The Chestnut-backed Tanager is a very colorful species of bird in the family Thraupidae, the New World tanagers. It is found in southern Brazil, north-eastern Argentina, eastern Paraguay, and Uruguay. It is closely related to the rarer Black-backed Tanager, and females of the two species are indistinguishable. This bird is characterized by its green breast, and chestnut colored back.

The Chestnut-backed Tanager has a black bill, a stout body, and a long tail. It measures about 16 cm (6.3 in) in length and weighs about 28 to 41 g (0.99 to 1.45 oz). It has three subspecies, which differ in their plumage, but all the males have a red face and crown and green to blue-green upperparts. The males’ lower breasts are red and their bellies yellowish with green streaks, though the size and shape of the red vary. The females have a greenish cap, blue malars with a yellow edge, and a blue throat with a thin red band below it.

The Chestnut-backed Tanager lives in open wooded areas, especially with oaks, acacias, and eucalyptus. It is uncommon and often inconspicuous, as it forages mainly at middle to upper levels of the forest1. It feeds mostly on ants and termites, which it catches on the wing or pecks from tunnels and bark. It also eats other insects, seeds, nuts, berries, eggs, and small animals. It sometimes visits bird feeders, where it may compete with other birds for food. It has a loud and harsh voice, and can produce a variety of sounds, including imitations of other birds, animals, and human noises. It has a distinctive chuckling call note, and a song that resembles a robin’s but is clearer and less nasal.

The Chestnut-backed Tanager breeds from March to June, depending on the location. It builds a cup-shaped nest of twigs, moss, and mud, usually in a hollow of a eucalyptus tree. The female lays 3 to 6 eggs, which are greenish or bluish with brown spots. The male helps to incubate the eggs and feed the young. The chicks fledge after about 16 days, and stay with their parents for another month or so.

The Chestnut-backed Tanager is a resident bird that does not migrate. It is not threatened by extinction, and has a large and stable population. However, it may face some threats from habitat loss, fragmentation, and degradation, as well as from predators, parasites, and diseases. Therefore, it is important to protect and conserve its natural environment, and to appreciate its beauty and role in the ecosystem.