Łukasz Ławicki, Artur Staszewski, Ryszard Czeraszkiewicz
Ornis Polonica 2010, 51: 93–106
https://doi.org/10.12657/ornis.2010.2.1
Abstract: During the years 1991–2008, 41 roosts grouping at least 100 individuals of the Bean Anser fabalis and White-fronted Geese A. albifrons were being monitored in Western Pomerania (NW Poland). The major roosts of geese were located in the lower Odra River valley, on Miedwie Lake, the Szczecin Lagoon, Kamieński Lagoon, and in the 1990s also on Świdwie Lake. During November censuses, 5 088–45 005 and 605–51 206 individuals of Bean and White-fronted Geese were counted, respectively. During January counts, the number of Bean Geese varied from 503 to 51 056, whereas that of White-fronted Geese between 10 and 8 783 birds. Up to 12–16 thousands of Bean and up to 40 thousands of White-fronted Geese were maximally counted during spring migration. Western Pomerania provides important stopover grounds for these two goose species in Poland, which concentrate approximately 30% of Bean and 60% of White-fronted Geese during autumn migration, and about 50% of their wintering population. In the case of Bean Goose, up to 6% of the population wintering in Europe occurs in Western Pomerania. Over a span of 20 years, numbers of geese occurring during autumn migration have declined in Western Pomerania, which may result from the change of their migration routes as well as local depletion of the food resources. The trend for wintering geese is difficult to determine due to highly variable weather conditions between years and due to massive returns of geese as early as in mid-January in some years.
