Countrywide screening supports model-based predictions of the distribution of Batrachochytrium dendrobatidis in Ukraine.

The chytrid Batrachochytrium dendrobatidis (Bd) is a widespread fungus causing amphibian declines across the globe. Although data on Bd occurrence in Eastern Europe are scarce, a recent species distribution model (SDM) for Bd reported that western and north-western parts of Ukraine are highly suitable to the pathogen. We verified the SDM-predicted range of Bd in Ukraine by sampling amphibians across the country and screening for Bd using qPCR. A total of 446 amphibian samples (tissue and skin swabs) from 11 species were collected from 36 localities. We obtained qPCR-positive results for 33 samples including waterfrogs (Pelophylax esculentus complex) and fire- and yellow-bellied toads (Bombina spp.) from 8 localities. We found that Bd-positive localities had significantly higher predicted Bd habitat suitability than sites that were pathogen-free. Amplification and sequencing of the internal transcribed spacer (ITS) region of samples with the highest Bd load revealed matches with ITS haplotypes of the globally distributed BdGPL strain, and a single case of the BdASIA-2/BdBRAZIL haplotype. We found that Bd was non-randomly distributed across Ukraine, with infections present in the western and north-central forested peripheries of the country with a relatively cool, moist climate. On the other hand, our results suggest that Bd is absent or present in low abundance in the more continental central, southern and eastern regions of Ukraine, corroborating the model-predicted distribution of chytrid fungus. These areas could potentially serve as climatic refugia for Bd-susceptible amphibian hosts.

Helminths found in common species of the herpetofauna in Ukraine.

Background: Only a few comprehensive studies have been carried out on parasites in amphibians and reptiles in Ukraine. This has resulted in identifying over 100 helminth species across these vertebrate groups. However, most of the studies were performed in the 20th century and the taxonomy of many parasites and their hosts has changed ever since, in addition to the discovery of new species and registrations of species that had not been previously known for Ukraine. In recent decades, there have been very few publications on helminths from amphibian or reptile hosts in this region. Notably, just one of these recent studies is a faunistic study, providing a list of helminths found in two species of green frogs - Pelophylaxridibundus (Pallas, 1771) and Pelophylaxesculentus (Linnaeus, 1758). Therefore, it is clear that publishing datasets of modern records of helminths in these vertebrate groups, based on modern taxonomy, is an essential step in further studies of their parasitic diversity. Additionally, such study is important in terms of global climate change, the growing number of possibilities of invasion of alien species (both hosts and parasites) that might potentially become a threat to native biota and growing anthropogenic pressure on local populations of hosts that affect the parasites as well. In future, this study is planned to be used for the creation of a checklist of helminths of the herpetofauna of Ukraine. The present dataset is an inventory of various species of helminths parasitising common species of the herpetofauna in central, northern, western and southern Ukraine recorded during field studies in the 2021-2023 period. New information: The dataset is the first one to represent the up-to-date and unified data on helminths of reptiles and amphibians of Ukraine. Previously, records of this group of organisms with reference to their hosts were presented as several separate records within the country. Currently, this is the largest dataset presenting geocoded records of non-human-related helminths in the fauna of Ukraine. It reports helminth species from 15 hosts (205 individuals), including eight amphibians and seven reptilian species found in various Ukrainian regions. A total of 47 helminth species have been documented in the research and during 2021-2023 period on the territory of northern (Kyiv and Zhytomyr), western (Lviv, Zakarpattia Ivano-Frankivsk), central (Vinnytsia, Dnipropetrovsk, Cherkasy, Zaporizhzhia and Poltava) and southern (Odesa) regions of Ukraine. The identified helminth species belong to the following phyla: Acanthocephala (Centrorhynchidae (2), Echinorhynchidae (2)); Nematoda (Acuariidae, Anisakidae, Cosmocercidae (3), Dioctophymatidae, Gnathostomatidae (1), Kathlanidae (1), Molineidae (7), Onchocercidae (1), Pharyngodonidae (1), Rhabdiasidae (6), Strongyloididae); Platyhelminthes (Diplodiscidae (1), Diplostomidae (2), Encyclometridae (1), Haematoloechidae (1), Leptophallidae (2), Macroderidae (1), Mesocestoididae, Opisthorchiidae (2), Plagiorchiidae (3), Pleurogenidae (2), Polystomatidae (3), Proteocephalidae (1), Strigeidae (1) and Telorchiidae (3)). Only some helminths in the dataset were not identified to species level. Material is stored in the collection of the department of Parasitology of the I. I. Schmalhausen Institute of Zoology NAS of Ukraine.

Present and future distribution of the European pond turtle versus seven exotic freshwater turtles, with a focus on Eastern Europe.

