THE DIET OF DALMATIAN PELICANS (PELECANUS-CRISPUS) BREEDING AT LAKE MIKRI PRESPA NATIONAL-PARK, GREECE

The diet of breeding Dalmatian pelicans (Pelecanus crispus) was studie d at Lake Mikri Prespa National Park, Greece during May and June of 19 92, 1993, 1995, and 1996. Analyses of chicks' regurgitates obtained fr om the Mikri Prespa nesting colony showed that Dalmatian pelicans pred ominantly consumed Chalcalburnus belvica, an endemic fish restricted t o lakes Mikri and Megali Prespa, i.e., they exploited exclusively loca l fish resources during breeding. We found within-breeding season, as well as annual variation in mean weight and length of the fish capture d, but no year-to-year variation in mean weight of regurgitates (about 384 g). C. belvica was the most abundant fish in the total commercial catch from the Prespa lakes. Hatching of Dalmatian pelican eggs at Mi kri Prespa Lake coincided with schooling and spawning of C. belvica. T he prolonged period of multiple spawning (until August) provided pelic ans with a continuous food supply throughout breeding. This coincidenc e, combined with the abundance and availability of C. belvica, may exp lain the exclusive choice of this prey from more than 20 fish species found in the Prespa Lakes. We may, therefore, relate successful breedi ng and possible choice of nesting site of Dalmatian pelicans to the pr esence and availability of C. belvica.