Distribution and dynamic of castor fiber (castoridae, mammalia) population in forest-steppe rivers: A case of the state nature reserve privolzhskaya lesostep', penza region european Russia

Abstract

The work presents the first results of annual monitoring of a beaver population on the territory of Ostrovtsovskaya Lesostep' (State Nature Reserve Privolzhskaya Lesostep', Penza region). In 2014-2017 all water-courses and water-bodies, including the River Khoper, River Selimutka, River Yuzhnaya and several oxbows of the Khoper were investigated twice a year for assessing the beaver abundance using the method of settlements capacity. The mean density of dams was 7.7 dams/km of watercourse, the maximum was on the River Yuzhnaya-10.8 dams/km, and the minimum was on the River Selimutka-5.5 dams/km. During the study period 10 to 13 beaver settlements were observed, the total abundance of beavers tends to decrease (from 42 to 30 animals). The present density of beavers and a lack of food resources limit a further increase of the species abundance.