Feeding ecology of the Great White Pelican (Pelecanus onocrotalus) nesting at Lake Mikri Prespa (northwestern Greece)

The feeding ecology of Great \Vhite Pelicans (Pelecanus onocrotalus) nesting at Lake Mikri Prespa was studied during 1984, 1985 and 1991. Chick diets consisted mainly of Alburnus spp. Prey length consumed by chicks, feeding frequencies and the distribution of meals delivered to chicks during the day varied throughout the rearing period. The investigation of the foraging sites revealed for the first time the utilization of Lakes Mikri and Megali Prespa, confirmed the regular use of the neighboring Lakes Chimaditis and Kastorias, proved the use of the Axios Delta (149 km from the colony) and provides evidence for the use of Lake Kerkini (182.5 km distance). The impact of Great White Pelicans on commercial fisheries of Mikri Prespa was slight; only 4% of the annual fish yield, while negligible for Lake Megali Prespa. A temporal pattern in the exploitation of the above mentioned sites was observed during the breeding season. Some conservation measures are recommended.