Page 1 - AgostiniPanuccio2010

J. Raptor Res. 44(2):136–142

E 2010 The Raptor Research Foundation, Inc.

WESTERN MARSH HARRIER (CIRCUS AERUGINOSUS) MIGRATION
THROUGH THE MEDITERRANEAN SEA: A REVIEW

NICOLANTONIO AGOSTINI1 AND MICHELE PANUCCIO
Universita` degli Studi di Pavia, Dipartimento di Biologia Animale, Via Ferrata 1, 27100 Pavia, Italy

and
MEDRAPTORS (Mediterranean Raptor Migration Network), Via Carlo Alberto nu4, 89046 Marina di Gioiosa

Jonica, Italy

ABSTRACT.—The Western Marsh Harrier (Circus aeruginosus) is a summer visitor in northern, eastern, and
central Europe. Some birds, mostly juveniles and adult females, winter in the Mediterranean region, while
others cross the Sahara to winter in tropical Africa. Unlike other Accipitridae, which use primarily soaring
flight over land during migration, Western Marsh Harriers tend to move on a broad front, with long,
powered flights over water. In the last two decades, several researchers have investigated the migration
of this species through the Mediterranean basin using direct observations, radar, band recovery data, and
satellite telemetry. We here present a short review of these investigations and results.

KEY WORDS: Western Marsh Harrier; Circus aeruginosus; Mediterranean; migration; orientation; water-crossing.

MIGRACIO´ N DE CIRCUS AERUGINOSUS SOBRE EL MAR MEDITERRA´ NEO: UNA REVISIO´ N

RESUMEN.—Circus aeruginosus visita el norte, este y centro de Europa durante el verano. Algunas aves,
principalmente jo´venes y hembras adultas, pasan el invierno en la regio´ n mediterra´nea, mientras que otros
cruzan el Sahara para pasar el invierno en A´ frica tropical. A diferencia de otros Accipitridae, que usan
principalmente el vuelo elevado sobre a´reas terrestres durante la migracio´ n, en C. aeruginosus los individuos
tienden a moverse en un frente amplio y realizan vuelos largos e impulsados sobre el agua. En las u´ ltimas
dos de´cadas, varios investigadores han estudiado la migracio´ n de esta especie en el Mediterra´neo usando
observaciones directas, datos de radar y de anillos recuperados, y telemetr´ıa satelital. Aqu´ı presentamos una
revisio´n corta de esas investigaciones y sus resultados.

[Traduccio´n del equipo editorial]

The Western Marsh Harrier (Circus aeruginosus) is through the Mediterranean basin using direct ob-
a partial migrant (Cramp and Simmons 1980). Un- servations, radar, band recovery data, and, recently,
like populations breeding in southern and western satellite telemetry. In particular, Strandberg et al.
Europe, those breeding in northern, eastern, and (2008) reported satellite telemetry data of 33 migra-
central Europe are complete migrants. Some of tions (20 autumn and 13 spring migrations) of 17
these birds winter in the Mediterranean basin, while Western Marsh Harriers (eight adult females, six
others cross the Sahara to winter in tropical Africa, adult males and three juveniles) of the population
with relatively few crossing the equator (Ferguson- breeding in southern Sweden. Here we provide a
Lees and Christie 2001). Marsh harriers have rela- short review of these investigations.
tively long wings and, during migration, they fre-
quently use powered flight (Spaar and Bruderer AUTUMN MIGRATION
1997), undertaking the crossing of large bodies of
water (Kerlinger 1989, Bildstein 2006). As a result, Peak Passage Date. The peak passage through the
they tend to move on a broad front (Cramp and Mediterranean, as reported by systematic direct ob-
Simmons 1980, Gensbol 1992, Zalles and Bildstein servations at several sites, occurs in September,
2000). In the last two decades, several researchers mostly during the second and third ten-day period
have investigated the migration of this species of the month (Finlayson 1992, Rebassa 1995, Agos-
tini and Logozzo 1997, Jonze´n and Pettersson 1999,
1 Email address: nicolantonioa@tiscali.it Agostini et al. 2003, Sammut and Bonavia 2004,
Roth and Corso 2007). Peak migration day varied
notably among years, ranging from 9–23 September

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