After about 1000 in the morning the migration ceased to embark from Ras Siyyan toward Yemen, and migrants were seen moving south down the Djiboutian coast, some gaining elevation from the thermals that were no doubt gaining strength as the day warmed up. By 1100 almost no migration was visible from Ras Siyyan, and we spent afternoons searching for the main migration path. We searched to the south and to the west, speculating that the migration was building in the mountains to the west and no longer passing over Ras Siyyan.
It wasn't until 10 March, as we were leaving the field, that we located
the migration over two plateaus about 25 km south of Ras Siyyan on the
coast. Surprisingly though, migrants flying over these plateaus were
still heading south, away from Yemen. So, despite our best efforts, we never did determine where or how migrating raptors left Djibouti. We think that they may leave across a rather broad front, departing as individuals or groups when they attain enough elevation to make the crossing. For some they drift rather far south before heading over the sea. This supposition is bolstered (maybe) by the fact that the arrival of birds on the Yemen side of the straits does not appear to occur at a single location (H. and G. Welch pers.comm.).
|Looking for the migration. On this day we did not see any migration over these coastal plateaus.|
|Ali and Eleyeh looking north from atop one of the plateaus located about 25 km south of Ras Siyyan.|