red foxes (prevalence 3.1%, 95% CI: 1.9-5.2%), two Eurasian lynx (2.2%, 95% CI: 0.6-7.7%), and one European wildcat (4.2%, 95% CI: 0.2-20.2%). Two positive foxes exhibited neutralization activity against the BA.2 and BA.1 Omicron variants. No active infection (viral RNA) was detected in any animal tested. This is the first report of SARS-CoV-2 antibodies in free-ranging red foxes, Eurasian lynx, and European wildcats worldwide. It confirms the spread of SARS-CoV-2 to free-ranging wildlife in Switzerland but does not provide evidence of reservoir formation. Our results underscore the susceptibility of wildlife populations to SARS-CoV-2 and the importance of understanding diseases in a One Health Concept.

Disentangling ground-nest predation rates through an artificial nests experiment in an area with western capercaillie (Tetrao urogallus) presence: martens are the key

The western capercaillie (Tetrao urogallus) is a species of conservation concern that has been experiencing a severe decline in many regions of Europe. The poor breeding success rather than mortality of full-grown birds has been suggested to be responsible for its decline, been the nest loss a potential driver of the low productivity (number of chicks per female and year) of capercaillie. Working in a capercaillie population in the Pyrenees, we aimed to provide further insights into nest predation by monitoring 82 artificial nests (58 of them with camera traps), and estimating the population density of predators using camera traps and applying random encounter model and camera trap distance sampling. Pine/stone martens -Martes foina, Martes martes- were the species with higher nest predation rates (23%) despite being the less abundant (0.49 ind/km2), followed by foxes -Vulpes vulpes- (11%) and a population density of 3.37 ind/km2, and wild boar -Sus scrofa- (4%) and 6.95 ind·km− 2; predators could not be identified at 27% of the events. After fitting statistical models on the nest predation data, we observed that the martens’ encounter rate (i.e. number of martens detected per camera and day) and the altitude had a positive significant effect on the artificial nest predation probability. While caution is recommended in artificial nest experiments, our results are valuable highlighting the importance of martens and red foxes when addressing nest predation to promote the breeding success and population recovery of western capercaillie populations.

Estimation of mammalian wildlife density by REM method in a Mediterranean forest ecosystem (Pinus brutia) of Türkiye: how human footprint effects mammal community?

BackgroundDetermining the density of mammalian wildlife in an ecosystem is very important for the ecosystem conservation. The aim of this study is to reveal mammalian wildlife density and compare the effect human footprint index (HFI) on the Mediterranean ecosystems. The mammalian wildlife surveys were conducted between August 2013 and December 2013, using 21 camera traps with 2175 camera trap days in a Mediterranean forest ecosystem in İzmir, Türkiye. We used random encounter model (REM) method to estimate densities.ResultsThe population density for 5 mammals were; for red fox 7.89 ind./km2 (± 0.82 SE), wild boar 4.36 ind./km2 (± 0.46 SE), European hare 15.33 ind./km2 (± 03.37 SE), beech marten 0.99 ind./km2 (± 0.10 SE) and golden jackal 0.50 ind./km2 (± 0.05 SE). These results were compared with mammal community which was previously studied in another Mediterranean ecosystem in Muğla, Türkiye, includes caracal and has a lower human footprint index.ConclusionsAccording to results of this study human activity which can be revealed by Human footprint index (HFI) is one of the main parameter on Mediterranean ecosystem and it is effecting the density and occurence of species in mammal community. Both a higher human footprint index and the absence of caracal might cause higher density of red fox and European hare in İzmir, Türkiye. This study also suggests that caracal might be a serious suppressor on red fox which could be explained by competition. Caracal may also control the European hare in Mediterranean forest ecosystem of Anatolia. Thus, decreasing human footprint index and maintaining caracal suppressor effect are crucial for the conservation of the whole Mediterranean ecosystem.

Spatial distribution pattern of mustelids in the eastern edge of the Qinghai-Tibet Plateau.

