Status and trends of the common crane Grus grus on the western route

Abstract

The evolution of 40 wintering areas of Grus grus in the south-west of teh Iberian Peninsula has been studied, including the traditional wintering places of this species on its western route. Eight of these areas harboured 50% of the whole population using this route, and none of the 40 areas showed a decline in the number of birds during the study period. At present the number of cranes in each area is much greater than in the 1979-1980 winter. No geographical trends have been observed regarding the magnitude of the increase, which is closely related to that observed for the whoel Spanish and Palarctic populations. Despite the emergence of some new wintering areas, the magnitude of the increase is greater in more southerly parts of the range. This may be a consequence of greater diversity and availability of food in these latitudes. The influence of enhanced international protection and agricultural food sources on the appearance of new wintering areas is discussed.