Bombina bombina

Based on field surveys in 2013 – 2015 of four local populations of Bombina bombina and Pelophylax ridibundus in spawning lakes in the Medveditsa river valley (Saratov region) it was found that the body length (SVL) and weight of mature females of B. bombina and P. ridibundus ranged from 31.1 to 49.7 mm and from 63.1 to 138.1 mm; from 2.64 to 8.43 g and from 25.4 to 181.0 g, respectively.

Morphometric characteristics of Bombina bombina males and females were done. 10 traits were measured and 10 indices were calculated for a sample of B. bombina from the population of the lake Cherepashie (the Medveditsa river valley, Lysogorsky district, Saratov region). Only some traits show significant sex-ual differences in B. bombina.

The size, weight and sexual structure of Pelophylax ridibundus and Bombina bombina populations was analyzed during their spawning migrations in 2013 - 2015 in four lakes of the Medveditsa River flood-plane (Saratov Region, Lysogorsky District).

The structure of the spawning anuran taxocenoses in five floodplain lakes in the Medveditsa river valley in 2009 - 2016 was analyzed. Degradation of the populations of the three most numerous species and a decreased degree of dominance of the spadefoot toad were established. This degradation strongly affects the species with a longer distance of spawning migrations - the severity of the changes sequentially decreases in the row: Pelophylax ridibundus → Pelobates fuscus → Bombina bombina.

The nutrition of Bombina bombina and Pelophylax lessonae collected in three habitats of the northwestern Upper Oka region in 2006 - 2014 was studied. The feed composition of Pelophylax lessonae reduced to the autumn by the abundance and taxonomic diversity, epigeious beetles and ants to predominate. Bombina bombina mainly feeds on ants and arachnids in the autumn.

Literary information about the batrachofauna of the Orenburg nature reserve is incomplete and contradictory. Data on the specific composition and abundance of amphibians in the Orenburg Nature State Reserve at its five cluster territories by the results of our 2015–2020 inventory are presented. The previously published materials about amphibians on the cluster territories “Talovskaya Steppe”, “Burtinskaya Steppe” and “Aytuarskaya Steppe” have been supplemented.