Analysis of two cases of potential plumage colour aberrations in the House Sparrow Passer domesticus L., 1758

Abstract

Two cases of possible plumage colour aberrations in the House Sparrow Passer domesticus L., 1758 in Spain are discussed. These two examples highlight the difficulties in correctly identifying plumage colour aberrations in birds. A correct identification of these aberrant individuals as well as information on their number and distribution would certainly expand our understanding of the factors determining their occurrence in natural bird populations.