Hydrobiologia 351: 143–155, 1997. 143 A. J. Crivelli & G. Catsadorakis (eds), Lake Prespa, Northwestern Greece. c 1997 Kluwer Academic Publishers. Printed in Belgium. Breeding birds from reedbeds to alpine meadows G. Catsadorakis Society for the Protection of Prespa, 530 77 Agios Germanos, Greece Key words: alpine birds, bird–habitat relationships, farmland birds, Greece, passerines, Prespa, reedbed birds, woodland birds Abstract The fauna of passerines (Passeriformes) and other bird families (Galliformes, Columbiformes, Cuculiformes, Coraciiformes and Piciformes) censused with similar methods, was examined; 132 species of the above families have been observed in the Prespa area. Of these, 19 non-passerines and 77 passerines breed. The composition of avian communities during the breeding season and the relative abundance of their species were studied in nine habitats, namely: reedbeds, croplands, sparse woodland on abandoned fields, hop-hornbeamwoodland, oak-juniper shrubland, oak forest, beech forest, mixed deciduous forest and alpine grasslands. Six species made up the avifauna of reedbeds, the Great Reed Warbler being the most widespread. There were nine typical farmland species but Corn Bunting, Black-headed Bunting and Red-backed Shrike comprised more than 65% of the total. The most widespread and numerous species in the National Park were the typical species of temperate forests such as Blue Tit, Jay, Chaffinch, Blackcap, Chiffchaff, Marsh Tit and Great Tit. Skylark, Whinchatand Ortolan Bunting were the commonest species above the tree line. Very few similarities existed between the avifaunas of croplands, alpine grasslands and reedbeds. Correspondence Analysis was used to analyse the avifaunistic composition of each one of the six woodland habitats along with the floristic composition, seven abiotic features and 21 measures of vegetation structure. The most diverse avifauna was that of the mixed deciduous forest which had the highest horizontal and vertical structural heterogeneity. The avifauna of Juniper shrubland differed from those of all other types of woodland studied. The degree of human influence upon the vegetational features of this habitat is not easy to define, but the existence of endemic plant and animal taxa and relict species of plants and birds suggests that the differences can be attributed not only to its vegetational characteristics but may also have a paleoecological background. Introduction One of the main values of Prespa National Park is its habitat variety. This is due to its geographical position at the limits of the Mediterranean area, its geomor- phology, its topography, the great altitudinal differ- ences within the area and its geologic history (Pavlides, 1985). The activities of man for hundreds of years have had a differential impact upon each of these habitats, sometimes leading to an increase in biodiversity and sometimes to a decrease. Because of their high mobility and colonisation abilities birds are not the best indica- tors of habitat changes and usually it is not easy to draw firm conclusions on the relation between the features of a habitat and its birds from analysing their patterns of distribution and abundance, in places even slightly modified by man. On the other hand, in Greece very few studies of the habitat relations of birds have been made. Even for areas that are relatively well known ornithologically, only lists of species exist with indi- cations of breeding and migration status and such lists often contain errors. Until recently this was also the situation for Prespa. The present paper summarizes part of the results from the only relatively long-term study of a passerine community in Greece, namely that of Prespa National Park (Catsadorakis, 1989). This study was carried out from 1983 to 1989. The present paper tries to approach the biodiversity of Prespa via its diverse fauna of birds. Its aim is to contribute to our understanding of the distribution and abundance