Brown-backed Mockingbird Mimus dorsalis Scientific name definitions

If this mockingbird did not venture south to parts of NW Argentina it would be a Bolivian endemic, as overwhelmingly the main part of its distribution is squarely in Bolivia. It is found in dry rain shadow valleys in the mid elevations of the Andes, largely between 2500 and 3500 m. It takes arid shrubby scrub, usually areas with tall cacti, but even the edges of Andean villages and agricultural land. It is likely most closely related to the White-banded Mockingbird (Mimus triurus) as it shares many aspects of plumage such as extensive white on the outer tail, and a white wing patch. However, the white patch on the wings is restricted to the primary coverts and primary bases on this mockingbird. Also as the name implies, the warm brown wash on this mockingbird extends from the rump up to the back, so it looks more uniform than the grayish backed White-banded. This mockingbird is resident and unlikely to be seen away from its regular distribution.

21–25·5 cm; 52–65 g, average 58·7 g. Medium-sized brownish mockingbird. Has prominent whitish supercilium , dusky lores and ear-coverts; crown and upperparts chestnut-brown, brightest on rump , crown with darker streaks; upperwing-coverts tipped narrowly white (two narrow white wingbars), primary coverts white; flight-feathers and tail blackish, bases of primaries white and outer 3–4 rectrices white (conspicuous white wing and tail markings in flight); whitish below , tinged buff on chest , sides and flanks; iris brownish; bill and legs black. Differs from M. triurus in slightly larger size, heavier bill, browner back, less white in wing. Sexes similar, but female slightly smaller than male. Juvenile has dusky spotting on breast.

W & S Bolivia (S from La Paz) and NW Argentina (S to Tucumán).

Resident; report of vagrant in Chile (Arica) apparently questionable, but there is a recent (Aug 2013) documented record from Peru (Cuzco) (1 Ugarte, M., Angulo, F., Lane, D.F., Lloyd, H., O’Neill, J., Plenge, M., Schulenberg, T., Valqui, T., Walker, B. and Zepilli, R. (2014). Reporte del Comité de Registros de Aves Peruanas (CRAP) del periodo 27313. Bol. UNOP. 9(3): 45–54. Close ).

Feeds largely on ground , holding tail cocked. No information on diet or foraging behaviour.

Song is a series of repeated harsh notes and chuckles; reportedly much inferior in vocal array and melodic quality to that of M. triurus.