Reedbeds are important habitats for plants, invertebrates and birds including many rare and vulnerable species. Highest diversity of reedbed faunas is observed at intermediate successional stages thus perturbation in the form of management is necessary in cases we wish to maintain highest possible diversity. . In this study, censuses of birds at 22 census points, visited four times during the breeding season, were used to assess the densities and diversity of passerine birds in reedbeds at the margins of Lake Lesser Prespa. A total of 54 species were recorded in all points but analyses were limited to nine species that are obligate reed-dwellers, at least at some part of their annual circle. The Great Reed Warbler (Acrocephalus arundinaceus) was the most common species, being present in all sites, followed by the Reed Warbler (Acrocephalus scirpaceus). The Great Reed Warbler also showed the highest relative abundance, dominating most of the surveyed sites. The highest densities were calculated for the Bearded Reedling (Panurus biarmicus) in the areas of Agios Achilleios, Vromolimnes and Ekvoli, whereas the Reed Warbler showed the highest population density in Vromolimnes area. Highest species richness was observed in Slatina, Opaya and Platy, while on the other hand Daseri, Agios Nikolaos and Latsista hosted the lowest number of species. In general, results regarding the species present in the reedbed agree with previous studies in the area, but two notable differences were detected: Sedge Warbler (Acrocephalus schoenobaenus) was observed just once in the Slatina site whereas it was far more common in the past and the Marsh warbler (Acrocephalus palustris) was not observed in the Vromolimnes area in the past, but in this study it was found -almost exclusively- in the northern part of the lake. Under the scope of management, it seems that areas of low passerine diversity, dominated by the Great Reed Warbler such as the reedbeds of Pyli as well as parts of the area from Mikrolimni to Bouskani would make reasonably good candidates. Great Reed Warbler abundance will most probably be slightly affected while opportunities for other species to colonize the areas could arise. It would be advisable that cutting in areas of high densities of resident birds such as the Bearded Reedling and Reed Bunting should be avoided, as well as in sites of already high bird diversity such as Slatina, Opaya and Platy. Finally, although the areas of Latsista and Agathoto showed relatively low diversity, the existence of extensive, unfragmented reedbeds still holds conservation value and should remain present in the area.
Bounas, A., 2017. Census of passerine birds in the reedbeds of Lake Mikri Prespa. Report within the framework of the project “LIFE Prespa Waterbirds” (LIFE15 NAT/GR/000936). Society for the Protection of Prespa.
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