Arkadiusz Sikora, Dawid Cząstkiewicz
Ornis Polonica 2014, 55: 264–278
https://doi.org/10.12657/ornis.2014.4.3
Abstract: This study analyses records of the Great White Egret Ardea alba in Warmia and Masuria (NE Poland) in 1989–2012. Most data come from accidental observations of non-breeding birds. In 1989–2000 the Great White Egret was recorded at only 10 sites. However, after several years its numbers started to increase dynamically, and the species appeared in many new places. The peak number was recorded in 2011–2012, when the species was found in 117 localities of all 161 recorded in 1989–2012. In spring and summer the Great Egret was observed relatively rarely (11% of all records in each season, and 3% and 5% of all individuals, respectively). Most birds were found in autumn (76% of all records and 91% of individuals). The numbers reached the highest levels from late September to mid-October. Maximum numbers of 380 individuals were found near Sątopy-Samulewo (Bisztynek Commune) and 180 individuals near Kwiecewa (Świątki Commune). In December–February 2% of all observations were made. The species was found the most often at lakes (37% of 151 localities) and fish-ponds (25%). Great White Egrets were often accompanied by Grey Herons A. cinerea (37% of records concerned both species). During the majority of the year the Grey Heron was more abundant than the Great White Egret, but the opposite was found in August–October. In 2008 the first nesting attempt was reported from polder near Sątopy-Samulewo. At the same site some probably breeding birds were observed also in 2010 and 2012, as well as 12 pairs bred in 2013. The second breeding locality hosting 8 pairs was detected in 2012 at Lake Gołdapiwo. The expansion of the Great White Egret in Warmia and Masuria corresponds with the dynamic growth of the species European population and changes in its range.
Keywords: Ardea alba, expansion, Great White Egret, Warmia and Masuria
