The Dipper Cinclus cinclus in Sicily
SARÀ M., SORCI G., SARÀ G. and CUSIMANO CAROLLO T.Abstract:
The distribution and density of the Dipper (Cincl us cinclus) in Sicily has been studied from existing records over the main island's catchments. The species has been decreasing in number over the past 40 years and it is now restricted to a few, isolated and residual montane areas and can be considered on the verge of extinction. Mean density in these areas (6.3 pairs/lO kms) matches the mean values reported for continental Europe, but the decrease in range and the isolation of the populations follow the progressive drying and transformation undergone by the Sicilian basins as a result of anthropogenic and rnetereological factors. The Dipper's presence is strongly tied to permanent streams, but its density, assessed by multiple regression analysis, is related to stream bed morphology: gradient, substrate granulometry, water temperature and depth. The species breeds along stretches of high quality water where, according to the E.B.1. method, the fauna is richer in macroinvertebrate than elsewhere.