Role of the Mediterranean Sea in differentiating European and North African woodland bird assemblages

• Published in: Community ecology 2015-06, Vol.16 (1), p.106-114
• Main Authors: Correia, R. A, A. M. A. Franco, J. M. Palmeirim
• Format: Article
• Language: English
• Subjects: Animal Ecology; Biodiversity; Biodiversity conservation; biogeography; birds; Community & Population Ecology; Cork oak; Geographic barrier; Gill and Donsker; Guild; insectivores; Life Sciences; Management; Marine & Freshwater Sciences; Microbial Ecology; Plant Ecology; Quercus suber; sclerophyll forests; woodlands
• ISSN: 1588-2756; 1585-8553; 1588-2756
• DOI: 10.1556/168.2015.16.1.12

The Mediterranean Sea has separated the sclerophyllous forests of southern Europe and northern Africa for millions of years, but its role structuring forest bird assemblages remains unclear. To address this issue we sampled bird assemblages in cork oak woodlands located north and south of the Strait of Gibraltar and compared abundance, diversity, and species and guild assemblage structure between regions. Abundance and diversity patterns were remarkably similar, but dissimilarity analyses of species and guild composition revealed differences in bird assemblage structure between regions. Differences are partly attributable to the effect of the Mediterranean as barrier to the dispersal of forest birds; a few species were unable to colonize North Africa, and many that colonized it remained in sufficient isolation to evolve into distinct taxa. In addition to this divergence of biogeographic genesis, assemblages also differ because in North African cork oak woodlands forest and insectivorous specialist species are less abundant. This dissimilarity could be due to the effect of different exploitation levels present in each region. Managed cork oak woodlands are widespread in the Western Mediterranean, and are valuable because they conciliate economic exploitation with high biodiversity. In North Africa these woodlands are of greater conservation concern because they harbour endemic bird species that give its assemblage a distinct character, cover a smaller area, and are currently under greater pressure from overexploitation. These results highlight the importance to implement management practices that increase resilience and maintain biodiversity value throughout the range of cork oak woodlands.