In the French Pyrenees, 3,000-5,000 adult capercaillie Tetrao urogallus occupy 2,200 km? of habitat fragmented into 93 forested areas. These areas are further subdivided into habitat islands varying in size from 5 to 12,000 ha, separated by distances of 5-100 km. The total number of leks in these islands is 600-700. Winter habitat is often limited, representing only 11% of the geographic range in some areas. Nevertheless, capercaillie show great plasticity in regard to winter foods. The birds often winter in pure stands of Abies alba in the French Pyrenees which is in contrast to those in the boreal forests, where capercaillie are dependent on Pinus silvestris. Brood habitats are even more limited in the French Pyrenees and, in some areas, represent only 6% of the geographic range. To compensate for the lack of brood habitats within forests, hens often rear their young in prairies or brushlands. Although the metapopulation of the Pyrenees apparently contains only 18 viable populations, the geographic range remains stable due to both dispersal of young from productive populations and habitat plasticity.
Key words: brood habitat, capercaillie, French Pyrenees, habitat fragmentation, population viability, Tetrao urogallus
Emmamuel M?noni, Office National de la Chasse, F-31800 Saint Gaudens, Cedex, France
Philippe Landry, Office National de la Chasse, Saint-Benoist, F-78610 Auffargis, France
C. Berducou, Office National des Forets, F-6400 Pau, France