Knowledge about the distribution of living organisms on Earth is very important for many areas of biological science and understanding of the surrounding world. However, much of the existing distributional data are scattered throughout a multitude of sources, such as taxonomic publications, checklists and natural history collections and often, bringing them together is difficult. A very successful attempt to solve this problem is the GBIF project, which allows a huge number of researchers to publish data in one place in a single standard. Our dataset represents a significant addition to the occurrences of amphibians in the Volga, Don riverine basins and adjacent territories. The dataset contains up-to-date information on amphibian occurrences in the Volga river basin and adjacent territories, located for the most part on the Russian plain of European Russia. The dataset is based on our own studies that were conducted in the years 1996-2020. The dataset consists of 5,030 incident records, all linked to geographical coordinates. A total of 13 amphibian species belonging to nine genera and six families have been registered within the studied territory, although the distribution of amphibian species in this region of Russia has not yet been fully studied. This is especially relevant with the spread of cryptic species that can only be identified using molecular genetic research methods. The main purpose of publishing a database is to make our data available in the global biodiversity system to a wide range of users. The data can be used by researchers, as well as helping the authorities to manage their territory more efficiently. All occurrences are published in GBIF for the first time. Most of the data are stored in field diaries and we would like to make it available to everyone by adding it in the global biodiversity database (GBIF).

In this paper, we present our dataset containing up-to-date information about occurrences of small mammals (Erinaceomorpha, Soricomorpha and Rodentia) on the territory of Samarskaya Luka. It is a bend of the Volga River in the southern part of the forest-steppe zone of the Russian Plain (European Russia). This unique territory is surrounded on almost all sides by water. The dataset summarises small mammal occurrences noted in long-term studies in Samarskaya Luka from 2000 to 2020. A major part of the dataset was obtained during our helminthological study of small mammals. Besides, some data were attained when studying the ecology of tree-dwelling rodents. Our studies of small mammals were conducted by trap lines and direct observations in the wild. The dataset includes 8147 records of erinaceomorphs, soricomorphs and rodents of 26 species (of total 28) belonging to three orders, nine families and 21 genera. It is based on the research of the staff of the Institute of Ecology of the Volga River Basin of the Russian Academy of Sciences and the Zhiguli State Nature Reserve. The distribution of erinaceomorphs, soricomorphs and rodents in Samarskaya Luka has not been completely studied and further investigation may well discover new small mammal habitats. Our dataset contains new information on occurrences of erinaceomorphs, soricomorphs and rodents in Samarskaya Luka (European Russia). All occurrence records of 26 mammal species with georeferencing are published in GBIF for the first time. The occurrence data are stored in our field journals and we would like to make them available to all researchers.

The Volga basin is one of the most industrially-developed regions of Russia with a high degree of anthropogenic impact on natural ecosystems. Human influence negatively affects the species diversity and number of animals, including reptiles. There are no endemic species in the reptile fauna of the Volga basin. The herpetofauna of the region makes up 25% of the reptile fauna of Russia (Dunaev and Orlova 2017). We began to study the fauna of reptiles and their distribution in the Volga basin in 1988. Although we registered 20 reptile species in the Volga basin to date, apparently this is not a complete list of species in the region (Bakiev et al. 2004, Bakiev et al. 2009a, Bakiev et al. 2015, Kirillov et al. 2020). The distribution of reptiles in this region is not fully understood. Our dataset contains information on reptile occurrences in the Volga River basin. The dataset is based on original research by the staff of the Laboratory of Herpetology and Toxinology and Laboratory of Population Ecology of the Institute of Ecology of the Volga River basin of the Russian Academy of Sciences and Joint Directorate of the Mordovia State Nature Reserve and National Park “Smolny”. A total of 5,086 occurrences of 20 species are published for the first time with georeferencing. Many of these reptiles are listed in regional Red Data Lists. The European Pond Turtle Emys orbicularis (Linnaeus, 1758) is included in the IUCN Red List with the category “Near Threatened”.

In different months during 2015-2017, the abundance and sex-age structure of the Sand lizard (Lacerta agilis) were studied on two transects. Parallel transects were established in the southeastern part of the cluster area «Burtinskaya steppe» of the Orenburg State Nature Reserve (Russia). The length of each transect was 3 km. The width of the mineralised plowed strip between the transects was 9-11 m. Transect 2 was located in the area burnt in August 2014, while transect 1 was situated in the area burnt in August 2016. In terms of size and external morphological traits, the captured Sand lizards were divided into three groups: juvenile individuals, adult males, and adult females. After measurements, the marked animals were put back to the places of capture. The number and sex-age structure were restored on transects in May-June, after the first winter following the fire impact. We found that on transect 1, the species abundance at late April-early May 2015 was almost three times higher (18.67 individuals / km) than on transect 2 (6.67 individuals / km). However, at late May 2015, the species abundance on both transects became almost the same (12.67 individuals / km in transect 1 against 11.33 individuals / km in transect 2). The juvenile individuals suffered from the fire influence more than adults. After the 2016 fire (i.e., in mid-May 2017), the proportion of one-year-old individuals was 21.2% of the total number of Sand lizards recorded in transect 1, while it counted 67.3% of the total number of Sand lizards recorded in transect 2, burnt in 2014. We believe that the rapid recovery of the abundance and sex-age structure in the Burtinskaya steppe was associated with the migration of Sand lizards through the mineralised strip separating the burnt and non-burnt transects.

Обитание живородящей ящерицы в степной зоне на южной границе ареала (участок «Буртинская степь» заповедника «Оренбургский») приурочено к участкам с азональной (преимущественно луговой) приручьевой растительностью на гидроморфных почвах. Биотопические и микроклиматические условия для существования здесь лесного гигрофильного вида обусловлены наличием родника и вытекающего из него ручья. Трансформацию местообитаний вызывают пожары, обустройство туристических маршрутов, деятельность бобров. На исследуемой территории все ящерицы сконцентрированы на двух площадках общей площадью 0.004 км 2. Ориентировочная плотность популяции, выявленная при количественном учете, достигает 7.8 ос./1000 м 2. Сравнение размеров тела живородящих ящериц из «Буртинской степи» с популяциями из Пензенской и Самарской областей, также находящихся на южной периферии ареала, существенных различий не выявило. Самки живородя� существенных различий не выявило. Самки живородя� выявило. Самки живородящей ящерицы заповедного участка «Буртинская степь» отличаются от самок большинства популя� большинства популя� популяций из других частей ареала большей плодовитостью, а детеныши меньшей массой, чем в регионах, расположенных севернее. Появление потомства у ящериц отмечено в более ранние сроки, чем в большинстве регионов восточноевропейской и азиатской частей ареала. Анализ данных по репродуктивной биологии (длина тела самок, участвующих в размножении, сроки появления потомства, плодовитость, размерные характеристики новорожденных) показал их сходство с аналогичными для ящериц из популяции Среднего Поволжья.