A case of partial leucism in the Blue-black Grassquit (Volatinia jacarina) from Venezuela

Abstract

Reports of plumage aberrations in wild birds, as well as their distribution and frequency, are important because of their implications in bird conservation, since they are likely associated with environmental factors (e.g. contamination), population genetics, population size (e.g. endogamy) or nutrition (e.g. resource scarcity). This article documents a case of plumage aberration in a Blue-black Grassquit (Volatinia jacarina) female individual sighted and photographed in a suburban area of northern Venezuela. The aberrant individual was mostly (> 70%) white, except for the crown, wings (primary feathers and its coverts), crisum, and tail. The white plumage showed a symmetrical distribution pattern. The eyes, tarsi and beak had normal pigmentation. Based on literature consulted and a dichotomous key to identify pigmentary abnormalities, the plumage aberration corresponds to partial leucism. This record constitutes the first case of leucism for the Blue-black Grassquit in Venezuela, and adds to other observations of plumage aberration in wild birds of the Neotropical area.