The programme In Greece focuses on 5 species which are subject to different conditions. The species are:
- Blackbird (Tudrus merula): endemic/indigineous – overwintering – migratory
- Song Thrush (Turdus philomelos): partly endemic – overwintering – migratory
- Mistle Thrush (Turdus viscivorus): endemic – overwintering – migratory
- Field Fare (Turdus pilaris):endemic – migratory
- Redwing (Turdus iliacus): overwintering –migratory
To observe the migration of these 5 species of cichlids, a method evaluated and approved by the French National Observatory of Wild Life and Habitats (ONFSH, 2004) is used and is described as the recording of song in the Blackbird, Song Thrush and Redwing during their night-time movements.
For these observations, 5 bio-acoustic stations were positioned (Telinga Pro type Pip. 4) along principal known migratory paths in Greece. The stations operated all night from 23.00 until 03.00 the next day from 1st January until 31st March. The bio-acoustic stations were placed at suitable points to avoid confusion with overwintering birds and in regions with good acoustics (far from busy roads, airports etc.). The digital cassettes were recorded by wild life specialists and the data was recorded on special IMPCF recording forms.
The ensuing data from hourly recordings every night were then fed into a data base. The date of the pre-nuptial migration is determined from the number of song recordings per hour per night throughout the study period. In addition, the beginning of migration and the various “pics” which appear in succession according to the birds’ origin can also be determined.
The choice of observation points for the Cichlids was made according to the following strict criteria:
- Zones known to be on Cichlid migratory paths and, where possible, not supporting overwintering populations.
- Five bio-acoustic stations constitute a satisfactory number.
- With the most comprehensive geographic coverage of Greece (regions, identified migratory paths etc) in order to elicit results of national significance. These stations were positioned on a “south-west/north- east axis”, a main axis of migratory return so that actual migratory movement can be clearly distinguished from domestic movement. To achieve this, altitude was chosen with care, so that there would be no confusion with local movement (from mountain to plain).
- For the extraction of valid results, stations were chosen where there was zero overwintering, so that true migratory movement in birds could be recorded. These stations included precipitous shores and hills known for their paths.
The position of the bio-acoustic stations for observation of migrating Cichlids in Greece, mentioned above, based on the literature to date and the known migratory paths for the species in Greece are as follows:
- LEFKADA: Actium
- MESOLONGHI
- ATTICA: Kalentzi Marathon
- EVIA: Kimi
- EVIA: Drosia Chalchida