Le comunità ornitiche degli ambienti aperti dellaSila Grande (Calabria) con note sull’apparentecontrazione demografca di Saxicola rubetra,Regulus regulus e Carduelis spinus
Sorace A.Abstract:
Breeding bird communities of open habitats in the Sila Grande Massif (Calabria, Southern Italy) with notes on the possible decrease of Saxicola rubetra, Regulus regulus and Carduelis spinus populations. During the 2008 spring, breeding bird communities of open habitats were investigated by means of transect method. In 8 areas, 14 transects (overall length 12,06 km) were carried out recording only the individuals in the 50 m belt on both sides of the transect. The richness of species (36) and the diversity index were higher than in open habitats of other areas of Centre and South Italy likely due to the large availability of bush areas in some transects and the relatively scarce distance from wood area of other transects that increased the presence of edge species. Among the 16 recorded species of conservation concern, Lullula arborea was particularly abundant (3.9 ± 2.4 pairs/km). This species with Saxicola torquata and Turdus viscivorus were the most common species in the transects. Along the study transects and also during survey in the surrounding woods, Regulus regulus e Carduelis spinus were not recorded. Singing males of Saxicola rubetra were recorded only in early season suggesting that they were migrant individuals. These data suggest a drastic decrease of the populations of these three species that breed in Sila Grande mountains at the most southern edge of their areale.