The Ruby-crowned Tanager (Tachyphonus coronatus) is a medium sized Neotropical tanager, and like most species in the genus Tachyphonus, males are primarily black with white underwing coverts, while females are dull olive or brown (Sick 1993, Ridgely and Tudor 2009). Both sexes show a pale blue color on the lower mandible (Ridgely and Tudor 2009). They are most similar to its sister species the White-lined Tanager (Tachyphonus rufus), and the closely related Red-shouldered Tanager (Tachyphonus phoenicius), which the former having an overlapping range with the Ruby-crowned Tanager (Isler and Isler 1987, Hilty 2011, Burns et al. 2014).
The Ruby-crowned Tanager sister species, confirmed by molecular systematics, is the White-lined Tanager (Tachyphonus rufus), and these two species in turn are sister to the Red-shouldered Tanager (Tachyphonus phoenicius); these species are not only molecularly similar, but also morphologically (Hilty 2011, Burns et al. 2014). The Ruby-crowned Tanager and White-lined Tanagers have similar voices, behaviors, and plumage but the Ruby-crowned Tanager is less stocky, and they are probably best identified by their accompanying female (Ridgely and Tudor 1989, Sick 1993). The female Ruby-crowned Tanager is duskier, with the head and breast grayer and the upper breast lightly streaked, whereas the female White-lined Tanager is uniformly rufous-brown (Sick 1993). Both species have been found in western São Paulo in southeastern Brazil (Sick 1993). However, habitat preferences between the two differ with the White-lined Tanagers not along edges, but within secondary forests, gallery forests, tropical lowland evergreen forests, and second-growth scrub (Parker et al. 1996). The Ruby-crowned Tanager does not overlap in distribution with the Red-shouldered Tanager, but they would be easiest to discriminate via female plumage. The male Ruby-crowned Tanager has similar black and glossy plumage to the Shiny Cowbird (Molothrus bonariensis) and Screaming Cowbird (M. rufoaxillaris), however the Ruby-crowned Tanager has pale blue at the base of the lower mandible, white under wing coverts, a scarlet crown when visible, and behavioral differences (Ridgely and Tudor 1989). The female Ruby-crowned Tanager resembles the female Red-crowned Ant-Tanager (Habia rubica) but the latter is less olive-colored, has flame-like breast streaking, and an orange-red crown stripe (Ridgely and Tudor 1989). The female Red-crowned Tanager may also be confused with the female Flame-crested Tanager (Tachyphonus cristatus), which is smaller in size and differs in arboreal behaviors (Sick 1993, Ridgely & Tudor 1989).
Adult males at rest are entirely a slick black-blue (Meyer de Schauensee 1970). White underwing coverts are shown in displays or flight, and they have a scarlet patch on the center of the crown that is usually hidden unless the crest is raised (Mitchell 1957, Isler and Isler 1987, Sick 1993). Adult females have a reddish-brown upper body which is brightest on the rump and tail, with grayer heads, whitish chins, a thin eye-ring with relatively pale lores, with the breast and flanks brownish streaked dusky (Isler and Isler 1987, Ridgely and Tudor 1989). The flight feather are dusky, edged rufous (Hilty 2011). The rufous underparts of some females have been noted to have less contrast with the upperparts (Isler and Isler 1987). Although the sexes are obviously dichromatic, they are likely more different than we can perceive, for both refract UV light and this coloration is dimorphic (Burns and Shultz 2012). Immature birds are more similar to the adult female, with immature males with black mottling. Subadult males can retain this mixture of a black and brown body feathers for some time, and this mottling can occur almost anywhere in the plummage (Sick 1993, Hilty 2011).
Tanagers that have been studied have a Complex Basic Strategy or Complex Alternative Strategy, and the preformative molt in Tachyphonus is partial in nature (Ryder and Wolfe 2009). After formative plumage is attained, most tanagers only molt once a year (Isler and Isler 1987). This prebasic molt likely occurs after the breeding season (Isler and Isler 1987, Ryder and Wolfe 2009). Many species have been found to breed in subadult plumage (Isler and Isler 1987). A young male was in molt in April, and an adult male was near the end of wing molt in March (Willis and Oniki 2002).
The males upper mandible is black, the lower mandible blue-gray with a black tip, the iris is dark-brown, and the legs horn-gray to dark-gray to black (Belton 1985, Hilty 2011). Females have the tarsus and mandibles dark gray (Belton 1985).
The length is 16-18 cm, and they are typically 26-29 g (Short 1971, Belton 1985, Isler and Isler 1987, Ridgely and Tudor 1989, Sick 1993). Weights from 33 unsexed birds from Brazil had an average of 29.3 g, range 26.0-33.1 g (Oiniki 1981, cited in Dunning 2008). Four individuals from Brazil weighed 29.5 g (male), 20.5 g (female), and unsexed birds of 26.0 g and 26.5 g (Reinert et al. 1996). Birds from Argentina (Capllonch et al. 2015) had an average weight of 25.6 g (23.0-28.0; n=5), length of 16.4 cm (16-16.9; n=6), culmen of 15 mm (14-16; n=6), wing length of 7.9 cm (7.5-8.2; n=6), and tail length of 7.4 cm (6.6-8.3; n=6). The gape width of 10 individuals from the Museum of Zoology at São Paulo was 9.14 mm (Côrtes et al. 2009). Further measurements are reported in Table 1.
Table 1. Measurements of Adults (Roos 2002)
Total Length (cm)
Right Wing (cm)
Left Wing (cm)
Right Tarsus (cm)
Left Tarsus (cm)
Tail Length (cm)