Michał Polakowski, Monika Broniszewska, Łukasz Jankowiak, Łukasz Ławicki, Marcin Siuchno
Ornis Polonica 2011, 52: 169–180
https://doi.org/10.12657/ornis.2011.3.1
Abstract: In the years 2007–2010, the dynamics of spring migration of geese and the importance of the Biebrza Basin (NE Poland) was determined. 18 foraging areas were found, where 1,200–40,000 individuals were recorded, depending on the area. Areas grouping the biggest concentrations were located in Wizna, Middle and Lower subbasins. The dominant species was the Greater White-fronted Goose Anser albifrons (mean about 90% of all geese), whose spring migration lasted for the shortest period, peaking in the second or third decade of March. The biggest concentration of this species accounted for ca 38,000 individuals. Bean Goose A. fabalis made up mean 9% of all geese and the largest flock was ca 2,850 individuals. The peak of spring migration in the second decade of March. Greylag Goose A. anser migration peaked in the first decade of March. Barnacle Goose Branta leucopsis and Pink-footed Goose A. brachyrhynchus were regularly recorded. A large increase in the number of geese during spring migration was noted over the last 35 years in the Biebrza Basin. In 2007–2010, during the migration peak, the maximal number of geese on their feeding grounds was estimated on ca 100,000–150,000 individuals. The Biebrza Basin is the most important region for Greater White-fronted Goose in Poland, bringing together ca 70% of the population migrating through Poland and 10% of the population wintering in Europe.