Evolutionary theory predicts that the species of an evolutionarily successful taxon would not overlap in spatial distribution. To test the prediction, we document our research on the spatial associations of mustelids, an evolutionarily successful group of order Carnivore, using infrared camera trap data on species distribution collected from the national nature reserves (NNRs) of Liancheng, Wolong, Tangjiahe and Heizhugou in China in 2017-2021. Data showed seven mustelid species occurring in the study area, including Arctonyx collaris, Meles leucurus, Martes foina, Martes flavigula, Mustela altaica, Mustela nivalis and Mustela sibirica. Following Ricklef's definition of biological community, we identified five networks of species associations. The mustelids occurred in the networks. Species from the same genus, such as M. foina and M. flavigula, stayed in different networks to avoid competition owing to similar feeding habits or habitat preferences. Species with different feeding habits or habitat preferences either occurred in different networks, such as M. altaica and M. flavigula, or coexisted in the same networks but avoided direct spatial associations, such as M. foina and A. collaris. Asymmetrical associations were found between different genera, such as M. foina and M. altaica, or between different subfamilies, such as M. flavigula and A. collaris. These associations may be attributed to interspecific killing or seed dispersal. However, these associations accounted for only a small proportion and would not impact the species diversity of Mustelidae. It is thus concluded that the prediction is supported by our research findings and that spatial avoidance may be the biogeographic strategy of maintaining the species diversity of the family. We also found that the well protection of the mustelids may benefit the overall biodiversity conservation in Heizhugou, an NNR that has experienced severe deforestation.

An integrated assessment of niche partitioning reveals mechanisms of coexistence between mesocarnivores

Species diversity depends on the capacity of species to coexist, and when these share similar ecological requirements some degree of partitioning of the ecological niche is expected. Within the order Carnivora, direct and indirect interspecific interactions shape community structure and composition. Although strong negative interactions (e.g., interspecific killing) are expected between large carnivores and subordinate species, mesocarnivores that dominate most human disturbed landscapes can still strongly compete for resources given their similar body size and energy requirements. To identify the mechanisms of coexistence between mesocarnivore species in a Mediterranean landscape we assessed the ecological niche overlap between five species (Vulpes vulpes, Meles meles, Martes foina, Herpestes ichneumon, Genetta genetta), by simultaneously measuring the space, time, and trophic resource use. The multi-species occupancy model fit to camera-trapping data revealed spatial co-occurrence between most species’ pairs and an avoidance pattern between only stone marten and Eurasian badger (78 % probability of a negative effect). Using genetically identified scats, we assessed trophic niche breadth and overlap. Niche breadth was narrow for red fox, Eurasian badger, and stone marten, given these species consumed almost exclusively fruits and arthropods, and so trophic niche overlap was high. For the genet and the mongoose, the consumption of different food resources (e.g., mammals, birds, and reptiles) increased niche breadth and decreased the niche overlap with the other sympatric species. Finally, niche segregation was more significant along the temporal axis, since the mongoose has a diurnal activity pattern and the remaining carnivore species, although mostly nocturnal, had small asynchronies in the activity peaks which could decrease the chance of direct encounters. Therefore, our results suggest that similar habitat preferences and ecological requirements rather than interspecific competition shape the mesocarnivores’ resource use in this landscape. Nonetheless, fine-scale temporal segregation seems the main mechanism to facilitate coexistence, together with small differences in trophic resource use, especially for species with high spatial and temporal overlap.

The frequent five: Insights from interviews with urban wildlife professionals in Germany

Abstract Wildlife in cities divides people, with some animals bringing positive benefits and others causing conflict, for example due to property damage. Urban wildlife professionals from municipal administration, nature conservation, and hunting associations have a crucial role in shaping human‐wildlife relationships in cities and fostering conflict‐free coexistence. While many studies on urban wildlife have focused on the views of citizens, few have investigated the perspectives of experts to date. To address this knowledge gap, we interviewed 36 urban wildlife professionals giving guidance in the context of urban wildlife management, either in one of the four largest German cities by population (Berlin, Hamburg, Munich and Cologne) or at the national level. Red foxes, wild boars, raccoons, stone martens and Eurasian beavers were the five mammal species most frequently highlighted in interviews to cause human‐wildlife conflicts. The interviewees saw wild boars and raccoons as the most controversial urban wild mammals but emphasized the need to create refuges for beavers and better inform the public about foxes. Management in terms of public outreach, urban planning and population control, as well as establishing official contact points and stricter fines of activities violating regulations were highlighted as important elements of a toolkit to manage urban wildlife conflicts. Read the free Plain Language Summary for this article on the Journal blog.

