Mass Concentrations of Bramblings Fringilla montifringilla in Europe 1900-1983: Their Dependence upon Beech Mast and the Effect of Snow-Cover

Data on beechmast in south Sweden, Denmark, Germany and Yugoslavia, on snowcover in Germany and on records of mass concentrations of Bramblings in Europe between 1900 and 1983, are presented. Bramblings concentrate in areas with a widespread rich beechmast crop and try to winter as far north-east as possible. Extensive snow-cover forces movements to the south and south-west, where the birds may reconcentrate if there is also a good beechmast crop. No periodicity in mass occurrences or beechmast could be detected. Interrelationships between mass concentrations indicate that Middle Europe, Belgium, Luxembourg and northern France are visited by the same winter population, while those areas to the east and to the west of the south-western migration axis would seem to receive different wintering populations.