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SHORT COMMUNICATION
J. Raptor Res. 45(1):88–92
E 2011 The Raptor Research Foundation, Inc.
WIND EFFECTS ON VISIBLE RAPTOR MIGRATION IN SPRING AT THE STRAIT OF MESSINA, SOUTHERN ITALY
MICHELE PANUCCIO1
University of Pavia, Dipartimento di Biologia Animale, Via Ferrata 1, 27100 Pavia, Italy
and MEDRAPTORS (Mediterranean Raptor Migration Network) via Mario Fioretti 18, 00152 Rome, Italy
KEY WORDS: European Honey-buzzard; Pernis apivorus; flock- Messina and concentrating over the islands of Ustica and
ing behavior; raptor migration; water crossing. Panarea (Panuccio et al. 2004, Agostini et al. 2007, Mel-
lone et al. 2007). Previous studies have focused on the
Many species of raptors winter in Africa and breed in relationship between migratory behavior of European
central and northern Europe, migrating north in the Honey-buzzards and weather conditions at the Strait of
spring and south in autumn (Gensbøl 1992, Ferguson-Lees Messina (Agostini 1992, Agostini et al. 1994b, 2007).
and Christie 2001). During their travels, the birds face a
natural barrier: the Mediterranean Sea. Due to their mor- In this report, I analyze the influence of wind conditions
phology, the energy consumption of raptors in powered on the migratory patterns of raptors at the Strait of Mes-
flight increases disproportionately with body mass. As a sina by comparing the migratory passage of European
result, raptors use different flyways according to their de- Honey-buzzards and Circus spp., the most abundant spe-
pendence on soaring-gliding flight (Kerlinger 1989, Zalles cies reported at the site (Giordano 1991, Corso 2001).
and Bildstein 2000). Anatomy is not the only factor influ-
encing the decision of whether to cross the sea: weather STUDY AREA AND METHODS
conditions, experience, body condition, time of day, and
flocking behavior may also influence the timing of crossing Observations were made between 27 March and 31 May
(for a review, see Kerlinger 1989, Bildstein 2006). 2004 from a migratory observation point located along the
continental coast of the strait, at the narrowest point be-
Eagles and Eurasian Buzzards (Buteo buteo) avoid cross- tween Sicily and continental Italy (approx. 3 km; Fig. 1).
ing the central Mediterranean between North Africa and Observers used the same observation point (38u13.569N,
southern Italy, which would entail a long water crossing 15u40.089E), on a hilltop between the villages of Scilla
(Agostini 2005). Conversely, in spring thousands of Euro- and Villa S. Giovanni at an approximate altitude of 300 m
pean Honey-buzzards (Pernis apivorus) cross the Channel asl, for the entire study period. This area was believed to be
of Sicily between Cap Bon Peninsula (Tunisia) and western the primary flyway for migrating raptors in the area (Agos-
Sicily, distance of about 150 km (Agostini et al. 2007). The tini 1992, Agostini et al. 1994a, 1994b, 1994c, 1995). Ob-
behavior of European Honey-buzzards is intermediate be- servations were made between 08:00 H and 18:00 H (solar
tween that of broad-winged raptors such as eagles and time) for a total of 660 hr (observations were interrupted
Buteos and that of relatively long-winged raptors such as only in case of heavy rainfall). Two researchers, equipped
Circus spp., and although they concentrate at narrow straits with 10 3 42 binoculars and 20–603 spotting scopes, ob-
and isthmuses, they are able to undertake long powered served simultaneously, making scans of the sky with binoc-
flights over sea (Agostini et al. 2005, Agostini and Panuccio ulars. Observers recorded species, age and sex classes,
2005). Black Kites (Milvus migrans) form migratory con- flight direction, and flocking behavior.
centrations between North Africa and southern Italy, fun-
nelling over the Channel of Sicily, whereas Circus spp. mi- Meteorological data from the Meteorological Station of
grate across a wider expanse, passing also over Malta Reggio Calabria Airport located on the continental side of
(Beaman and Galea 1974, Agostini and Duchi 1994, Agos- the strait 15 km south of the watchpoint was used for
tini and Panuccio 2010). The main migratory flow of rap- comparison to the observation data (www.ilmeteo.it). For
tors reaching the continental coast of Italy from Sicily is the analysis, hourly measures of wind strength and direc-
funnelled through the Strait of Messina, where up to tion were used.
30 000 raptors per year have been counted (Corso 2001).
However, between 3000 and 8000 raptors take a more di- The prevailing wind direction at the Strait of Messina
rect route to the Italian peninsula, bypassing the Strait of was compared to the migratory passage rates of three cat-
egories of raptors: the European Honey-buzzard, Circus
1 Email address: panucciomichele@gmail.com spp., and the total number of raptors (Accipitriformes).
The category of Circus spp. included Western Marsh Har-
riers (Circus aeruginosus), Montagu’s Harriers (Circus pygar-
gus), Pallid Harriers (Circus macrourus), and Northern Har-
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