The Abundance оf Black Grouse in Northern Eurasia

Abstract

This paper presents the estimate results of the average annual abundance of black grouse (Lyrurus tetrix L., 1758), made on the material of data bank (ISEA SB RAS) for groups of physico-geographical countries within the borders of the USSR 1990. On the East European and West Siberian plains, value of grouse abundance and total number were calculated on average separately for the first and second half of summer and in winter, mainly from 1960 to 2020, for physicogeographical countries – only for the first half of summer. The under-accounting of birds was revealed in the second half of summer on the both plains territory, which was made up with the help of additional calculations. As a result, value of the abundance and total number of birds were obtained for natural zones and subzones within Russia and the USSR, separately on the East European and West Siberian plains. A significant similarity of the grouse stock estimation results by weighted averages, separately by landscape groups, and by a simple average for the entire territory of a physico-geographical country or several of them in the first half of summer is shown. The second method of stock assessment compared with the first one gave results that differ for those plains within confidence intervals at a confidence level of 0.1. On the groups of physico-geographical countries territories in the first half of summer, the highest average annual values of the abundance and number of black grouse are appropriate of the European territory and the Urals as a whole, as well as in Western Siberia. The lowest values are typical for Central Asia and Kazakhstan.