Electrocutions as an important cause of mortality for a mesocarnivore

Abstract In this work, we have analysed the different causes of admissions of stone martens (Martes foina), genets (Genetta genetta) and pine martens (Martes martes) in two rehabilitation centres in Castilla y León (Spain) during 32 years (1991–2022). The results indicate that the most important factor for stone martens was road kills with 227 martens (53.4 %) followed by electrocutions with 90 martens (21.2 %). From genets, 94 of them (68.6 %) were due to roadkill and 7 (5.1 %) were due to electrocution. The most important cause of admission for pine martens was road kills with 22 (88 %) and 1 (4 %) due to electrocution. Possible explanations for the observed high mortality of stone martens in electric pylons are discussed.

Eurasian red squirrels (Sciurus vulgaris) and mesocarnivores in a Mongolian protected area

Abstract Prey-predator interactions across time and space strongly influence many animal communities. This study unveils the first insights into the ecology of the Eurasian red squirrel (Sciurus vulgaris) in Mongolia, and specifically in Bogd Khan Mountain Strictly Protected Area. We used by-catch data obtained from camera traps to analyze activity patterns and potential interactions with mammalian predators. Red squirrels exhibited primarily diurnal activity with occasional nocturnal forays, while potential predators like foxes (Vulpes vulpes, Vulpes corsac) and martens (Martes foina, Martes zibellina) displayed cathemeral and nocturnal patterns, respectively. The diurnal Pallas’s cat (Otocolobus manul) showed the greatest activity overlap with squirrels. Suggesting predator avoidance behavior potentially mediated by olfactory cues, squirrel activity was negatively impacted by marten presence, which was in turn potentially affected by human disturbance. We highlight the need for further investigations, particularly regarding the dietary composition of Pallas’s cats in forested habitats and the broader ecological implications of human disturbance on predator–prey dynamics within this crucial conservation area.

A Canine Distemper Outbreak in Urban Red Foxes (Vulpes vulpes) in Brussels, Belgium, 2020.

Canine distemper has been observed infrequently in Belgian wildlife, mainly stone martens (Martes foina) and red foxes (Vulpes vulpes). This report describes an outbreak in the Brussels urban red fox population, characterized by its high density. The identified virus matched those within a cluster of viruses found previously in red foxes in Germany. Different canine distemper virus (CDV) strains, found in Belgian wild carnivores, share relationships with viruses found farther east. This and other reports indicate an endemic distribution of CDV in wild carnivores in Europe whereby the complex interplay of population density, group immunity, and infection of metapopulations determines the pattern of spatiotemporally alternating outbreaks.

First photo evidence of stone marten Martes foina (Erxleben, 1777) in Rolwaling and Lapchi valleys of Gaurishankar Conservation Area, Nepal

Stone marten (Martes foina) is a fascinating, elusive and crepuscular small carnivore mammal belonging to the family Mustelidae. They are widely distributed throughout Europe and in western and central Asia. Little information is available on the distribution pattern and habitat requirement of the species in the Nepal Himalaya. Based on the camera trap study, we reported the first photo evidence of the presence of stone marten in the Lapchi and Rolwaling valleys of the Gaurishankar Conservation Area. This finding has opened new avenues for further ecological research and to investigate human-induced threats to the species in the region.

Chromatic Restoration of a Beech Marten Taxidermy Specimen to Resemble its Original Population: Analysing Painting Products and Colour Parameters

ABSTRACT Natural history collections preserve invaluable taxidermy specimens, which are prone to light-induced degradation, compromising their historical and educational significance. Restoration of these specimens to their original appearance through chromatic reintegration is imperative. The principle of reversibility mandates interventions that are modifiable or reversible without harming the original work, thereby preserving authenticity and enabling future conservation efforts. This study aims to identify the most suitable product for chromatic reintegration of a mammal taxidermy specimen, evaluate its fidelity to the original population, and assess its imperceptibility to the general public during exhibitions. Various products underwent rigorous evaluation for colouration, drying time, coverage, reversibility, safety, and resistance to light degradation. Accelerated aging tests using the Xenotest were conducted to simulate long-term light exposure. A beech marten taxidermy specimen was restored with the chosen dye, and its colour was compared against skins from the original population of the species. Public perception tests were conducted to gauge the ability of people to detect the chromatic restoration during exhibitions. Orasol® dye emerged as the optimal choice for chromatic reintegration, meeting criteria for colouration, reversibility, coverage, and resistance to light degradation. Despite its toxicity for aquatic organisms, it demonstrated promising results. Most colour measurements closely matched the original beech marten population, with minor hue deviations. Public perception tests confirmed the imperceptibility of the chromatic restoration, indicating its suitability for exhibition and educational purposes. This study highlights the importance of authenticity and imperceptibility in restoration processes, emphasizing the need for meticulous consideration of budget constraints in museum settings.

