The Beryl-spangled Tanager is a typically sized member of the genus Tangara, averaging 17 g (Isler and Isler 1987). The predominant colors are black and green, as reflectd by its specifit epithet of "nigroviridis". Many of the individual feathers are colored both black and green or black and blue, giving the namesake spotted or "spangled" apprearance. Otherwise the plumage pattern of the Beryl-spangled Tanager includes a black mask, black back and predominantly blue wings. Although other tanagers are somewhat similar in appearance, the Beryl-spangled Tanager is the only tanager that has both the spangled pattern as well as a black face mask (Hilty and Brown 1986).
Beryl-spangled Tanagers can be confused with the male Black-capped Tanager (Tangara heinei) and with the Metallic-green Tanager (Tangara labradorides) (Hilty and Brown 1986, Restall et al. 2007). Both of these species have a black crown, and lack the spangles (although the Black-capped Tanager has similar-colored breast streaks) (Restall et al. 2007). The Blue-and-black Tanager (Tangara vassorii) also can resemble the Beryl-spangled Tanager, but Blue-and-black is darker blue and has a smaller black mask that does not extend over its cheeks. The Blue-and-black Tanager also tends to occur at higher elevations, and is the only Tangara that is encountered near treeline (Isler and Isler 1987). In addition, the foraging modes between the Blue-and-black Tanager and the Beryl-spangled Tanager are very different (Isler and Isler 1987). The Beryl-spangled Tanager also is similar in appearance to its close relatives, the Green-naped Tanager (Tangara fucosa) and the Spangle-cheeked Tanager (Tangara dowii). However, these species have more black on their heads, cinnamon buff breasts and bellies, and do not overlap in distribution with the Beryl-spangled Tanager.
Adult male: Appears overall spotted or dappled, with diagnostic "spangles" on the underparts and head (Hilty 2003, Restall et al. 2007). It has a black mask through the eyes with bluish opal, greenish-opal, or yellow-opal (depending on lighting) crown and cheeks (Hilty 2003). The upper back is solid black. Rump is greenish blue (Hilty and Brown 1986). The wings coverts and flight feathers are edged a dark blue, while the sides of its neck, belly, and underparts are black with spots or opalescent blue/green (Hilty 2003). The tail is black, edged with blue. The tips on the feathers of the belly and vent are broader and with a buffy white hue (Fjeldså and Krabbe 1990). The underparts contain a lighter and brighter blue, especially in subspecies lozanoana (Hilty 2003). The plumage on Beryl-spangled Tanagers may appear to be bronzy in some light conditions (Schulenberg et al. 2007).
Adult female: Slightly duller in coloration than males (Fjeldså and Krabbe 1990, Ridgely and Greenfield 2001b, Restall et al. 2007a).
Juveniles: Duller in coloration (Fjeldså and Krabbe 1990). Juveniles (described in Restall et al. 2007a) tend to be a medium brown above (instead of black) with a pale eyebrow. The light brown reaches the nape and runs around the auriculars. The wing coverts are a fringed pale buffy, while the belly is a spangled brown and buffy with a hint of a pale blue (Restall et al. 2007a).
Nestlings/downy young: No Information.
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). Although a subadult/juvenile plumage is described for Tangara nigroviridis, more specific information on molt and its timing is not available for this species.
Bill: maxilla black, mandible blue-gray
Tarsi and toes: gray, brownish gray
Data from specimens in the Louisiana State University Museum of Natural Science.
Total length: 12 cm (Isler and Isler 1987), 12.7 cm (Hilty 2003), 13 cm (Hilty and Brown 1986), 13.5 cm (Ridgely and Greenfield 2001)
Mass, both sexes: 17 g (14-19.5 g; n = 34; Isler and Isler 1987).
Mass, both sexes, Serranía Bella Vista, Bolivia: 15.7 g ± 0.9 (n = 11; Naoki 2003).
Mass, both sexes, Mindo, Ecuador: 17.9 ± 1.0 (n = 12; Naoki 2003, 2007).