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MARCH 2007                       SHORT COMMUNICATIONS                             57
         J. Raptor Res. 41(1):57–61
         E  2007 The Raptor Research Foundation, Inc.


                   LIPU (Lega Italiana Protezione Uccelli), Conservation Dep., Via Trento 49, 43100 Parma, Italy
         KEY WORDS: European Honey-buzzard; Pernis apivorus; mi-  of Levanzo and Favignana. This island is located in the
         gration; navigation; orientation; water crossing; wind.  northern half of the Channel of Sicily, ca. 130 km NE of
                                                    the Cap Bon Promontory (Tunisia, Fig. 1). Monte Falcone
           During migration, European Honey-buzzards Pernis api-
                                                    is its highest point, at 686 m. The observation station was
         vorus mostly use soaring flight, exploiting thermal currents
                                                    located at an altitude of ca. 500 m. Pantelleria is a volcanic
         over land. Because thermals are almost absent over water,
                                                    island (84 km 2 ), approximately 110 km SW of western Si-
         travelling there requires more energetically-expensive
                                                    cily and 70 km ESE of the Cap Bon Peninsula, in the
         powered flight (Kerlinger 1989) and European Honey-buz-
                                                    southern half of the Channel of Sicily (Fig. 1). The obser-
         zards are reluctant to undertake long sea crossings. How-
                                                    vation station was located along the western coast (Punta
         ever, each spring, thousands of migrants wintering in west-
                                                    Fram) at an altitude of ca. 100 m. At this island the highest
         central equatorial Africa cross the central Mediterranean
                                                    elevation inland (Montagna Grande) reaches 836 m. Like
         to reach their breeding areas in central-eastern Europe
                                                    Pantelleria, Panarea is a volcanic island (3.5 km 2 ), located
         (Cramp and Simmons 1980). During this sea crossing,
         the migrants concentrate at a narrowest point (approx.  approximately 65 km NW from the Straits of Messina
         150 km) leaving the African mainland from the Cap Bon  (Fig. 1). The observation station was at the island’s highest
                                                    point, ca. 400 m a.s.l. Finally, at the Straits of Messina the
         Peninsula en route to western Sicily, and also later at the
                                                    observation station was located along the Sicilian slope,
         Straits of Messina (Agostini et al. 1994a, 1994b, Agostini
                                                    over the Peloritani Mountains at an altitude of ca. 500 m.
         and Logozzo 1998, Corso 2001, Agostini et al. 2006). More-
                                                      Previous studies made at the Cap Bon Promontory and
         over, at least some of European Honey-buzzards crossing
                                                    at the islands of Marettimo, Ustica and Pantelleria, showed
         this Mediterranean area use alternative paths, reaching the
                                                    that European Honey-buzzards of the same flock tended to
         Italian Peninsula directly via Ustica and Lipari Islands
                                                    remain together in front of the water barrier because the
         (Fig. 1; Panuccio et al. 2004, Agostini and Panuccio
                                                    first individuals making a decision (crossing or not) were
         2005, Agostini et al. 2005a). In doing so, they undertake
                                                    followed by the others (Agostini et al. 1994a, 1994b, 2005a,
         a further water crossing flying over the Tyrrhenian Sea,
                                                    2005b). Thus, a flock-member did not act and orient in-
         bypassing the Straits of Messina. Unlike the Straits of Mes-
                                                    dependently. For this reason, in our statistical analysis, we
         sina, where migrants are reported mostly during head
                                                    considered the flock as sampling unit to avoid pseudo-
         winds (Agostini 1992), at Ustica, European Honey-buz-
                                                    replication of the data (Hurlbert 1984, see also Agostini
         zards move through during tailwinds, making a faster
                                                    et al. 2005a, 2005b). To investigate the circadian pattern of
         and energetically less-expensive flight over water (Agostini
                                                    migration, each observation day was divided into three
         et al. 2005a). The aim of this study was to investigate fac-
                                                    time periods: morning (0800–1159 H), midday (1200–
         tors shaping the pathways of European Honey-buzzards in
                                                    1559 H) and afternoon (1600–2000 H, solar time). Hourly
         the central Mediterranean basin during spring migration
                                                    meteorological data from the two study areas (Pantelleria–
         by simultaneous observations at four watch-sites, Maret-
                                                    Marettimo and Straits of Messina–Panarea) were recorded
         timo, Pantelleria, Panarea (Lipari Islands) and the Straits  at the meteorological stations of Pantelleria and Reggio
         of Messina (Sicilian side).
                                                    Calabria, respectively, and obtained at the Italian web site
         STUDY AREA AND METHODS                     of the Weather Underground Inc. (
                                                    htm). Observations were interrupted only because of rain
           Observations, using binoculars and telescopes, were
                                                    and/or poor visibility. Contingency tables were used to test
         made between 25 April–20 May 2004, the peak of the
                                                    the influence of prevailing winds and of the time of the
         spring migration of the European Honey-buzzard in the
                                                    day on the migratory flow through the Channel of Sicily
         Mediterranean basin (Cramp and Simmons 1980). Maret-
         timo is a small (12 km 2 ) mountainous island, approximate-  (Marettimo-Pantelleria) and eastern Sicily (Straits of Mes-
         ly 30 km from western Sicily and 20 km west of the islands  sina-Panarea).
         1 Present address: Mediterranean Raptor Migration Net-  Pantelleria–Marettimo. At these two sites, 325 flocks
         work, Via Carlo Alberto 4, 89046 Marina di Gioiosa Jonica,  (216 at Pantelleria, 109 at Marettimo) and 54 solitary in-
         Italy; Email address:  dividuals (19 at Pantelleria, 35 at Marettimo) were re-
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