Every year, about half of the 9000 species of birds known migrates from countries in the northern hemisphere to tropical countries or travels between the two hemispheres. The primary reason for this is attributed to lack of food in the winter months, especially for species which feed on insects, like the Honey buzzard, and on fish (because of frozen lakes).

The periods of migration are the intermediate ones, which means Autumn and Spring. For the European birds of prey the destination for wintering is almost always Africa, but there are some partial migratory birds and short range birds which move from northern to southern Europe.

The straits like those of Gibraltar, Bosphorus and the Sicilian canal, represent a sort of natural bridge between Africa and Europe. Many of the birds of prey, especially those of greater dimensions, concentrate themselves on the straits for migration because incapable of crossing long sea extensions.

These birds prefer to glide: they use the rising currents which form on earth (thermals) to gain altitude and then they dive. On the sea the thermals don't form and therefore the birds would be obliged to cross long distances actively moving their wings, with enormous energy consumption.

The thermals are often characterized by the presence of thousands of individuals. During migration these birds, which are not usually social, group themselves in flocks and they migrate together. The group gives courage, it works as a reciprocal stimulus and helps in the search of rising currents.

The Messina Strait has less migration than the Strait of Gibraltar and the Bosphorus, even though the 40000 birds of prey of the Messina Strait estimated by Thiollay in 1977 are a significant figure.

The birds concentrate themselves over Cape Bon, in Tunisia, where they attend the favorable meteorological conditions for the crossing of the Sicilian Canal, long about 150 km.

Once they have arrived in Sicily they follow the southern dorsal of mountains and arrive on the Strait. From here, using as a spring board the Peloritani Mountains they cross the short strip of sea and arrive on the coast of Calabria.

The arrival front is vast and extends from Capo dell'Armi to Palmi for a total of about 60 km. The passage though, is usually concentrated on a 2-3 km coast strip depending on the winds present over the Strait.

Once arrived on the Coast of Calabria the birds search for another thermal to reach the Aspromonte and ascend the Apennine.

Gruppo Universitario Faunistico Ornitologico
(Universitary Group for Wildlife and Ornithology)
Viterbo