Effects of wind conditions on the autumn migration of waterfowl between the White Sea area and the Baltic region

Radar studies on the autumn migration of marine ducks and geese from the White Sea area to the Baltic Sea show that the main part of the populations migrates during following winds or weak crosswinds. During the typical non-stop flight 600-700 km to the Gulf of Finland no compensation for wind drift occurs. Over the mainland of S Finland wind drift of as much as 450 from the mean direction in calm weather (2300) was recorded. Departures from the White Sea occur preferably during following winds, weak winds or in calm weather, but not at all during strong headwinds or during crosswinds that would cause a drift of at least around 200 from the normal direction.