The migration of rapacious birds

In Spring Mediterranean skies are full of millions of birds of every specie which come from the Sub-saharian Africa in order to nest in the European territory. Rapacious birds are the most flashy because of their size and because they fly only during the day enjoying thermal upward flows, that are bubbles made up of hot air which raise from the ground heated by Sun rays.
During their migratory journeys rapacious birds are used to concentrate in big groups in points where overcoming natural obstacles (such as long stretches of sea) is easier thanks to advantageous geographical conformations.
One of these points in Italy is Mount Conero. Thanks to its very short distance from the Balkan coasts (about 120 km) and to its 572 m height in a sheer drop over the coast, Mount Conero is used as a springboard by rapacious birds which want to cross the Adriatic sea. They reach the opposite cost in 3 h ½ with an uninterrupted flapping flight, as there aren’t thermal upwards flows over the sea.
Every year in April and May about 10.000 rapacious birds are registered in transit over the park. Among them, the largest groups are those constituted by honey buzzards, marsh harriers, kestrels and cuckoo hawks.
In addition, other species fly over the Conero in the same way the rapacious do, such as white and black storks and cranes.