Mołoniewicz, L., B. Zając, P. Stachyra, J. M. Szymura & M. Pabijan

Extension of the known northeastern range limits of the agile frog (Rana dalmatina) in southern Poland. pp. 325-334.

Abstract. The precise delimitation of range boundaries is imperative for the conservation of amphibians in the wake of intense habitat conversion and global climate change. Despite decades of study, the distributions of many amphibian species in Central and Eastern Europe are still relatively uncharted. In this contribution, we report 40 new breeding localities of the agile frog (Rana dalmatina) in southern Poland, extending the known northeastern range of this species by ca. 100 km. In 2018–2020 we surveyed the Roztocze region in southeastern Poland, a predominantly forested area with extensive agriculture and numerous small water bodies. We focused on the presence of egg clutches of R. dalmatina at breeding sites and confirmed species identification using barcoding and a newly developed, PCR-based mitotyping technique that allows for rapid and inexpensive discrimination between R. dalmatina and two other, broadly sympatric, European brown frog species, R. temporaria and R. arvalis. Out of a total of 121 ponds, 40 (33%) contained at least one R. dalmatina clutch. Most of the localities were located in the Roztocze National Park (RNP) or its vicinity, and some were located more distantly, close to the Polish-Ukrainian border. The breeding sites of R. dalmatina were mostly small water reservoirs located in diverse habitats, but always within or close to forest. Our results indicate the existence of another, possibly isolated, enclave of R. dalmatina at its northeastern range limit in southern Poland. Moreover, we show that RNP and its surroundings are an important stronghold of R. dalmatina in Poland, providing crucial information for the conservation of peripheral populations of this species.

Key words. Amphibia, Anura, Ranidae, barcoding, geographic range, mitotyping, peripheral populations, Roztocze.