Page 34 - Panuccio2012
P. 34
Circannual variation movements of Black Kite
of Ustica and 109 at Panarea, in the 2008 (Fig. be met by more experienced, older individuals of
3; Corso 2001, Panuccio et al. 2004, Mellone et larger size and/or in better physical condition (e.g.
al. 2007). These counts, compared to those made Gwinner 1990, Lindstrom et al. 1990, Beletsky
in autumn along the same flyway (Agostini 2002, and Orians 1993, Fransson 1995, Marra 2000). As
Panuccio et al. 2005), seem to suggest that lower a result, only high-quality phenotypes will be able
numbers of Black Kites use this flyway during to meet the high risks and energetic demands of
spring movements. Finally, the species is virtually early arrival (Sergio et al. 2007).
absent at watch-sites located on the Adriatic coast Feeding behaviour
of Italy (Gustin and Sorace 2004, Premuda et al. In the Central Mediterranean region migrating
2008), suggesting that the individuals migrating Black Kites are regularly seen feeding, as reported
through the Central Mediterranean belong mainly for the island of Ustica and the Strait of Messina
to the Italian population and do not cross the sea (Giordano et al. 1995, Panuccio and Agostini
en route to the Balkans, differently from other 2010). In Israel large flocks were recorded gathered
species (Premuda et al. 2008). to hunt termites and locusts (Bahat 1985, Shirihai
Arrival date at the breeding sites et al. 2000). These observations indicate that Black
At the breeding sites temporal patterns of Kites show opportunistic feeding behaviour when
settlement vary greatly. In northern Italy the plateau they meet significant food resources during their
is reached in less than 20 days, while at Doñana migratory journey.
National Park (Southern Spain) the population Water-crossing behaviour
built up rapidly at first, but new settlements span At the Strait of Gibraltar, similarly to autumn, Black
a period of about 2 months (Sergio et al. 2007). In Kites tend to cross the Strait at it’s narrowest point
central Italy Black Kites reach their breeding sites but wind drift largely occurs with the migration
not before the second decade of March (Battisti front sometimes expanded from Cape Trafalgar
et al. 2003, Panuccio and Agostini 2010). Older at the west to Guardiaro at the east (Finlayson
individuals arrive earlier than younger ones and 1992). On the European side of the Strait, kites are
the quality of territory is strongly correlated with often observed approaching the coast flying ”low,
the date of settlement, with the first individuals flapping continuously to avoid waves, and attempt
occupying the best quality sites, where annual to land along the coast, apparently exhausted”
breeding performance is better than in low (Finlayson 1992). As mentioned above, in the
quality ones (Sergio and Newton 2003, Sergio et Central Mediterranean area, Black Kites are more
al 2007). Younger individuals occupy low quality likely to migrate over the open sea in spring rather
territories later in the season (Sergio and Newton than in autumn, as shown by observations at the
2003). Older individuals defend their territory islands of the Tyrrhenian Sea (Panuccio et al. 2004,
better than younger ones highlighting that social Mellone et al. 2007). Nevertheless both at the Cap
dominance is age related for Black Kites (Sergio Bon promontory and at the island of Ustica they
et al. 2009). Early arrival of older individuals hesitate when facing the open sea: at both sites
is the result of the timing and efficiency of several kites often stop migration sometimes for
migration and could be probably promoted by: several days (Agostini and Duchi 1994, Panuccio
1) early accumulation of sufficient body reserves and Agostini 2010).
to depart from the wintering quarters, 2) rapid Conclusions
migration speed and optimal choices along the Differential timing of migration is population-
route, 3) social dominance at stopover sites, and dependent
4) high-feeding efficiency to counter the costs of The current state of research shows that the
potentially unfavourable conditions during the phenology of the Black Kite movements largely
migration journey (Berthold 1993, 1996). All
the above mentioned characteristics are likely to
34
