Ornis Hungarica. vol.10. (2000) p.141-147.
Migration of Acrocephalus species along the coast of the Black Sea
Loss of the necessary habitats along the migratory route could cause a population decrease in long-distance migratory birds. Knowledge on stop over sites and refuelling areas are very important in the conservation of migratory birds. The trans-Saharan, migrant Acrocephalus species have different migratory strategies between and within species.. In 1984 EURING started the Acroproject, an all-European research program in migratory strategies of Acrocephalus warblers. The Hungarian Ornithological and Nature Conservation Society organised ringing projects in the autumn migratory season at the coasts of the Black Sea, co-operating with local ornithologists near Burgas (Bulgaria 1990) and near Histria (Rumanian Dobrudja 1991-92). The birds were caught with mist nets, ringed, aged and weighed. We analysed the ratio of age groups, the body mass data and the percentage of heavy birds (>13g) recaptured, the average of stopover length of the Sedge Warbler (A. schoenobaenus), Reed Warbler (A. scirpaceus) and Marsh Warbler (A. palustris). The body mass and the percentages of heavy birds of the three species varied with age, year and site. The ratio of heavy birds were similar or higher than in West and South European stopover and refuelling sites. The stopover length of recaptures was short, and no mass gains were found.