Migrant Landbird Study Group

Promoting collaborative research for migratory landbirds across flyways

Dutch English French German Spanish Turkish

Operation Baltic

Study species: Passerines

Research topics: Climate Change; Migration; Migration routes; Migratory connectivity

Project organiser: Bird Migration Research Station, University of Gdańsk

Status: Active

Operation Baltic is a network of three bird ringing stations Mierzeja Wiślana, Bukowo-Kopań and Hel at the Baltic coast, which have ringed and measured migrant birds each year with constant standards since 1960 to this day. It is a citizen science project, conducted by the Bird Migration Research Station (BMRS) of the Faculty of Biology at the University of Gdańsk in Poland. Operation Baltic focuses on studying the biology and ecology of passerines and other migrants in spring (March – May) and autumn (August – November) passage along the Polish coast of the Baltic Sea. During more than 60 years of field work Operation Baltic’s volunteers have ringed more than 1,6 million of birds of 207 species. More than 1 million migrants have been measured in detail (wing and tail length, wing formula, fat score and weight) by calibrated ringers, which is the largest set of consistent biometric data on vertebrates in the world. Thousands of ringed birds have produced more than 10 000 ringing recoveries for many species, which confirmed that the southern Baltic coast is a crossroad of migration routes for birds within Euro-African migration system.

Operation Baltic focuses on mist-netting small passerines. The most abundant species, caught, ringed and measured are the short- and middle-distance migrants: Goldcrest Regulus regulus, Robin Erithacus rubecula, Great Tit Parus major, Blue Tit Cyanistes caeruleus and Long-tailed Tit Aegithalos caudatus. But the long-distance migrants, heading to sub-Saharan Africa, constitute about 12% (more then 180 000 individuals so far) of our ringed birds. The most numerous species of this group are: Reed Warbler Acrocephalus scirpaceus, Willow Warbler Phylloscopus trochilus, Blackcap Sylvia atricapilla, Garden Warbler Sylvia borin, Redstart Phoenicurus phoenicurus and Pied Flycatcher Ficedula hypoleuca. Larger birds, such as shrikes, woodpeckers, raptors and owls are also caught. Among the 209 species that have been ringed at Operation Baltic about 20 are vagrants from Siberia, Central Asia and North America. Since 1995 we have conducted orientation tests on about 54 000 migrants at ringing stations in Europe and the Middle East, following a simple field method devised by Prof. Przemysław Busse at Operation Baltic. The standards of catching, ringing and measuring the migrants at Operation Baltic have been kept constant since 1960. Thus the numbers of birds ringed every year and their measurements provide tools for monitoring migrants, which enable us to follow long-term changes in migration timing and the evolution of their morphology in response to changing environmental conditions.  Results of the Operation Baltic have been used in more than 300 research papers, 7 PhD dissertations and several tens of MSc and BSc projects. The Operation Baltic’s standards are the base of the methods applied at other ringing stations in Poland and in other countries of Europe and Africa. More information at: