Molecular studies support the hypothesis that Corsica Island was a glacial refugium for a number of forest birds during the Pleistocene. We focused on the Corsican nuthatch (Sitta whiteheadi), an endemic passerine strongly associated with the laricio pine (Pinus nigra laricio). The range of laricio pine has been impacted by the Pleistocene glacial periods and forest has been recently fragmented by cutting and fires. Using both molecular (mitochondrial and nuclear) and morphological characters, we assessed the variation within the nuthatch population. Our results are consistent with the hypothesis that the Corsican nuthatch endured through the late Pleistocene and Holocene climatic variations, and sustained the subsequent cycles of forests reduction/expansion. The results also suggest that the recent anthropization of the landscape resulted in the isolation of a cluster of populations in the northern part of the island. The fragmentation of the habitat of the nuthatch may impede the future of the bird by creating isolated population units between which the gene flow is reduced.

Macro- and megafossil studies are of great value in palaeoecology because such evidence is spatially precise, directly radiocarbon dated, and usually taxon-specific. Here, we present new macro- and megafossil data from ten sites from the Gredos Mountains, central Iberian Peninsula, that suggest persistent forest cover through the late Holocene, with a widespread belt of pinewoods in the highlands of the Central Iberian Mountains. Well-preserved pine cones found at several sites revealed that both Pinus sylvestris and Pinus nigra were present in the area during the middle and late Holocene at locations of important biogeographical interest. The P. sylvestris forests represent one of the southernmost locations of its entire range. P. nigra was not known to have occurred in central Spain during the Holocene; it was found at the westernmost edge of its range in siliceous soils, a rare environment compared with the rest of its distribution. Finally, we explored the potential for obtaining a long pine chronology from central Iberia using tree-ring measurements and radiocarbon dating of pine subfossil logs.