Le Pin laricio (Pinus nigra laricio) est-il une espèce clé pour la Sittelle corse (Sitta whiteheadi) ?

Abstract

Endemic to Corsica Island, in the Western Mediterranean, the Corsican Nuthatch Sitta whiteheadi inhabits mainly the stands of Corsican Pine Pinus nigra subsp. laricio, although it is also present in other coniferous forests, e.g. the Maritime Pine P. pinaster which also covers large areas. The present study points out the major role played by Corsican Pine forests which hold higher densities of nuthatches than Maritime Pine forests. Seed shells seem to be a key factor. The seeds of Corsican Pine can be easily open by nuthatch’s bill which cannot break those of Maritime Pine. Finally, we examine the relationships between nuthatches and Corsican forests in an historical perspective. The nuthatch has probably been on Corsica since at least the middle of the Pleistocene. Since this time, important climatic changes have occurred in the Mediterranean, producing deep changes in the composition and distribution of vegetation. Throughout this period, the Corsican Nuthatch probably depended on Corsican Pine forest for its survival