New record of aberrant plumage in Blue-black Grassquit (Volatinia jacarina Linnaeus, 1766, aves: Emberizidae).

567 The Blue-black Grassquit Volatinia jacarina (Linnaeus, 1766), popularly known in Brazil as “tiziu”, is an inhabitant of open areas, and also common near cities (MarcondesMachado, 1988). The most remarkable characteristic of this species is the male blackish blue iridescent plumage, especially during the reproductive season (Queiroz, 2008). Nevertheless, variation in this colouration pattern is not uncommon, being noted mainly in captive specimens, with few observations in wild individuals (Piacentini, 2001). Herein, we report a new record of aberrant plumage colouration of the wild Volatinia jacarina from Mato Grosso state, Brazil. Nine individuals of V. jacarina were mist netted between 17-22 November 2009 during an environmental impact study in “El Dourado” farm (52° 14’ 12” W and 15° 32’ 01” S), municipality of Barra do Garças. Of these, one individual presented a different plumage colouration that consisted of very clear almost yellow across the head and many dorsal clear spots (Figure 1). Following the plumage colour classification proposed by Nemésio (1999) we describe this individual as “arlequins” colouration. This class is the most common variation form and consists in total suppression of melanin in the bird’s head (Nemésio, 1999; Piacentini, 2001). The variation of plumage colouration can be explained by some factors such as exogenous (e.g. food) or endogenous (e.g. relative mating) (Nemésio, 2001). Some studies relating structural New record of aberrant plumage in Blue-black Grassquit (Volatinia jacarina Linnaeus, 1766, aves: Emberizidae)