Changes in distribution and numbers of the breeding population of the Common Crane Grus grus in Estonia

Abstract

The aim of this study is to analyse population trends and distribution of the breeding population of the Common Crane in Estonia. The population size and density of the Common Crane in Estonia has increased several times over the last 30 years (1910-2001). According to the most recent population estimatź, about 5800 pairs were breeding in Estonia in 1999. The mean population density of the Common Crane in Estonia was 17.4 pairs/100 km2. Most of the Common Cranźs are nesting in mires (5300 pairs, 9I%),pimarlly in fens (4200 pairs, 727o).The mean population density in fens, transition mirźs and raised bogs was 41.3, 38'3 and 15.9 pairs/100 km2,respectively. Several factors have probably contributed to thź recent increase in the Common Crane breeding population in Estonia, e.g. the emergence of new nesting sites connected to human activity, locally higher spring tempźratures and conservation activities.