Crossing the sea en route to Africa: autumn migration of some Accipitriformes over two Central Mediterranean islands

Abstract

Agostini N., Premuda G., Mellone U., Panuccio M., Logozzo D., Bassi E., Cocchi L. 2004. Crossing the sea en route to Africa: autumn migration of some Accipitriformes over two Central Mediterranean islands. Ring 26, 2: 71-78. Observations were made on the autumn migration of Accipitriformes over the islands of Marettimo and Pantelleria, located between western Sicily and Tunisia (Central Mediterranean). A total of 7451 raptors was counted between 24 August and 12 September 2003, mostly adult Honey Buzzards Pernis apivorus 4045, and Black Kites Milvus migrans 2489. Mixed-age flocks were regularly reported for the Black Kite (1956 adults and 533 juveniles estimated) confirming information transmission concerning orientation behaviour in this species. Although in the Honey Buzzard juveniles tend to migrate later than adults, crossing the Mediterranean on a broad front mostly after mid-September, we observed some mixed-age flocks, estimating the passage of 3830 adults and 215 juveniles. In particular, over Pantelleria we recorded in seven cases juveniles in flocks of adults heading towards WNW, presumably learning (similarly to juvenile Black Kites) the shortest route over water to reach Africa from this site. A total of 72 Egyptian Vultures Neophron percnopterus 62 adults, 6 juveniles and 4 sub-adults was counted over Marettimo confirming that their greatest concentration during autumn migration through Italy occurs at this island. In this species, all juveniles were seen migrating in flocks of adults. Finally, the passage of hundreds of Marsh Harriers Circus aeruginosus was reported, mostly over Pantelleria. Among adult harriers, it was possible to estimate the passage of birds belonging to different sex classes; unlike in the previous studies made in central, southern continental Italy and Malta during autumn migration, adult females outnumbered adult males (372 vs 298 individuals). Finally, considering the huge number of Accipitriformes observed, Pantelleria, so as Marettimo, should be enclosed among Important Bird Areas for the autumn migration of raptors in the Mediterranean basin.

Orientation of native versus translocated juvenile lesser spotted eagles (Clanga pomarina) on the first autumn migration

“…These two routes converge over Turkey and Syria as LSEs travel toward Suez. Few LSEs cross the Mediterranean through the Straits of Gibraltar and via Sicily ( Agostini et al, 2004 ; Onrubia et al, 2011 ; Giordano, 1991 ); these flyways are clearly of minor importance compared with the southeastern flyway.…”

Analysis of the Spatial Migration Patterns of Adult Honey Buzzards (Pernis apivorus) During Spring and Autumn in the Central Mediterranean

“…In this period, adult Honey Buzzards follow the Italian mainland and northern Sicily concentrating at the Strait of Messina; they reach Africa through the Channel of Sicily, at least part of them via Marettimo and Pantelleria islands, like during spring migration (Fig. 1, Agostini and Logozzo 1997, Agostini et al 2000, Agostini et al 2004b, 2005b. It is interesting to note that adult Honey Buzzards passing via Pantelleria choose the shortest flyway over water to reach Africa, changing their orientation behaviour leaving the island heading WNW.…”

Potential importance of wind patterns and guidance opportunities for the conservation of the Egyptian Vulture Neophron percnopterus in Italy

“…At that time, the Italian population was estimated at 9-13 breeding pairs, and at least 19-22 juveniles were expected to migrate in the three years (Liberatori and Penteriani 2001, Sarà et al 2009. Surveys made at Marettimo reported that all juveniles were migrating in flock with adults, and sometimes in mixed-species flocks with adult European Honey Buzzards Pernis apivorus and Black Kites Milvus migrans (Agostini et al 2000(Agostini et al , 2004. In fact, every year, hundreds of Honey Buzzards and Black Kites migrate in flocks along this route from Western Sicily to Cap Bon (Agostini et al 2000), thus representing a good chance for inexperienced juvenile Egyptian Vultures to find the right path by following them.…”