VOLUME 33 - N. 2

Abstract:

Waders (Charadrii) were counted weekly at six Greek wetlands during spring and autumn of the years 1996, 1997 and 1998 (161 counts in total). The aim of this research was to study the diversity, abundance and phenology of waders at the major coastal wetlands of Greece. Altogether 40 species were recorded. Among these, 15 were qualifed as common migrants (present in all wetlands in both seasons), 16 as moderately common migrants (present in more than three wetlands but not in both seasons), 6 as rare migrants (between two and ten records during the study) and three as very rare (with just one record). The species diversity was very similar between the autumn (38 species) and spring migrations (37). However, the abundance of waders overall, was higher during the spring passage. The most abundant species during spring were the Ruff Philomachus pugnax followed by the Curlew Sandpiper Calidris ferruginea and the Dunlin Calidris alpina. During autumn the Redshank Tringa totanus followed by the Little Stint Calidris minuta and the Kentish Plover Charadrius alexandrinus were the most abundant species. The abundance of 16 species was much higher in spring while the abundance of nine was much higher in autumn, indicating that these species use different migration routes depending on the season. It is most probable that weather conditions affect the arrival and departure dates of migrating waders. The interannual differences regarding the abundance of migrating waders could probably also be explained by weather conditions. The understanding of the abundance of waders, their diversity and migration phenology contributes to the conservation and management of Greek coastal wetlands, which are much affected by habitat degradation and human disturbance.