Freshwater turtles are often used as terrarium pets, especially juveniles of exotic species. At the adult stage they are often released by their owners into the wild despite their high invasion potential. In Europe these thermophilic potentially invasive alien species occupy the habitats of the native European pond turtle Emys orbicularis (Linnaeus, 1758), with new records from the wild being made specifically in Eastern Europe (Latvia and Ukraine) during recent decades. Assessing the potential of alien freshwater turtles to establish in new territories is of great concern for preventing invasion risks while preserving native biodiversity in the present context of climate change. We explored this issue by identifying the present and future (by 2050) suitable habitats of the European pond turtle and several potentially invasive alien species of freshwater turtle already settled in Europe, using a geographic information system (GIS) modelling approach based on datasets from CliMond for climate, Near-global environmental information (NGEI) for freshwater ecosystems (EarthEnv) and Maxent modelling using open-access databases, data from the literature and original field data. Modelling was performed for seven species of alien freshwater turtles occurring from the extreme northern to southern borders of the European range of E. orbicularis: the pond slider Trachemys scripta (Thunberg and Schoepff, 1792), the river cooter Pseudemys concinna (Le Conte, 1830), the Florida red-bellied cooter Pseudemys nelsoni (Carr, 1938), the false map turtle Graptemys pseudogeographica (Gray, 1831), the Chinese softshell turtle Pelodiscus sinensis (Wiegmann, 1835), the Caspian turtle Mauremys caspica (Gmelin, 1774) and the Balkan terrapin Mauremys rivulata (Valenciennes, 1833). In Ukraine, the most Eastern limit of E. orbicularis distribution, were previously reported northern American originated T. scripta, M. rivulata, M. caspica, whereas in Latvia, Emys' most northern limit, were additionally reported P. concinna, P. nelsoni, G. pseudogeographica and Asia originated P. sinensis. The resulting Species Distribution Models (SDM) were of excellent performance (AUC > 0.8). Of these alien species, the most potentially successful in terms of range expansion throughout Europe were T. scripta (34.3% of potential range expansion), G. pseudogeographica (24.1%), and M. caspica (8.9%) and M. rivulata (4.3%) mainly in Eastern Europe, especially in the south of Ukraine (Odesa, Kherson, Zaporizhzhia regions, and Crimean Peninsula). Correlation between the built SDMs for the native E. orbicularis and the invasive alien T. scripta was reliably high, confirming the highly likely competition between these two species in places they cooccur. Moreover, a Multiple Regression Analysis revealed that by 2050, in most of Europe (from the western countries to Ukraine), the territory overlap between E. orbicularis and potentially invasive alien species of freshwater turtles will increase by 1.2 times, confirming higher competition in the future. Importantly, by 2050, Eastern Europe and Ukraine are predicted to be the areas with most suitable habitats for the European pond turtle yet with most limited overlap with the invasive alien species. We conclude that Eastern Europe and Ukraine are the most relevant priority conservation areas for the European pond turtle where it is now necessary to take protective measures to ensure safe habitat for this native species on the long-term.

Spiders (Araneae) of the northeast of the Luhansk Oblast (Ukraine).

Background: The dataset contains records of spiders collected in the northeast of Luhansk Oblast in the periods 1982-1989, 2009-2011 and 2021. It aimed at the inventory of spider fauna of the Striltsivskyi Steppe Nature Reserve and species distribution in the main grassland and forest habitats of the region. The research was also concerned with the impact of conservation management ‒ hay mowing or strict protection and man-induced steppe fire on spider communities. New information: The dataset includes records from seven geographical localities in the northeast of Luhansk Oblast with 1,955 occurrences of 6662 individuals. For the first time, it provides detailed information about spider species composition, phenology and habitat distiribution within the study area, including two conservation areas and the primary material on the studies on the impact of hay making and steppe fire on spider communities. All the records of 246 spider species with georeferencing were published in GBIF.

Records of common species of amphibians and reptiles widespread in northern, central, western and southern Ukraine.

Background: The dataset includes records of amphibian and reptile species from northern, central, western and southern Ukraine made by Ukrainian herpetologist O. D. Nekrasova during her field trips in the period from 1996 to 2022. Chosen species were not included in the latest published edition of the Red Data Book of Ukraine (2009) and in the latest lists of such species prepared in 2019. The species mentioned in this dataset are characterised by wide range within the country, covering more than 70% of its territory according to spatial distribution modelling (GIS-modelling) made with the help of Maxent software. New information: The dataset highlights records of eight common species of herpetofauna of Ukraine collected by the first author for the last 26 years. Within the period from 1996 to 2022, O. D. Nekrasova collected and studied information and material on the herpetofauna of the northern, central, western and southern parts of Ukraine from a total of 3960 cadastral points (1707 - for three species of reptiles and 2253 - for five species of amphibians). These records, being now available for the international scientific community, will fill the gap in updated records of the mentioned species, being potentially useful for GIS-modelling, distribution modelling, clarification of conservation lists of national and local importance, further assessment of impact of the war on native biota etc.

Modeling the Distribution of the Chytrid Fungus Batrachochytrium dendrobatidis with Special Reference to Ukraine.

