Zehtindjiev, P. & F. Liechti (2003)

A quatitative estimate of the spatial and temporal distribution of nocturnal bird migration in south-eastern Europe - a coordinated moon-watch study.

Further information

Avian Science 3: 37–45



In SE Europe, the spatial and temporal distribution of nocturnal migration is hardly known. With the moon-watching technique the passage of 5603 nocturnal migrants was recorded during 419 observation hours at 28 sites spread over Bulgaria, SE Romania and northern Greece. Mean migratory traffic rate was 1400 in autumn and 900 in spring. Migration intensity was similar along both E-W and N-S gradients. Flight directions were virtually opposite between seasons, with a slight shift from SSW to S during the autumn and from NNE to N during the spring. These results indicate that a high proportion of nocturnal migrants along the eastern flyway do not circumvent the eastern Mediterranean Sea, but cross the sea on a broad front. This is in contrast to the migration along the western fly-way, where a majority of mainly long distance migrants take south-westerly directions towards the Iberian Peninsula and thus avoid a long sea crossing.
Keywords: Nocturnal migration, moon-watching, migratory intensity, flight direction, SE-Europe.