The Nature Reserve «Dniprovsky-Orilsky» occupies unique ecosystems of the floodplain of the middle part of the Dnieper River, where the medium-flooded forests (black poplar and willow forests, elm-Tatarian maple oakeries, and pine forests at the sandy second terrace) predominate. Marshy, wet and dry meadows, sandy steppes, salt marshes, floodplain lakes and isles support the diversity of habitats. Reptiles, like ectothermic organisms, are known to be sensitive to temperature and humidity, which are directly influenced by climate change. Due to the variety of species and their habitats’ conditions, it is important to study the possible effects of climate change on each species and each place of their residence separately. Studies in more or less natural conditions of the Reserve allow minimizing the impact of the anthropogenic factors on the number and diversity of species. To produce accurate inventories we use the method of linear transects created at survey sites modified by Dinesman and Kaletskaya (1952) with a width of transects up to 3 meters. The length of the survey route depended on the availability for an accountant, but was not less than 1.0 km in all cases. The surveys were conducted during the period of maximum daily activity of reptiles in the spring-summer period on specified routes. The density of reptiles was described as the number of individuals per hectare of an averaged ecosystem. In aquatic and wetland ecosystems, the population density of European pond turtle and dice snake were determined as a number of specimens per 1 km of the waterbody’s bankline. During almost 30 years of observation, eight reptile species have been registered on the territory of the Dniprovsky-Orilsky Nature Reserve, among which three species (Coronella austriaca, Natrix tessellata and Dolichophis caspius) have been recorded in the last decade. In recent years (since 1972), the average increase in the temperature of the surface air layer in Ukraine was more than 1 °С. In winter, in the central regions of the country, the highest increase in the average monthly air temperature is observed. The excess reaches 2 °C and more. Climatic changes can be the reason for the invasion and the number growth of the dice snake and the appearance of the Caspian whipsnake within the Reserve. In the context of general climate change, there is a tendency to reduce the population density of the pond turtle, sand lizard and grass snake. At the same time, there is a gradual increase in the number of steppe vipers. Preserving current temperature trends in the coming years can create favourable conditions for another reptile species – the blotched snake (Elaphe sauromates) – to penetrate into the Reserve, but also negatively affect the hygrophilic species. Increasing the risk of summer fires in the Nature Reserve «Dniprovsky-Orilsky» is one of the most threatening factors for the conservation of the terrestrial biota, including reptiles.
Acanthocephalan size and sex affect the modification of intermediate host colouration