Silvery Tanagers are an average-sized member of the large genus Tangara. Unlike most species in this genus, the Silvery Tanager displays marked sexual dichromatism. The male is mainly black with a shiny light gray mantle and flanks. The auriculars and throat are coppery orange. In contrast, the females are primarily greenish with a buffy brown nape, crown, ear coverts, and throat.
The shiny light gray mantle against the overall black plumage is a distinctive feature of the Silvery Tanager. The Green-throated Tanager (Tangara argyrofenges) has a similar pattern to the Silvery Tanager, but in male Green-throated the mantle, rump, and flanks are straw colored, and the throat is opalescent green, not coppery (Ridgely and Tudor 2009). Female Green-throated Tanagers can be distinguished from female Silvery Tanagers in that their yellower mantle and flanks, and by the silvery green throat (Ridgely and Tudor 2009). In addition, the Green-throated and Silvery tanagers have only local overlap, in some regions of northern Peru (Ridgely and Tudor 2009). Another similar species is the Black-capped Tanager (Tangara heinei), which has a gray mantle, however; this species differs in that it has gray underparts and a green throat (Ridgely and Tudor 2009) and also does not overlap in distribution with the Silvery Tanager (Ridgely and Greenfield 2001, Restall et al. 2007).
Adults are sexually dichromatic.
Adult male: Overall black and and silvery blue-gray. Crown and lores black. The auriculars to the chin, throat, and lower cheeks are orange buffy (Restall et al. 2007). The mantle to the uppertail-coverts are pale turquoise. Sides of the neck, and the breast and belly, are black (Restall et al. 2007). The flanks and the sides of the breast are turquoise (Restall et all. 2007). The edges of the wings and of the rectrices are dark bluish gray (Ridgely and Tudor 1989).
Adult female: An overall softer green with a face pattern that is similar to the males but paler in color (Restall et al. 2007). The crown, lores, nape, and the sides of the neck are buffy brown (Isler and Isler 1987, Restall et al. 2007). The breast and belly are gray; flanks are green. The wings and tail are darker than the rest of the body and there are bluish fringes on the remiges (Restall et. al 2007).
In general, most tanagers only molt once a year (Isler and Isler 1987), and this prebasic molt likely occurs afterthe breeding season (Isler and Isler 1987, Ryder and Wolfe 2009). However, many species have been found to breed in subadult plumage (Isler and Isler 1987). In many species of Tangara, the preformative molt is partial (Ryder and Wolfe 2009). More specific data on molt is not available for Tangara viridicollis.
Iris: brown (Restall et al. 2007)
Bill: black (Restall et al. 2007)
Tarsi and toes: gray (Restall et al. 2007)
Total length: 12.5-13 cm (Isler and Isler 1987, Restall et al. 2007)
Mass, both sexes: mean 21 g (range 18.1 g-24 g; n = 23; Isler and Isler 1987)