Plain-breasted piculet Plain-breasted piculet The plain-breasted piculet ("Picumnus castelnau") is a species of bird in the woodpecker family. It is found in the Ucayali and Amazon floodplains in eastern Peru. Its natural habitats are subtropical or tropical moist lowland forests and heavily degraded former forest. A small bird with a short tail, the plain-breasted piculet typically grows to a length of . It is mostly grey on the face and its nape and upper neck are finely barred in an olive green color. Its mantle and back are an olive, brown or grey color with slight pale barring and a light yellowish-brown,
White-barred piculet northeastern Brazil; "P. c. thamnophiloides" found in southeastern Bolivia and northeastern Argentina; "P. c. tucumanus" found in northwestern Argentina; the Pilcomayo piculet, "P. c. pilcomayensis" found in southeastern Bolivia, Paraguay and northeastern Argentina; and the nominate subspecies "P. c. cirratus" found in southeastern Brazil, southern Mato Grosso and eastern Paraguay. The taxonomy of this species is difficult; the races "pilcomayensis", "thamnophiloides" and "tucumanus" intergrade in northern Argentina and are sometimes considered a separate species, and "pilcomayensis" intergrades with "cirratus" in eastern Paraguay. The northern subspecies, "confusus" and "macconnelli" may also be a distinct species. The white-barred piculet also hybridizes widely