Trichothraupis griseonota, Cavarzere & Costa & Cabanne & Trujillo-Arias & Marcondes & Silveira, 2024

Cavarzere, Vagner, Costa, Thiago Vernaschi V., Cabanne, Gustavo S., Trujillo-Arias, Natalia, Marcondes, Rafael S. & Silveira, Luís F., 2024, A new species of tanager (Aves: Thraupidae) from the Eastern slopes of the Andes, Zootaxa 5468 (3), pp. 541-556 : 547-549

Trichothraupis griseonota sp. nov.

Proposed vernacular names: Andean Black-goggled Tanager (English); tiê-de-topete-andino (Portuguese); Frutero corona amarilla andino (Spanish).

Holotype. MACN 8979 a, Male. BOLIVIA, Buenavista , Santa Cruz, 30 July 1916, J. Steinbach leg., 450 m.

Paratypes. MACN 72807 , Male. BOLIVIA, Pedernal, Chuquisaca, Tomina , 08 October 2011, G. S. Cabanne leg., 1450 m asl . Habitat type: Tucumano-Boliviano Forest . Mist-netted by GSC. Iris: brown, bill black, mandible light gray, feet gray. Tissue sample MACNCTOR 6286. Weight : 21.75 g, skull ossification 100 %, bursa 3x 3 mm, testis 4x 3 mm . MACN 8979 b, Female. BOLIVIA, Buenavista , Santa Cruz, 30 July 1916, J. Steinbach leg., 450 m.

Etymology. From Latin griseo (gray) and nota (mark), highlighting one of the most distinctive plumage characters of the new species.

Diagnosis. Four fixed plumage traits and one morphometric trait diagnose Trichothraupis griseonota from its sister species, T. melanops . The first and most noteworthy is the black facial mask. In the new species, it includes the auricular region ( Fig. 1 ; Fig. S3 ), whereas in T. melanops this mask is only a narrow line behind the eye, not reaching the auriculars. In a few Atlantic specimens (AMNH 774505, LSUMZ 59405, MZUSP 27851) there is some black in the auriculars, but in those cases, it is mixed with green, producing a mottled appearance, unlike the homogeneous black in T. griseonota . A second diagnostic character is the paler underparts of adult males and females. This is especially evident in the undertail coverts, which are a cream color to buff-yellow in T. griseonota , versus cinnamon in T. melanops , and in the chest, in which both species have a more orange tone than in the belly, but less distinctly so in the new species, where the color of the chest is more buff-yellow, versus buff in T. melanops ( Fig. 1 ). Adult females of T. griseonota are also somewhat paler in the underparts than in T. melanops , but the difference is not as pronounced as in males, and sexual dimorphism of plumage color in the underparts is more evident in T. griseonota than in T. melanops . The third plumage characteristic is the color of the back of adult males, which is greyer in T. griseonota , versus being more greenish-olive in T. melanops ( Fig. 1 ; Fig. S3 ). The last character in which the two species differ is the breast coloration of females, which is subtly but consistently darker in Atlantic populations ( Fig. 2 ). Trichothraupis griseonota also has significantly shorter tarsi compared to T. melanops ( Fig. 4 ).

Description of holotype. The front, loral, superciliary, and auricular regions are black; the nape is also black, slightly streaked above The throat, chest, belly, and undertail coverts are pale brown, light olive-brown in the lateral chest. The crown to the nape is yellow. The back is dark olive grey (M5Y-3/2). The upper wing coverts, remiges, and rectrices are dark brown, with white underwing coverts. The base of primaries 2–7 shows a white middle band occupying the inner web of the feather, while the two outer primary feathers do not have white bands. The white band also occurs on the secondary feathers. The maxilla is greenish-black, while the mandible is black at the base. The feet are olive-brown. Total length: 161 mm. Bill length: 12.24 mm, 8.99 mm from nares to the tip; bill width 4.40 mm, height 5.34 mm. Wing chord (unflattened): 83.2 mm; tarsus length: 17.25, and tail 78.55 mm.

Description of the female paratype. The forehead, nape, loral, crown, superciliary, and auricular region are olive. The throat, breast, and belly are pale brown. The lateral breast is light olive brown, and the undertail coverts are like the lateral breast. The back is grayish-olive, while the upper wing coverts, flight feathers, and tail are dark brown, and underwing coverts are white. The bases of the primaries (2–7) and the secondaries have a white middle band on the inner web of the feather, lacking in the two outer primary feathers. The feet are olive brown. Total length: 168 mm. Bill length: 11.76 mm. Bill length from nares to the tip: 9.00 mm, bill width 5.06 mm, bill height 5.75 mm. Wing chord (unflattened): 79.56 mm, tarsus 17.90 mm, and tail length 79.84 mm. The bill is greenish-black, and the mandible is black at the base, with a light brownish-gray tip.

Distribution. Trichothraupis griseonota is restricted to the eastern slope of the Andes of central and southern Peru, Bolivia, and northwestern Argentina ( Fig. 5 ). It inhabits the Seasonal Dry Tucumano-Boliviano Forests which are confined to the northwestern Argentinean Andean forests and foothills north to central and southern Bolivia. The species also occurs along a narrow strip of Yungas Forests in northern Bolivia and Peru, at the base of the Andes. These montane forests exhibit higher moisture levels compared to the Tucumano-Boliviano Forests.

Figures

FIGURE 1. Dorsal (a), ventral (b), and lateral (c) views of males of the Atlantic (LSUMZ 53115, Itapetininga, Brazil; above) and Andean (LSUMZ 171459, Samipata, Bolivia; below) populations of Trichothraupis melanops.

FIGURE 2. Dorsal (a) and ventral (b) views of females of the Atlantic (LSUMZ 53117, Salesópolis, Brazil; above) and Andean (LSUMZ 90992, Serranía Bellavista, Bolivia; below) populations of Trichothraupis melanops.

FIGURE 3. Principal Component Analysis of Atlantic Forest (orange) and Andean (green) populations of Trichothraupis melanops. No morphometric segregation was found for males (A) or females (B).

FIGURE 4. Trichothraupis melanops (above) and T. griseonota sp. nov. (below). Plate by Eduardo Brettas.

FIGURE 5. Distribution of Trichothraupis melanops (orange) and T. griseonota sp. nov. (green) in South America. Squares represent museum specimens and circles are recordings. A diamond indicates the type locality of T. griseonota; there is no type locality for T. melanops. South America is represented in the inset.