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Five European slow worms (Anguis) have mostly parapatric distributions. Two species, A. fragilis and A. colchica, are widely distributed across the western and eastern parts of the genus range. Their contact zone runs from the north-eastern Balkans, through Pannonia to northern Central Europe. In northern Poland, the contact zone has been located approximately between the North and East European Plains. Here, we present the first mitochondrial and nuclear DNA data from Finland and the coastal Baltics. We demonstrate that A. fragilis enters the East European Plains, where it is presumably distributed along the Baltic coast. Our data indicate that A. colchica is present more inland and to the north of Riga. The genetic structure suggests three independent postglacial colonization events in the Baltics (two by A. colchica). The presence of the two species, A. fragilis and A. colchica, should be considered by the conservation legislations of Lithuania, Latvia and Russia.

The slow-worm lizards (Anguis) comprise five species occurring throughout most of the Western Palearctic. Although these species are relatively uniform morphologically – with the exception of A. cephallonica, which exhibits a quite unique morphology – they are genetically deeply divergent. Here, we provide detailed distribution maps for each species and discuss their biogeography and conservation based on updated genetic data and a robust distribution database. We pay particular attention to the so called ‘grey zone’, which typically represents secondary contact zones and in some cases confirmed or presumed hybrid zones. Four of the five species live in parapatry, while only two species, A. cephallonica and A. graeca from the southern Balkans occur in partial sympatry. Further research should focus on the eco-evolutionary interactions between species in contact, including their hybridization rates, to reveal deeper details of the slow-worm evolutionary and natural history.

In order to use an integrated approach for studying the influence of risk factors on the distribution of the native turtle species E. orbicularis and accompanying invasive species (T. scripta and N. procyonoides) in the northeast of their range, we used GIS modelling and a database (GAEZ, human footprint, CliMond) of 55 preselected variables, which represent a system of bioclimatic and anthropogenic factors. The main variables that influenced the results were factors related to temperature. There was a high correlation (r = 0.6) between the species distribution model’s habitat suitability for E. orbicularis and the corresponding “human footprint” values within the European part of the species’ natural range. Its unpretentiousness towards anthropogenic factors would likely help the further expansion of its range in eastern Europe, because the areas with the highest habitat suitability (r &gt, 0.7) were projected to increase 3.3-fold. When comparing the E. orbicularis model to those obtained for N. procyonoides and T. scripta, we concluded that N. procyonoides could be dangerous because it occupies similar habitats (the degree of correlation is reasonably high in the north of their range (r = 0.5) in Latvia). An expansion of the range of Trachemys scripta is also possible in the future within the northern territories. Therefore, when developing the turtles’ protection algorithms, it is also necessary to take into account the influence of invasive species.

The aim of our study was to provide a first overview of the population genetic structure of the invasive Chinese sleeper,Perccottus glenii, (Actinopterygii: Odontobutidae) in European water bodies. This species originates from inland waters of north-eastern China, northern North Korea and the Russian Far East. The 1172 bp long portion of the cytochrome b gene was sequenced from Chinese sleeper specimens collected from a variety of water bodies in Belarus, Bulgaria, Hungary, Germany, Latvia, Lithuania, Poland, Russia (European part) and Ukraine. Our study revealed that the invasive Chinese sleeper in Europe consists of at least three distinct haplogroups that may represent independent introduction events from different parts of its native area; i.e. three founding populations: (1) Baltic haplogroup that may originate either from fish introduced inadvertent from Russia or from some unidentified source (release by aquarists). So far, this haplogroup has been found only in the Daugava basin in Latvia. (2) East-European haplogroup that may originate from an unintentional introduction to the Volga basin in Russia and has expanded westward. So far, this group was recorded in the Volga, Upper Dnieper and Neman drainages in Belarus, Lithuania, and Russia. (3) Carpathian haplogroup, that originated from individuals unintentionally introduced with Asian cyprinid fishes to Lviv region in Ukraine and are now widely distributed in Central Europe.

Audial surveys of anuran amphibians (frogs, toads and similar) are cost-effective and allow for the coverage of large areas, but they are usually regarded as unsuitable for population size estimations due to imperfect detection. Our study demonstrated a method for obtaining minimum adult population size estimates from vocalising anuran counts by using sex ratios, life history and vocalising behaviour parameters from other studies. We collected data from 2016 to 2018 for seven taxa on 65 plots (each 25 km2) representing the entirety of Latvia. Among taxa, average breeding waterbody audible detection probabilities ranged from 0.56 to 0.88 per plot, minimum adult frog density (MAFD) estimates were from 12.0 to 51.7 individuals per km2, but the estimated fraction of population covered by MAFD varied from 57 to 86%. The least accurate density estimates were in taxa with brief calling activity and quiet mating calls (Rana temporaria), and in taxa with a calling activity dependent on the numbers of males in a pond (Bufo bufo). Our study suggests that lek-breeders would be more suitable than explosive-breeding taxa for minimum population size estimates from audial data. The use of MAFD allowed for coarse minimum population size estimates for the entire country from the audial monitoring data, these ranged from 3.7 ± 0.5 thousand (Bombina bombina) to 1.64 ± 0.47 million (B.bufo) adults.

Amphibians have been greatly affected by invasive species through direct predation and competition. The invasion in Eurasia of Perccottus glenii (the Chinese sleeper) triggered by climate change may have detrimental consequences for the Fire-bellied toad (Bombina bombina) because the invader can feed upon B. bombina eggs, toads and juveniles. We used correlative species distribution models (SDMs) to infer competitive interaction between the invader and native species and found a significant level of correlation (r=0.636) between both SDMs, meaning there is a considerable overlap of areas of similar habitat suitability related to the species and a potential for competition. For strategical management purposes we mapped areas in Latvia where there are lesser chances for negative interactions between the both species, and where unwanted contact and/or competition between the invader and the toad can be avoided. DOI: http://dx.doi.org/10.5755/j01.erem.74.4.21093

The article describes the potential distribution area of B. bombina and fi gure out the signifi cant climatic factors of the species at a home range scale. Th is species is listed on Appendix II of the Bern Convention and on Annexes II and IV of the EU Natural Habitats Directive. It is protected by national legislation in many countries, occurs in many protected areas, and is listed in many national and sub-national Red Data books and lists. We collected the occurrence records and a set of climatic variables including 19 factors from 10’ resolution historical (summarizing annual trends, seasonality and extreme conditions during 1961-1990) and projected data (2050) available at the CliMond database. As a result, under climate predictions for 2050 there may be a substantial north and north-west shift of optimal habitat. Under such a scenario B. bombina populations may suff er mostly in the east and south of Ukraine. Under the modelled scenario the species representation in protected areas throughout the home range should be considered, but especially in Ukraine.