"Nidificación del alcaudón real, "Lanius meridionalis", en agrosistemas del norte de España"

Abstract

The plant cover type more frequently used by the southern grey shrike, Lanius meridionalis, in agrosystems of northern Spain was that of shrubs, both thorny (mainly blackberry, Rubus ulmifolius) and thornless (mainly kermes oak, Quercus coccifera). Some couples made their nests in piles of vine shoots (cut branches of vine, Vitis vinifera), a fact not published anywhere until now. Out of 64.4% of the layings at least one chick fledged. The height and depth of the nests found in the vegetation had some effect in such percent of success. Both clutch size and brood size were negatively related with the percentage of cereal crops and positively related with the percentage of olive and almond groves at a distance of 1 km in diameter around the nest. The possible effects of vegetation upon the nesting of the southern grey shrike in the agrosystems are also discussed.