Analysis of the Recovery Data of the Great Cormorant Phalacrocorax carbo Ringed in the Russian Federation and on the Territory of Former Soviet States in 1939–2014

This study is based on recoveries of c. 86,850 Great Cormorants ringed in the Russian Federation during 1939–2014. Data were obtained from the Bird Ringing Centre of Russia. During 1939 to 2014 a total of 1667 Cormorant recoveries (1.9%) were added to the ringing database. The majority of the recoveries were made in the Caspian Sea, Azov Sea, Black Sea, Baltic Sea and in Kazakhstan inland waterbodies, including the Aral Sea (seven recoveries), Lake Alakol (46), Lake Balkhash (28), Kapchagay Reservoir (10) and Lake Zaysan (5). Non-breeding birds (assuming breeding at age > 3 years) comprised 89% of ring recoveries from 1939 to 1974, 95% from 1975 to 1990 and 100% from 1991 to 2014. This study is the first to describe the migration patterns for this species on a continental scale. From Kaliningrad in the west to Vladivostok in the east seven mega clusters of waterbodies and wetlands exist where Cormorants breed and were ringed. Although showing some overlap, birds belonging to a certain cluster were recovered in distinct wintering areas, often more than 2000 km from the breeding areas and separated by high mountain ranges. The general migration pattern is discussed for four geographic regions. The occurrence of east–west migration patterns is briefly discussed and deserves further study as well as the role of high mountain ridges possibly shaping the movements between summer and winter areas.