Male Picumnus aurifrons aurifrons
|Range||Bolivia, Brazil, Colombia, and Peru.|
Its natural habitats are subtropical or tropical moist lowland forests and sometimes in heavily degraded former forest. The bar-breasted piculet is generally found in humid forests, including terra firme and várzea, and are generally seen within such areas in the edges, second growth, and clearings.
This species is of note as the smallest extant species in the highly diverse woodpecker family. A typical adult will measure only 7.5 cm (3.0 in) in length and will weigh 8 to 10 g (0.28 to 0.35 oz). Among standard measurements, the wing chord is 4.4 to 5.3 cm (1.7 to 2.1 in), the tail is 2.3 to 2.6 cm (0.91 to 1.02 in), the bill is 0.9 to 1.2 cm (0.35 to 0.47 in) and the tarsus is 1.1 to 1.2 cm (0.43 to 0.47 in). These yellowish green piculets have horizontal barring on the chest and vertical streaking on the belly. Several different subspecies exist throughout their large range. Unfortunately, very little is known about their life history and basic ecology.