Ornis Hungarica. vol.5. (1995) p.23-32.
Study of autumn migration and wing shape of Sedge Warblers (Acrocephalus schoenobaenus) in Southern Hungary
Migration dynamics of Sedge Warblers (Acrocephalus schoenobaenus) were studied at the Sumony Bird Observatory 45'58' N, 17'56' E in the southern part of Hungary. The wing length and wing shape indices of juvenile birds captured during different stages of migration were analysed as well. The migration of adult birds was more concentrated than that of juvenile birds. The migration peak for adult birds was in late July and early August (median date 10 August). There were four migration periods in the case of juvenile birds. Migration was very intensive in late August and early September (median date 17 August). On the basis of wing length, it is obvious that birds with short wings were in majority in reedy parts of southern Hungary in late July. These birds probably belong to populations breeding in the Central Europe. In late August and early September, the rate of birds with longer wings increased. These birds might come from Southern Scandinavia and the Baltic region and they use Hungary as a stopover site.