WILDbase: towards a common database to improve wildlife disease surveillance in Europe.

BackgroundTo be better prepared for emerging wildlife-borne zoonoses, we need to strengthen wildlife disease surveillance.AimThe aim of this study was to create a topical overview of zoonotic pathogens in wildlife species to identify knowledge gaps and opportunities for improvement of wildlife disease surveillance.MethodsWe created a database, which is based on a systematic literature review in Embase focused on zoonotic pathogens in 10 common urban wildlife mammals in Europe, namely brown rats, house mice, wood mice, common voles, red squirrels, European rabbits, European hedgehogs, European moles, stone martens and red foxes. In total, we retrieved 6,305 unique articles of which 882 were included.ResultsIn total, 186 zoonotic pathogen species were described, including 90 bacteria, 42 helminths, 19 protozoa, 22 viruses and 15 fungi. Most of these pathogens were only studied in one single animal species. Even considering that some pathogens are relatively species-specific, many European countries have no (accessible) data on zoonotic pathogens in these relevant animal species. We used the Netherlands as an example to show how this database can be used by other countries to identify wildlife disease surveillance gaps on a national level. Only 4% of all potential host-pathogen combinations have been studied in the Netherlands.ConclusionsThis database comprises a comprehensive overview that can guide future research on wildlife-borne zoonotic diseases both on a European and national scale. Sharing and expanding this database provides a solid starting point for future European-wide collaborations to improve wildlife disease surveillance.

Is the Iberian lynx a hunters’ ally? a case study from a reintroduced population in Portugal

The Iberian lynx (Lynx pardinus) is one of the most endangered felids in the world, and a high proportion of its populations occur in hunting grounds managed for red-legged partridge (Alectoris rufa) and wild rabbit (Oryctolagus cuniculus), both game species of high socio-economic value and the latter a key prey species for the lynx. In this case study from south-eastern Portugal, we evaluated the game management practices, the abundance of partridges and rabbits (expressed as Kilometric Abundance Index), and the occurrence of mesocarnivores in four hunting grounds, two with and two without breeding lynx. In all grounds game management was conducted but in those where lynx occurred, full-time gamekeepers were employed and hunting was the major source of income. The results showed that grounds with breeding lynx had higher KAI values for partridges and rabbits, together with reduced mesocarnivores occurrence (particularly red fox Vulpes vulpes and stone marten Martes foina), compared to those without breeding lynx. Our results confirm that lynx occurrence fits within the management traits of those hunting grounds in Iberia aiming to increase partridges and rabbits for sustainable hunting, as they act as ‘natural’ gamekeepers. This could be considered as a ‘win-win’ situation; successful for lynx’s establishment and small game conservation.

Unimodal activity pattern of stone marten in a Mediterranean island habitat

Unimodal activity pattern of stone marten in a Mediterranean island habitat

Apex predators can structure ecosystems through trophic cascades: Linking the frugivorous behaviour and seed dispersal patterns of mesocarnivores

Abstract Current global change scenarios demand knowledge on how anthropogenic impacts affect ecosystem functioning through changes in food web structure. Frugivorous mesocarnivores are a key link in trophic cascades because, while their abundance and behaviour are usually controlled by apex predators, they can provide high‐quality seed‐dispersal services to plant communities. Thus, the recent rewilding of large carnivores worldwide can trigger cascading effects for plants. We investigated the top‐down effects of an apex predator (Iberian lynx Lynx pardinus) on seed‐dispersal services mediated by two mesocarnivore species (red fox Vulpes vulpes and stone marten Martes foina) at the plant community level by comparing areas with and without lynx in a Mediterranean mountain range in Southern Spain. We collected scats of mesocarnivores (n = 1575) to assess frugivory and seed dispersal of 15 plant species over two consecutive fruiting seasons and two habitat types (open and forest). Specifically, we assessed the effect of lynx presence on (i) seed occurrence and fleshy‐fruit biomass per scat, (ii) number of scats containing seeds and (iii) diversity of dispersed seeds. The quantity and diversity of dispersed seeds drastically decreased under predation risk for both mesocarnivore's species. Seed dispersal by stone martens was negatively affected by the presence of lynx, with a marked reduction in the number of scats with seeds (93%) and the diversity of dispersed seeds (46%). Foxes dispersed 68% fewer seeds in open habitats when coexisting with lynx, probably leading to differential contributions to seed‐dispersal effectiveness among habitats. Our study reveals a novel trophic cascade from apex predators to plant communities. The behavioural responses of frugivorous mesocarnivores to predation risk and the reduction in the intensity of their faecal deposition pattern are probably related to their lower abundance when co‐occurring with apex predators. While rewilding apex predators is a successful conservation tool, attention should be paid to cascading effects across food webs, particularly where frugivore megafauna is missing and mesocarnivores provide unique services to plants. Read the free Plain Language Summary for this article on the Journal blog.

