| Sharp-billed treehunter | |
|---|---|
 | |
| Subspeciescamargoi | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Passeriformes |
| Family: | Furnariidae |
| Genus: | Heliobletus Reichenbach, 1853 |
| Species: | H. contaminatus |
| Binomial name | |
| Heliobletus contaminatus Berlepsch, 1885 | |
 | |
Thesharp-billed treehunter (Heliobletus contaminatus), sometimes called thesharp-billed xenops, is a species ofbird in the Furnariinae subfamily of the ovenbirdfamilyFurnariidae.[2] It is found in Argentina, Brazil, Paraguay, and Uruguay.[3]
The sharp-billed treehunter is assigned two subspecies, thenominateH. c. contaminatus (Berlepsch, 1885) and (as of 2023)H. c. camargoi (Cardoso da Silva & Stotz, 1992).[2][4] However, there is some confusion about thesubspecific epithets of the subspecies, and one or both might be changed.[5] In recognition of that possibility,BirdLife International'sHandbook of the Birds of the World givesH. c. camargoi thetrinomial "Heliobletus contaminatus [new name]".[6]
One author included genusHeliobletus withinXenops, as the sharp-billed treehunter's plumage is very similar to those of someXenops species. Genetic data refute this treatment and find that it belongs inHeliobletus and issister to genusPhilydor.[7]
The sharp-billed treehunter is the only member of genusHeliobletus.[2] However, one author states that "[a]n undescribed ''Heliobletus sp. occurs in SEBahia [Brazil]".[8] Recordings of this undescribed taxon have been made, and it has been found in the Serra do Lontras.[9]
The sharp-billed treehunter is 12 to 13 cm (4.7 to 5.1 in) long and weighs 13 to 15 g (0.46 to 0.53 oz). It has a short, pointed, and slightly downturned bill, and male and female plumages are alike. Adults of the nominate subspecies have a wide golden-buffsupercilium, a blackish brown band behind the eye, dark brownish and ochraceouslores, and dull buff earcoverts. Their crown is blackish brown with wide golden-olive streaks. They have a buff partial collar. Their back, rump, and uppertail coverts are dull olive-brown with rufous tips on the coverts. Their tail is dark rufous and the very end of the feathers have nobarbs. Their wings are olive-brown with darkerprimary coverts. Their throat is pale yellowish buff, their breast a paler yellowish buff with dull olive-brown streaks, their belly plain dull olive-brown, and their undertail coverts dull brownish with very wide rufous streaks. Their iris is dark brown, theirmaxilla brown to black, theirmandible pinkish gray, and their legs and feet greenish gray to dull yellow-green. Juveniles are much like adults but with a more ochraceous supercilium and streaks; the streaks are less distinct. SubspeciesH. c. camargoi has wide pale golden-buff streaks on its back, and more and wider streaks on the breast and belly.[5][8]
The nominate subspecies of the sharp-billed treehunter is found in southeastern Brazil fromMinas Gerais andEspírito Santo south toSão Paulo andRio de Janeiro states.H. c. camargoi is found fromSão Paulo south throughRio Grande do Sul and eastern Paraguay into northeastern Argentina'sMisiones Province and extreme northeastern Uruguay. The species inhabits humid lowland and montaneevergreen forest. In elevation it ranges from sea level to 1,830 m (6,000 ft).[5] The nominate subspecies tends to be more numerous at the higher elevations.[8]
The sharp-billed treehunter is a year-round resident throughout its range.[5]
The sharp-billed treehunter feeds onarthropods. It forages singly and in pairs, usually as members of amixed-species feeding flock. It feeds primarily from the forest's mid-storey to its canopy, though it will feed in the understory. It climbs and hangs acrobatically, gleaning, pulling, and pecking for its prey on branches, foliage, andepiphytes.[5][8]
Nothing is known about the sharp-billed treehunter's breeding biology.[5]
| Songs and calls |
The sharp-billed treehunter's song is "a short, harsh, metallic slow trill on one pitch, sometimes interspersed with squeaky notes or tinkling overtones". Its call is a soft "tick".[5]
TheIUCN has assessed the sharp-billed treehunter as being of Least Concern. It has a large range but its population size is not known and is believed to be decreasing. No immediate threats have been identified.[1] It is considered uncommon to locally fairly common in most of its range but rare in Paraguay. It occurs in several protected areas. However, "[e]xtensive deforestation within its relatively small range has dramatically reduced [the] area of available habitat".[5]
