Addicions a l'estudi dels rapinyaires "(Falconiformes)" dels massissos de Sant Llorenç del Munt-Serra de l'Obac, Montserrat i zones envoltants

Abstract

This work mainly focuses on the study of the status, nourishment and protection of Raptors in the aforesaid area of Catalonia, with a surface area of 486 km 2 , in wich a total of 17 species have been detected, 8 of which are surely nesting, 2 have been more or less recently extinguished, and the rest have been observed in their passing or accidentally. The approximate status of the nesting species is (in pairs): Accipiter gentilis (10- 15), Accipiter nisus (10-15), Buteo buteo (8-12), Hieraaetus fasciatus (3-4), Circaetus ga- Llicus (3-4), Falco peregrinus (3-5), Falco subbuteo (2-3) and Falco tinnunculus (10-15); a diversity of 2.77 bits has been observed in a sample of 140 km 2 . In what concerns their feeding, we may stress the importance of Oryctolagus , consumed by Hieraaetus fasciatus, Buteo buteo , and Accipiter gentilis ; due to the fact of having seen their number reduced through myxomatosis, Oryctolagus seem to have been substituted by Lacerta lepida, Rattus sp. and passeriformes. We may point out the presence of Chiroptera ( Pipistrellus sp.) in the diet of Falco peregrinus and Crustacea ( Nephrops norvegicus ) in F. tinnunculus , the last one being a product of garbage disposal areas; in all the rest, the feeding patterns are similar to the ones found in the rest of Iberia. The problems of preservation of Raptors have no doubt reached their critical point, due to the great quantities of them that are captured, to the destruction of their nests and environment, and to the poisoning they are suffering through phytosanitary products.