Amphibians are the most threatened group of vertebrates. While habitat loss poses the greatest threat to amphibians, a spreading fungal disease caused by Batrachochytrium dendrobatidis Longcore, Pessier & D.K. Nichols 1999 (Bd) is seriously affecting an increasing number of species. Although Bd is widely prevalent, there are identifiable heterogeneities in the pathogen's distribution that are linked to environmental parameters. Our objective was to identify conditions that affect the geographic distribution of this pathogen using species distribution models (SDMs) with a special focus on Eastern Europe. SDMs can help identify hotspots for future outbreaks of Bd but perhaps more importantly identify locations that may be environmental refuges ("coldspots") from infection. In general, climate is considered a major factor driving amphibian disease dynamics, but temperature in particular has received increased attention. Here, 42 environmental raster layers containing data on climate, soil, and human impact were used. The mean annual temperature range (or 'continentality') was found to have the strongest constraint on the geographic distribution of this pathogen. The modeling allowed to distinguish presumable locations that may be environmental refuges from infection and set up a framework to guide future search (sampling) of chytridiomycosis in Eastern Europe.

Vascular plants of old cemeteries in the Lower Dnipro region (Southern Ukraine).

Background: The dataset contains the records of vascular plant species occurrences and distribution in old cemeteries (OC) of the Lower Dnipro region (Southern Ukraine). The analysed cemeteries were located in different types of landscapes (agricultural, rural and urban) and represent various ways of using their area (currently used, closed, abandoned). The floristic list includes 440 species of vascular plants (437 in situ, 3 ex situ). The dataset demonstrates a sozological (Red-lists species) value of old cemeteries in Southern Ukraine. The cemeteries constitute refuges of native, rare and steppe flora and play a role of steppe habitat islands in a landscape almost completely transformed to arable land or urbanised. New information: This is the first dataset which contains information about flora of old cemeteries in Lower Dnipro region (Southern Ukraine). The dataset comprises 2118 occurrences of vascular plants (440 species) recorded in the years 2008-2021 in 13 old cemeteries of the Lower Dnipro region. The dataset includes information about 85 occurrences of rare species (23 species in situ, 3 ex situ) and 652 occurrences of 117 steppe species.

Top-down and bottom-up effects and relationships with local environmental factors in the water frog-helminth systems in Latvia.

Semi-aquatic European water frogs (Pelophylax spp.) harbour rich helminth infra-communities, whose effects on host population size in nature are poorly known. To study top-down and bottom-up effects, we conducted calling male water frog counts and parasitological investigations of helminths in waterbodies from different regions of Latvia, supplemented by descriptions of waterbody features and surrounding land use data. We performed a series of generalized linear model and zero-inflated negative binomial regressions to determine the best predictors for frog relative population size and helminth infra-communities. The highest-ranked (by Akaike information criterion correction, AICc) model explaining the water frog population size contained only waterbody variables, followed by the model containing only land use within 500 m, while the model containing helminth predictors had the lowest rank. Regarding helminth infection responses, the relative importance of the water frog population size varied from being non-significant (abundances of larval plagiorchiids and nematodes) to having a similar weight to waterbody features (abundances of larval diplostomids). In abundances of adult plagiorchiids and nematodes the best predictor was the host specimen size. Environmental factors had both direct effects from the habitat features (e.g., waterbody characteristics on frogs and diplostomids) and indirect effects through parasite-host interactions (impacts of anthropogenic habitats on frogs and helminths). Our study suggests the presence of synergy between top-down and bottom-up effects in the water frog-helminth system that creates a mutual dependence of frog and helminth population sizes and helps to balance helminth infections at a level that does not cause over-exploitation of the host resource.

An Extended dataset of occurrences of species listed in Resolution 6 of the Bern Convention from Ukraine.

Background: The dataset includes georeferenced occurrences of species listed in Annex I of Resolution 6 of the Bern Convention and, partly, in the Red Data Book of Ukraine. The dataset was compiled within the work of NGO "Ukrainian Nature Conservation Group" aimed to prepare a Shadow list of Emerald Network (European network Areas of Special Conservation Interest) in Ukraine - newly proposed territories aimed at conservation of particular species and habitats mentioned in Resolution 4 and 6 of the Bern Convention. The list was prepared in 2017-2020 for expanding the already existing Emerald Network of Ukraine. Based on actual registrations of flora and fauna collected and gathered by scientists and naturalists in a form of dataset, which is described in the following paper. New information: This dataset provides information about 29,938 occurrences of species from the territory of Ukraine listed in Annex I of Resolution 6 of the Bern Convention, as well as in the Red Data Book of Ukraine. This is the largest public dataset on occurrences of rare and endangered species from Ukraine till now. Data presented here laid the foundations for the proposal of 106 approved Emerald Network sites (2019), as well as for 148 Emerald Network sites that were nominated in 2020. New insights on the endemic species Centaureapseudoleucolepis Kleopow is provided, which was previously considered to be extinct, according to the IUCN Red List.