European cranes shift their wintering area northwards:
new evidences from radiotagged birds
Juan C. Alonso, Javier A. Alonso, José H. Martínez, Serge Avignon and Pierre Petit
Abstract. During the last two decades an increasing number of Common Cranes using the western route have spent the winter in northern Spain (Gallocanta) and France, probably in
response to the increasing agricultural food resources and protection mesures at these areas. Our results on radiotagged cranes confirmed this trend: the percentage of marked cranes wintering in France increased from 12% in 1998-99 to 23% in 1999-2000. Four of these cranes spent their frst winter in Spain as
juveniles with their parents, but remained in France as immatures in subsequent winter seasons, while no bird shifted southwards. These changes in wintering sites suggest that part of the northward shift observed during the last decades in the winter range could be due to the higher mobility of immature
birds, which tend to aggregate at areas with more cranes and, thus more abundant food resources, while most adult pairs would probably tend to remain faithful to their traditional wintering areas in southwestern Iberia and Morocco.
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There has been a northward shift in the winter range of the western population of Common Cranes, associated with increasing agricultural food resources. The increase in France corresponds with a decrease
in SW-Iberia and, probably, Morocco.
The crane population migrating through western Europe |
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( Published in Proceedings IV European Crane
Worshop, Verdun, France, November 2000)
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