Western Marsh Harrier (Circus aeruginosus) Migration Through the Mediterranean Sea: A Review

Differential wintering area selection in Eurasian Marsh Harrier (Circus aeruginosus): a ringing recoveries analysis

“…This fits with the results of visual observations carried out in the Mediterranean basin, both at migration bottlenecks and at wintering sites, that showed a stronger tendency for adult male Eurasian Marsh Harriers to migrate over longer distances than adult females, because an imbalance towards males has been observed during migration en route and from Africa, with the opposite trend at wintering sites in Italy (Agostini & Logozzo 2000, Agostini et al 2003, Panuccio et al 2005a, 2005b, 2012, Agostini & Panuccio 2010. It has been suggested that this latitudinal segregation of the sexes is promoted by sexual dimorphism, because females, being larger, are more adept than smaller males in taking larger prey items and coping with colder temperature, on the basis of the Bergman's rule (Cristol et al 1999, Panuccio et al 2005a.…”

“…In the analysis we considered only highly accurate data concerning dates and coordinates of capture and recovery with a maximum error of 50 km (EURING categories from 0 to 4). After filtering, we retained for analysis a total of 320 individuals ringed during the breeding season (10 May-10 July) and recovered during winter (15 October-28 February), selecting these periods according to the migratory phenology of the species (Génsbøl 2004, Strandberg et al 2008, Agostini & Panuccio 2010. It has been reported that some Eurasian Marsh Harriers do not settle in the wintering grounds before late autumn (Strandberg et al 2008); for this reason, we also repeated all the analysis using a subset of data (15 November-28 February).…”

“…Support is, however, provided by studies that show individuals from Western France are mostly resident (Bavoux et al 1992(Bavoux et al , 1994 while populations breeding in Scandinavian are largely long-distance migrants (Strandberg et al 2008). Some recent studies have investigated the movements of populations from limited parts of the marsh harriers breeding range by visual observations, traditional radio-telemetry and, more recently, by satellite tracking (Sternalski et al 2008, Strandberg et al 2008, Klaassen et al 2011, Agostini & Panuccio 2010). Here we analyse migration patterns of Eurasian Marsh Harriers using ringing recovery data from a large portion of Europe.…”

Migration of the Western Marsh Harrier to the African wintering quarters along the Central Mediterranean flyway: a 5-year study

“…Yet, harriers have morphology and size allowing them to use this flight style for a long duration (Spaar and Bruderer 1997;Panuccio et al 2013b;Agostini et al 2015). During both spring and autumn, large numbers of Western Marsh Harriers move through the Central Mediterranean flyway where substantial concentrations have been reported at several watchsites, peaking in late March/early April and in September, respectively (Agostini and Panuccio 2010). Previous field surveys made at different watchsites and during specific autumn migrations in 1996 and 2002 have suggested that, among adult Western Marsh Harriers, larger numbers of males head to the wintering quarters in Africa Logozzo 1997, 2000;Agostini et al 2003;Panuccio et al 2005).…”

“…Unlike broad and rounded winged species, which mostly migrate over land using soaring flight exploiting thermals and updrafts, harriers move on a broad front, undertaking long sea-crossings (for a review see Agostini and Panuccio 2010). Since thermals are very weak over water, at least in temperate zones, sea crossing implies a long powered flight with considerable expenditure of energy (Kerlinger 1989).…”