FOOD PREFERENCES AND DIETARY OVERLAP BY TERRESTRIAL SNAILS IN LOGOS AREA (EDESSA, MACEDONIA, NORTHERN GREECE)

Abstract

Among the five coexisting species of snail in Edessa (N. Greece), Bradybaena fruticum and Helix lucorum dominated in density and biomass in comparison with Xeropicta arenosa, Monacha cartusiana and Cepaea vindobonensis. Resting places of each species in relation to plant cover and diet preferences are examined seasonally and throughout a year. Discriminant analysis for the annual data showed that 83% of the snail group species could be differentiated by the plants on which they were attached. Each snail species was usually found sitting on one of the most abundant plants. Cepaea preferred to sit on and eat senescent material even in spring time and Bradybaena green material. In spring, the snails did not consume plant material in proportion to the occurrence of those plants but they usually did so in summer and in autumn. Hedera helix was not consumed even when it was abundant. In spring and autumn the snails had consumed plants to which they were found attached, but in summer they did not.