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Migration ecology of raptors in the Mediterranean
Figure 3 - Honey buzzards, island of Ustica, May 2010.
these technologies, visual observation remains a recovered during winter both in Europe and in
widespread and irreplaceable practice, allowing Africa. In addition, I created a model to explain
the collection of a huge sample of data that the distribution of short-toed snake eagles in Italy
provides reliable information on the timing of using published and unpublished data on their
migrations as well as population trends (Kjellén nest localization.
and Roos 2000, Agostini et al. 2007, Bildstein Finally, in order to provide hypotheses to
et al 2007). Visual observations were also chosen explain different behaviours in raptors I used the
because, in comparison with other methods, software created by Professor Colin Pennycuick.
they have a lower impact on budgets. This was a This software allows the calculation of energy
significant factor given that the research included consumption rates in the two different types
here had limited financial support and was of flight, namely powered flapping flight and
largely self-funded. Finally, direct observations soaring-gliding flight. For this calculation, the
permit the implementation of communication body mass (Kg), wing span (m) and wing area
activities involving a large number of people in (m²) of a bird model are required. This software
monitoring activities, and constitute therefore calculates an estimate of energy rates in Watt
a good approach for popularising knowledge of assuming an absence of wind. Additional details
wildlife and evolutionary biology and, in the final as well as theoretical support are provided in
instance, protecting migrating raptors (Bildstein Pennycuick (2008). This method was largely
2006). used in its previous versions as well (Hedenström
Nonetheless, visual observation was not the only 1993, Pennycuick 1989, 1997).
method used in this dissertation. I also analyzed
ring recoveries of western marsh harriers ringed
during the breeding season in Europe and
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