About 20 thous. Black-headed gulls ringed in summer on Baikal, were found in winter in Western Europe, China and Vietnam. Gull birds occur not only in rocky shores of the lake, but also on swamps of the coast. The most simple species of terns found in Siberia is common terns. It nests on sandy and stony beaches and grassy islets.
Gulls are the main objects of ornithological studies.
At the Scientific-Research Institute of Biology of Irkutsk State University for 25 years about 100 thous. This is the biggest species of gulls occurring on Baikal. It feeds not only on fish, but other various food. Wintering grounds of these species are in Eastern Asia. The boundary lies at an altitude from 1500 to 1800 and more m above sea level.