Migratory state: body mass and fat level of some passerine long-distance migrants during autumn migration in north-eastern Bulgaria
Mihaela Ilieva, Pavel Zehtindjiev
Directional behaviour of the Sedge Warbler (Acrocephalus schoenobaenus) studied in two types of orientation cages during autumn migration - a case study
Pavel Zehtindjiev, Mihaela Ilieva, Agnieszka Ożarowska, Przemysław Busse