Cygnus olor immutablis in Poland

Abstract

Between 1979-89 the "Polish Swan” was recorded breeding in Poland at over 60 sites. Its distribution appeared uneven, perhaps due to incomplete cover. The proportion of pairs producing white cygnets varied from 3% to 17%, and the frequency of white young from 2% to 9%. At moulting areas, the proportion of adult “Polish Swan” ranged from 0% to 11%, but on winter quarters, it was less common, ranging from 1% to 6%. No significant differences were found in the proportion of white young in broods between the birds living in Poland and in Denmark. The proportion of “Polish Swan” in the Mute Swan population in Poland is compared with data from other European countries.