Autumn migration of the black grouse Lyrurus tetrix in the south of the Onega bay of the White Sea in 2019

Observations of bird migrations were carried out in the first half of October 2019 on the Onega Peninsula in the south of Onega Bay of the White Sea. In coastal biotopes, a high number of black grouse Lyrurus tetrix with non-standard behavior was traced. Observations showed that birds immigrated to coastal landscapes from the opposite shore of the bay, crossing it through an extended sea area. According to the survey data of the local residents, such migrations occur every 4 years in the fall. This phenomenon is supposed to be local behavioural adaptation. At other points in the south of the White Sea such observations are absent.