The white-barred piculet was first described in 1825 by the Dutch zoologist Coenraad Jacob Temminck. It was given the name Picumnus cirratus, the specific name meaning "curly headed", cirrus being Latin for a ringlet or curl. Molecular studies show that it is the sister species to P. temminckii and also closely related to P. dorbignyanus, and at different times these species have been treated as synonymous. Six subspecies are recognised; P. c. confusus found in southwestern Guyana, northern Brazil and French Guiana; the Marajo piculet, P. c. macconnelli found in the eastern Amazon region of 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 subspeciesP. c. cirratus found in southeastern Brazil, southern Mato Grosso and eastern Paraguay. The taxonomy of this species is difficult; the races pilcomayensis, thamnophiloides and tucumanusintergrade 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 with several other species of piculet where their ranges overlap; these include the varzea along the Amazon River, the ochre-collared in southeastern Brazil, the ocellated in Bolivia, and the white-wedged piculet, also in Bolivia.
Description
The white-barred piculet is between long. The sexes differ in that the male has red streaks or a solid red patch on the fore-crown, while the female lacks this. The rest of the crown is black, speckled with white. The upper parts of the body are tan or olive-brown, faintly barred with white, and the main flight feathers are chocolate brown. The ear coverts and cheeks are olive brown and there is a white streak above or behind the eye. The lower cheeks, chin and throat are white, faintly barred with black. The underparts are white or cream, boldly barred with black, the broadest stripes being on the belly and flanks. The tail is chocolate brown apart from the central pair of feathers which are white, and the two outer pairs which have the inner webs white near the tip. The iris is brown, the orbital ring bluish-grey, the beak black and the legs grey.
There are two different sub-populations of this bird on either side of the equator in South America. The northerly population is in Guyana, northwestern French Guiana and northern Brazil. The southern population is in southeastern Brazil, eastern Bolivia, eastern Paraguay and northern Argentina. The white-barred piculet occupies various habitats including wet and dry woodland, forest verges, thickets, gallery forests, wooded savannah, scrub, bamboo clumps, vines, creepers and overgrown parks and gardens at elevations of up to about. It is a resident, sedentary species.
Ecology
The white-barred piculet usually forages singly, but may join small mixed species flocks. It feeds on ants, their larvae and eggs, beetle larvae and other small invertebrates. It actively drills holes in wood and may also feed on sap that oozes from puncture marks. It sometimes follows swarming ants. Northern races breed between July and December, while southern races do so between September and March. The nest is a hole in a tree a few metres off the ground.
Status
This bird has a very large range and is described as being common. The population is believed to be in slow decline, because of ongoing destruction of the rainforest, but this is not happening at such a rate as to make the species vulnerable, and the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".
