Results of the January 2015 waterbird census in Slovenia

In 2015, the International Waterbird Census (IWC) was carried out in Slovenia on 17 and 18 Jan. Waterbirds were counted on all larger rivers, along the entire Slovenian Coastland and on most of the major standing waters in the country. During the census, in which 276 observers took part, 409 sections of the rivers and coastal sea with a total length of 1385.8 km and 224 other localities (172 standing waters and 52 streams) were surveyed. Altogether, 46,425 waterbirds of 57 species were counted. This is one of the lowest numbers of waterbirds recorded during the 19 years of IWC in Slovenia. The highest numbers of waterbirds were counted in the Drava count area, i.e. 17,014 individuals (36.7% of all waterbirds in Slovenia). By far the most numerous species was Mallard Anas platyrhynchos (45.9% of all waterbirds), followed by Coot Fulica atra (8.4% of all waterbirds), Blackheaded Gull Chroicocephalus ridibundus (7.5% of all waterbirds), Cormorant Phalacrocorax carbo (5.7% of all waterbirds) and Mute Swan Cygnus olor (4.6% of all waterbirds). The number of 1000 counted individuals was also surpassed by Tufted Duck Aythya fuligula, Yellow-legged Gull Larus michahellis and Teal An. crecca. Among the rarer recorded species, the Cattle Egret Bubulcus ibis (registered only for the third time during the IWC) and Lesser Black-backed Gull Larus fuscus (registered only for the fourth time during the IWC) deserve special mention. Also, Ruddy Shelduck Tadorna ferruginea was recorded for the fourth time during the IWC, but the individual observed was classified to category E (introduced species without self-sustaining populations, escapees from captivity). Numbers of the following species were the highest so far recorded during the IWC: Greylag Goose Anser anser, Muscovy Duck Cairina moschata, Shoveler An. clypeata, Goosander Mergus merganser and Common Sandpiper Actitis hypoleucos. The number of Redbreasted Mergansers M. serrator was the lowest so far recorded during the IWC.