Blue-and-black Tanager

The blue-and-black tanager is an average-sized species for its genus, with a mean length of 13 cm (5.1 in) and mass of 18 g (0.63 oz). It shows slight sexual dimorphism, with females being slightly duller than males. Adult males are mainly cobalt blue with a black mask. The wing and tail feathers are black with blue edges. Subadults are mostly gray, but have black wings, tails, and lores. The bill is very short compared to other species of Tangara. The iris is brown, the bill is black, and the feet are wine gray. The blue-and black tanager may be confused with the masked flowerpiercer, but can be distinguished its brown eye, more extensive black on the wing, and shorter and thicker bill. Populations of the subspecies atrocoerulea may also be confused with the golden-naped tanager, but can be distinguished by their blacker back and lack of cinnamon underparts.

Vocalizations. The blue-and-black tanager's calls include a thin, high-pitched tsit, a slightly lower swit, a repeated swit-swit-swit, and a hard SWIT-it. The song is 2–3 second long series of rhythmic, high-pitched notes that begin slow and then speed up into a zieeu-zie-zie-zizizizee trill, given every 15 seconds.

The blue-and-black tanager is found in Bolivia, Colombia, Ecuador, Peru and Venezuela in the northern and central Andes, at elevations of 1,500–3,500 m (4,900–11,500 ft). It inhabits the highest altitude of any Tangara species, and is the only species from the genus that is found near the tree line. It mostly inhabits montane evergreen forest, dwarf forest, and secondary forest. It also inhabits forest edges, vegetation in clearings, and patches of growth near the tree line. It generally stays in the canopy.

The blue-and-black tanager joins large mixed-species flocks while foraging, most often in pairs or groups of 3–6 individuals. Mixed-species flocks can contain up 15 blue-and-black tanagers, and they have been reported as being the nuclear species (species that helps form and maintain a mixed-species flock) in Colombia. It is found more often with Iridosornis or Anisognathus species than other Tangara.

Diet. The blue-and-black tanager feeds on fruit and arthropods, especially fruit from plants in the genus Miconia. It is an active forager that moves through foliage constantly. It forages in all strata, but favors the canopy. Foraging for arthropods occurs by hopping on moss-covered branches and inspecting areas such as the undersides of branches, leaves, moss, and small bromeliads. The species feeds on fruit by reaching out and grabbing them quickly, after which they feed on them while sitting upright.

Breeding. The blue-and-black tanager breeds from February to August. It makes cup nests out of moss and rootlets, lined on the outside with Chusquea bamboo leaves and on the inside with fibers and animal hair. Nests have been recorded in May and June, and are 8 cm (3.1 in) wide and 7 cm (2.8 in) tall on the outside and 6 cm (2.4 in) wide and 3 cm (1.2 in) deep on the inside. Nests have been recorded at heights of 3.8–5 m (12–16 ft) above the ground on small trees. …