During autumn migration across the Central Mediterranean, adult Honey Buzzards cross the sea at its narrowest point, between western Sicily (southern Italy) and the Cap Bon Peninsula (Tunisia). This study investigated the influence of prevailing winds and geography on the orientation behaviour of migrants during this sea crossing by observations over two islands, one on the northern side, the other on the southern side of the Channel of Sicily. The flock was taken as the sampling unit. Honey Buzzards reached the island of Marettimo, approx. 30 km off western Sicily and 130 km NE of the Cap Bon Peninsula, regardless of the direction of the prevailing winds (NW and S). By contrast, Honey Buzzards passed via Pantelleria, about 110 km SW of western Sicily and 70 km ESE of the Cap Bon peninsula, mostly during NW winds. Birds reached Pantelleria from the NE and left the island flying WNW They applied true navigational abilities in choosing the shorter crossing between Pantelleria and Tunisia and showing a curvilinear migration. Our results agree in part with the “optimal use of wind” hypothesis. In particular, wind, geography and navigational abilities seem to interact to shape the orientation behaviour of migrating Honey Buzzards, perhaps to minimize the risks of non-stop powered flight over the water.
Translator Disclaimer
N. Agostini
2004. Additional observations of age-dependent migration behaviour in western honey-buzzards Pernis apivorus. J. Avian Biol. 35: 469–470. Google Scholar
N. Agostini
,
A. Duchi
1994. Water-crossing behavior of Black Kites (Milvus migrans) during migration. Bird Behav. 10: 45–18 Google Scholar
N. Agostini
,
D. Logozzo
1995. Autumn migration of Honey Buzzards in southern Italy. J. Raptor Res. 29: 275–277. Google Scholar
N. Agostini
,
D. Logozzo
1997. Autumn migration of Accipitriformes through Italy in route to Africa. Avocetta 21: 174–179. Google Scholar
N. Agostini
,
D. Logozzo
,
M. Panuccio
2000. The island of Marettimo, important bird area for the autumn migration of raptors. Avocetta 24: 95–99. Google Scholar
Malara G. Agostini N.
,
F. Neri
,
D. Mollicone
1994a. La migrazione primaverile del Falco pecchiaiolo Pernis apivorus a Cap Bon (Tunisia) e sullo Stretto di Messina. Atti VI Conv. Ital. Ornit.: 451–452. Google Scholar
N. Agostini
,
G. Malara
,
F. Neri
,
D Mollicone
,
S. Melotto
1994b. Flight strategies of honey Buzzards during spring migration across the Central Mediterranean. Avocetta 18:73–76. Google Scholar
N. Agostini
,
M. Panuccio
,
B. Massa
2005. Flight behaviour of Honey Buzzards Pernis apivorus during spring migration over the sea. Buteo 14: 3–10. Google Scholar
T. Alerstam
1979. Optimal use of wind by migrating birds: combined drift and overcompensation. J. Theor. Biol. 79: 341–353. Google Scholar
S. Cramp
,
K. E. L. Simmons
(eds).
1980. The birds of the Western Palearctic. Vol. II. Oxford Univ. Press. Google Scholar
S. J. Hurlbert
1984. Pseudoreplication and the design of ecological field experiments. Ecological Monographs 54: 187–211. Google Scholar
H. Schmid
2000. Getrennte Wege: Der Herbstzug von juvenilen und adulten Wespenbussarden Pernis apivorus — eine Synthese. Orn. Beob. 97: 191–222. Google Scholar
K. Thorup
,
T. Alerstam
,
M. Hake
,
N. Kjellén
2003. Bird orientation: compensation for wind drift in migrating raptors is age dependent. Proc. R. Soc. Lond. (Suppl.) 270: 8–11. Google Scholar
Acta Ornithologica
Vol. 40 • No. 1
July 2005
Vol. 40 • No. 1
July 2005
geography
Honey Buzzard
migration
navigation
orientation
Pernis apivorus
water crossing
