Relazione tra indici Riproduttivi del fagiano di monte (Tetrao tetrix Linnaeus 1758) e parassiti e caratteristiche ambientali .

The Black Grouse is suffering a dramatic declining in all alpine district; for its conservation it is needed an appropriate hunting management that takes in account the local specific dynamics and ecology. We have studied the dynamics (1997-2002) of Black Grouse in Val Brembana game preserve (52000 ha, areas censured 7657 ha), in terms of reproductive index (pullus/female; n = 642), in 7 sectors (divided in the north, south, east and west areas), related to the land cover and relative changing (from 1970 to 1995) and parasites. The reproductive index changed by years. by sectors and from north (2.94) to south (1.91) and west (2.85) to east (2.02) areas. The dynamics of different sectors showed common pattern (synchrony) for the west sectors, and the sector 1 (Northeast), probably the source population, was not correlated to the others. No relations were detected between land cover, changing and reproductive index. The parasite contents were different in terms of Capillaria spp. with the east sector showing higher values. The content of Capillaria spp. was negatively correlated to the reproductive index (r = -0.86, P = 0.02)