Catch numbers at ringing stations is a reflection of bird migration intensity, as exemplified by autumn movements of the Great Tit (Parus major)

Results from six ringing stations located along sea coast (maximally 517 km apart) were used to check if the method of catching birds in traps (mist-nets, heligoland) can be applied in analysing the real pattern of daily migrants migration. On the basis of catch dynamics of nearly 440 000 Great Tits, it was possible to demonstrate that the method of catching can be used successfully in studies of the daily passage of migrants, not only in order to probe the overall intensity of migration, but also to analyse migration routes and the influence of atmospheric conditions on birds' movements. It was found that migrating Great Tits cover the area uniformly, but atmospheric conditions disturb the passage.