Blue-and-yellow tanager  (Thraupis bonariensis)

Classified as Least Concern (LC) on the IUCN Red List (1).

The blue-and-yellow tanager is one of the most colourful small birds within its range (3) (4) and the most boldly coloured of the Thraupis species (2). However, contrary to one of its Spanish names, translated as “seven-colours”, the species does not quite have seven colours (4) and, unlike in many tanager species (5), only the male is brightly coloured (2). The male blue-and-yellow tanager is a gaudy bird, with a light blue head and throat, black back, collar and sides of the chest, a black ‘mask’ from the base of the beak to behind the eye, and a bright orange-yellow breast and rump. The wings and tail are black, edged with blue (2) (3) (4). The female is much duller and lighter in colour (2) (3) (4), being mostly greyish-brown, with a dusky blue tinge on the head and a yellowish-buff rump (2).

There are currently considered to be four subspecies of blue-and-yellow tanager: Thraupis bonariensis bonariensis, Thraupis bonariensis composita, Thraupis bonariensis darwinii and Thraupis bonariensis schulzei (6). The female T. b. bonariensis has less blue on the head than the female T. b. composita, while the female of the smaller T. b. darwinii has considerably more blue on the head, and the male of this subspecies has an olive-green rather than black back (2).

Thraupis tanagers are generally quite active, conspicuous and noisy birds. The song of the blue-and-yellow tanager is a series of four to six sweet, doubled notes, “sweé-sur, sweé-sur, sweé-sur”, and lacks the squeaky quality of other Thraupis species (2).

The blue-and-yellow tanager is found in South America, in Argentina, Brazil, Chile, Peru, Ecuador, Bolivia, Paraguay and Uruguay (2) (7). T. b. bonariensis occurs in the southern lowlands of South America, T. b. composita in eastern Bolivia, and T. b. darwinii from Ecuador to northern Chile and Bolivia (2). No information is available on the range of T. b. schulzei.

This species typically inhabits Andean slopes and arid valleys (2), at elevations of up to around 4,000 metres (3), although it also occurs in lowlands in southern South America (2). It may be found in light woodland, scrub, gardens, agricultural and urban areas, and favours semi-arid, fairly open terrain (2) (3) (4).

The blue-and-yellow tanager occurs in pairs or small groups (2), and may feed on fruits, insects and sometimes leaves (2) (8). The nest is cup-shaped and built in bushes or in the crown of tall trees, and may be lined with grass, dry vegetation and feathers. Little information is available on the breeding behaviour of the blue-and-yellow tanager, though it has been reported to lay around two to three eggs, which are white in colour, with a slight greenish-blue tint and coloured blotches or spots (3) (4). Incubation lasts around 13 days, and the breeding pair may lay more than one clutch in a season (4).

The blue-and-yellow tanager is reported to be a migratory species (9), although there is a lack of detailed information on its movements. Some report it to undergo regional movements in response to food availability and climate (4).

No specific threats have been reported for this species, although some suggest that its bright colouration has led to it being trapped as a cage bird (8). However, the blue-and-yellow tanager still has a large range and is believed to be fairly common (7).

There are no known specific conservation measures currently in place for the blue-and-yellow tanager. Information on the species is relatively lacking and so it may benefit from further research.

View information on this species at the UNEP World Conservation Monitoring Centre.

To find out more about the blue-and-yellow tanager and about other South American birds, see:

• BirdLife International:
  http://www.birdlife.org/datazone/species/index.html?action=SpcHTMDetails.asp&sid=9321&m=0
• Ridgely, R.S. and Tudor, G. (1989) The Birds of South America: The Oscine Passerines. Volume I. University of Texas Press, Austin, Texas.
• Aves de Chile:
  http://www.avesdechile.cl/