Characteristics of soaring birds' spring migration over inland SE Bulgaria
We investigated the scale and characteristics of spring migration of soaring birds in Bourgas district, SE Bulgaria during three 5-day periods in March (27 th -31 st ), April (20 th -24 th ) and May (12 th -16 th ) 2008. Simultaneous counts were carried out from six observation points in two separate areas (Karnobat and Sredets), located 24.5 km and 37.3 km inland from the Black Sea coast, respect