Following urban predators – long‐term snow‐tracking data reveal changes in their abundance and habitat use

AbstractUrban habitats differ from natural environments, however some predatory species have become established in cities across the globe. The aim of our study was to compare the occurrence of the red fox and the stone marten in Warsaw during three time periods (1976–1978, 2005–2008, 2015–2021) and in different habitats. Generalized linear models were used to show factors affecting the density indices of these two species (i.e., frequency of occurrence of tracks of each species recorded during snow tracking on linear transects). The frequency of occurrence of tracks of these two species on transects increased over time and was explained by habitat type and distance from the city centre. The frequency of fox tracks was higher in more‐natural habitats located far from the city centre. In the first period (1976–1978), this species was recorded only in forests and riparian areas. In the last period (2015–2021), its tracks were recorded frequently in built‐up areas and cemeteries. From the beginning of the first period, the stone marten was recorded in a wider range of habitats than the fox and it colonized all habitat types in the subsequent periods, but a statistically significant increase was observed only for cemeteries. The frequency of occurrence of stone marten tracks was lower than that of red fox tracks in most natural and seminatural habitats (forests, parks, riparian areas). No relationship between the occurrence of the red fox and the stone marten was found. We speculate that the growth of the urban red fox numbers was driven by an increase in the national population as a result of anti‐rabies vaccinations. In turn, the stone marten, being a synanthropic species, was present in the city centre from the beginning of the study, but it now occurs in a wider range of habitats.

Fleas of wild carnivores in Romania: diversity, distribution, and host-associations

BackgroundFleas are important hematophagous insects, infesting mammals and birds with a worldwide distribution. Fleas of medical importance have been reported from various carnivores worldwide, such as felids, canids, or mustelids. Romania hosts a wide carnivore diversity, but very little is known about flea species that parasitize these animals in Romania. This study aimed to provide a better understanding of the fleas’ diversity and their distribution in a relatively large and diverse number of wild carnivore hosts from Romania.MethodsFrom 2013 to 2021, 282 carcasses of wild carnivores from different locations in Romania were collected and examined for the presence of ectoparasites. All collected fleas were morphologically identified using specific keys and descriptions. An analysis of the co-occurrence networks was performed.ResultsA total of 11 flea species were identified: Pulex irritans (41.09%), Paraceras melis (20.11%), Ctenocephalides felis (7.33%), Ctenocephalides canis (7.83%), Monopsyllus sciurorum (11.11%), Chaetopsylla trichosa (21.96%), Chaetopsylla homoea (5.5%), Chaetopsylla tuberculaticeps (100%), Chaetopsylla rothschildi (13.33%), Chaetopsylla sp. (14.34%), Chaetopsylla globiceps (5.12%), Echidnophaga gallinacea (10%). The statistical analyses showed a significant difference between the infestation of Martes foina with females being more frequently infected than males (66% versus 33%). Paraceras melis infesting Meles meles had a significantly higher prevalence in female badgers than in males (× 2 = 7.7977, P < 0.01) and higher intensities of infestations in males than in females (t = 1.871, P < 0.05).ConclusionsThis is the first large-scale study investigating the distribution and diversity of flea species infesting wild carnivores in Romania. Three flea species were identified for the first time in Romania (E. gallinacea, C. homoea, and C. tuberculaticeps).Graphical

Wildfires affect mesocarnivores habitat use and mammalian predator-prey relationships in a Mediterranean ecosystem

