The article is focused on the main aspects of the ecology of the populations of Rana temporaria and R. arvalis in two functional zones of Losiny Ostrov National Park, differing in the level of recreational impact. An increase in the population density of frogs was noted in the specially protected natural zone of the national park, with Rana arvalis predominating everywhere. Moreover, the highest growth rates in numbers (5–6 times) were recorded for fingerlings. Optimal living conditions for these amphibians are characterized by high humidity (above 70%) and ground air temperatures above 15 °C.

Keywords: age structure of the brown frog population, amphibians in urban conditions, brown frogs, brown frogs in recreational areas of the city, daily activity of brown frogs, Losiny Ostrov National Park, Rana arvalis, Rana temporaria