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March 1997 Short Communications 85
September 1993
M. Covello Malta
Figure 2. Variations in migration of Honey Buzzards from 14-30 September 1993 on Mount Covello and Malta.
gregate until adult buzzards can show them the shortest grating in flocks of adults. This would explain why the
route across the Mediterranean. Honey Buzzard is commonly seen in Malta, where the
African coasts are more than 400 km away.
Study Area and Methods Flocking behavior might have another function. Stud-
ies carried out on the Cap Bon promontory (Tunisia)
Migrating Honey Buzzards were counted in the Cala-
brian Apennines and from a post on the slopes of Mount during the spring migration of Honey Buzzards and
Covello (elevation 700 m) from 24 August-5 October Black Kites ( Milvus migrans) have shown that these rap-
1993 and 1995. Buzzards were also counted on the Island tors cross the Channel of Sicily more frequently when
of Malta. There, the observation post was situated on the migrating in large flocks (Agostini and Duchi 1994, Agos-
highest point on the island (approximately 250 m eleva- tini et al. 1994a). This behavior suggests that flocking is
tion) from 6 September-5 October 1993 and 1995. A important for water crossing because an increase in flock
total of 334 hr of observations were tallied at Mount Cov- size increases the probability the journey over water will
ello using 10 X 50 binoculars and a total of 188 and 177 be successfully completed (Agostini and Duchi 1994,
hr of observation were tallied using 10 X 40 binoculars Agostini et al. 1994b).
on the Island of Malta in 1993 and 1995, respectively.
Results Resumen.—Observaciones de Pernis apivorus emigrando
A total of 1095 Honey Buzzards were counted in the a traves de el centro Mediterranean fueron hechos en los
Calabrian Apennines and more than 90% were observed Calabrian Apennines (el sur de Italy) del 24 de agosto-
between 24 August-12 September. The number of mi- 5 de octubre 1995, y en Malta del 6 de septiembre-5 de
grating buzzards showed a bimodal distribution with octubre 1993 y 1995. En los Calabrian Apennines, 1095
peaks occurring in late August and after the first week of
P. apivorus fueron observados, con un maximo de 237
September (Fig. 1). In both years, there was overlap in
pajaros emigrando e el 7 de septiembre. Casi todos los
the migration periods of adult and juvenile buzzards but
P. apivorus fueron observados entre el 24 de agosto-12
over twice as many adults were observed in both years
(adults = 346, juveniles = 136). In 1995, the number of de septiembre. En Malta, 483 y 83 P. apivorus fueron con-
adults observed was also significantly greater than in 1993 tados en 1993 1995, respectivamente, con casi todos
y
2
(X = 6.38, P< 0.05). contados despues del 15 de septiembre. Estos resultados
A total of 483 Honey Buzzards were counted on the
proponen que P. apivorus jovenes aprenden la ruta mas
Island of Malta in 1993 but only 88 were counted in 1995.
corta para cruzar el centro Mediterranian durante el
More than 97% of them were observed in September and
primer ano de migracion cuando van en bandadas con
this corresponded with counts in the Calabrian Apen-
adultos que han hecho la migracion antes.
nines (Fig. 2).
[Traduccion de Raul De La Garza, Jr.]
Discussion
Some authors have shown that migrating birds orient Acknowledgments
better when they fly in groups (Keeton 1970, Rabol and
We are greatly indebted to Paul Portelli, Francesco
Noer 1973, Wallraff 1978, Von Helbig and Laske 1986),
especially when groups contain adults that can show to Cecere and Alberto Zangirolami for their valuable collab-
correct migration route (Kerlinger 1989). Our observa- oration. Our particular gratitude goes to Allen Fish,
tions suggest that juvenile Honey Buzzards learn the Keith Bildstein and Javier Bustamante for their useful
shortest route to cross the central Mediterranean by mi- comments on the manuscript.