Effects of fires on carnivores are still poorly understood, particularly in the fire-prone Mediterranean basin. For instance, whether the effects are mainly mediated by prey abundance (Prey Abundance Hypothesis, PAH), prey catchability (Prey Catchability Hypothesis, PCH) or habitat suitability is unclear. Our objective was to investigate the role of fire, mammalian prey abundance, habitat suitability and their interactions in shaping the use of space and time of two carnivores, i.e., the red fox Vulpes vulpes and the stone marten Martes foina. The study area was Monte Pisano (Italy), where 12 km2 of surface burned in 2018. In early summer 2021 a stratified random sampling design was implemented, with fire and forest type as main strata. Fifty sites were selected, and two infrared cameras were placed at each site. Camera data were used to develop single-species occupancy models for the two predators, whereas time overlap between theme and their prey was evaluated through the Mardia-Watson-Wheeler test. Fox occupancy decreased with increasing herbaceous cover, but only when “mouse and voles” abundance was medium to high, regardless of habitat type. Fox also had significant differences in temporal activity between burnt and unburnt areas, not coupled by a similar pattern for its prey. In contrast, stone marten occupancy mainly depended on canopy cover. The fox could have adapted its hunting strategy to features of the environment and prey abundance, somehow supporting both PCH and PAH. In time, this species could optimize its activity in burnt and unburnt areas according to the brightness of the night. Differences in activity in “mice and voles” were interpreted as anti-predatory responses to the fox. Lastly, the stone marten did not pursue its prey in open areas. In conclusion, carnivores’ habitat use and mammalian predator-prey relationships were overall influenced by fire and post-fire successions.

Nosopsyllus (Nosopsyllus) spiniformis n. sp., a new ceratophyllid flea (Siphonaptera, Ceratophyllidae, Ceratophyllinae) from Trkiye.

A new ceratophyllid flea species, Nosopsyllus (Nosopsyllus) spiniformis n. sp., is described and illustrated. Specimens were collected from Gnthers vole, Microtus guentheri (Danford & Alston), Schidlovskys vole, Microtus schidlovskii Argyropulo, in Adana province, and stone marten, Martes foina (Erxleben), in Tokat province. With the new species, the number of Nosopsyllus taxa known from Trkiye now tallies 11 (six species and five subspecies).

Чужорідні види ссавців району природного заповідника «Дніпровсько-Орільський»

The paper provides information on alien mammal species occurring in the territory of the Dnipro–Oril Nature Reserve. The data were collected during annual mammal surveys and by compiling the data provided in the Chronicles of Nature of previous years (1991–2022) within the framework of the scientific topic ‘Study of biodiver-sity, structure and dynamics of natural complexes of the Dnipro–Oril Nature Re-serve.’ Since the creation of the reserve, 44 species of mammals belonging to six orders (Leporiformes, Muriformes, Soriciformes, Vespertilioniformes, Caniformes, and Cerviformes) have been recorded in its territory. The species diversity of mammals of the reserve corresponds to 71% of the mammal fauna of Dniprope-trovsk Oblast and 34% of the mammal fauna of Ukraine. Most of the mammal species found in the reserve are indigenous but the raccoon dog Nyctereutes procy-onoides, muskrat Ondatra zibethicus, and sika deer Cervus nippon, which are arti-ficially introduced species. In addition, the brown rat Rattus norvegicus and the house mouse Mus musculus are distant invaders. The beech marten Martes foina, Blyth’s pipistrelle Pipistrellus lepidus, and serotine bat Eptesicus serotinus are close invaders. Alien species make up 18% of the mammal fauna of the reserve, being represented by a total of eight species. However, there are also species with fluctuating ranges in the studied area: European roe deer Capreolus capreolus, elk Alces alces, Eurasian otter Lutra lutra, Eurasian badger Meles meles, and wild boar Sus scrofa. The periodic contraction and expansion of their ranges within the region makes them similar to introduced species. The presence of the majority of adventive species was registered during the first inventory of the fauna of the described territory during the establishment of the reserve in 1991. However, the first sighting of serotine bat occurred in March 2013 in the floodplain part of the reserve, and the sighting of Blyth’s pipistrelle in the reserve was recorded in the spring of 2016. The article describes the specifics of the existence of alien mammal species in the reserve. The dynamics of abundance, population structure, diet, and environmental impact are presented. Other adventive species that could possibly be found in this territory in the near future are the American mink Neogale vison and golden jackal Canis aureus. A case of visual observation of the coypu Myocastor coypus in the vicinity of the reserve is also presented.