Breeding bird assemblages of eastern Mediterranean shrublands: composition, organisation and patterns of diversity

Abstract

The patterns of α-diversity and the structure and organisation of breeding bird assemblages were studied in four vegetation stages (characteristic of Mediterranean shrublands) on an eastern Mediterranean island (Crete, Greece): low phrygana, tall phrygana, low maquis and tall maquis. Phrygana differed significantly from maquis, in regard to the community metrics, composition and the homogeneity of bird assemblages. Moreover, detrended correspondence analysis ordered the census plots along a continuum of increasing vegetation height. On the other hand, within-maquis differences were few, while no significant differences were found within phrygana stages. Based upon the observed patterns, we recognise three vegetation groups: (1) phrygana, with low α-diversity and abundance and homogenous bird assemblages; (2) low maquis with relatively high α-diversity and heterogenous bird assemblages; and (3) tall maquis with relatively high α-diversity and heterogenous assemblages in which “woodland” bird species contribution is prominent.