Black-throated Thistletail
Asthenes harterti
Small, round, long-tailed canastero of dense understory in upper humid montane forest along the east slope of the Andes in central and NW Bolivia. Fairly common throughout range, and very inquisitive. Black throat, plump figure,and long thin raggedy tail distinctive in range. Song a fast, accelerating series of high squeaks.
Identification
The black-throated thistletail is 17 to 18 cm (6.7 to 7.1 in) long and weighs 12 to 14 g (0.42 to 0.49 oz). The sexes have the same plumage. Adults of the nominate subspecies have a rufous-brown face with a light brown supercilium. Their crown, back, rump, wings, and tail are dark rufescent brown. Their tail is long and deeply forked with few barbs at the feather ends. Their chin is grayish white and their throat black with whitish streaks. Their underparts are mostly brownish gray with browner flanks and undertail coverts. Their iris is light brown to brown, their maxilla blackish to dark gray, their mandible gray to pinkish gray with a dark tip, and their legs and feet blue-gray to gray. Subspecies A. h. bejaranoi differs from the nominate by having some ochraceous on the face and neck, and paler underparts with ochraceous sides and flanks.
Taxonomy
The black-throated thistletail and eight other species were previously placed in genus Schizoeaca but genetic data showed that the genus is embedded within Asthenes. Some authors considered all of those taxa to be conspecific but the genetic data confirm they are separate species.<p>According to the International Ornithological Committee, the black-throated thistletail has two subspecies, the nominate A. h. harterti (Berlepsch, 1901) and A. h. bejaranoi (Remsen, 1981). The Clements taxonomy treats it as monotypic. This article follows the two-subspecies model.
- Scientific name
- Asthenes harterti
- Authority
- (Berlepsch, 1901)
- Order
- Passeriformes
- Family
- Furnariidae
- Genus
- Asthenes
Range and habitat
The black-throated thistletail is found only in the Andes of western Bolivia, in the departments of La Paz, Cochabamba, and Santa Cruz. The nominate subspecies is the more northerly of the two. The species inhabits páramo grasslands, elfin forest, the ecotone at tree line, and the edge of cloudforest. In elevation it ranges between 2,900 and 3,400 m (9,500 and 11,200 ft).
- Migration
- Resident species
Behavior
The black-throated thistletail is a year-round resident throughout its range.<p>The black-throated thistletail feeds mostly on arthropods, and seeds are a small part of its diet. It forages singly or in pairs, usually in the understory though sometimes higher. It takes its prey by gleaning mostly from foliage and small branches and also moss, grass, and rocks.<p>The black-throated thistletail's breeding season has not been defined but includes at least January. It is thought to be monogamous. The one known nest was an oval mass with a side entrance, constructed of moss and a few twigs and placed on a clump of grass. The clutch size is thought to be two eggs. Both sexes provision nestlings but further details of the species' breeding biology are not known.<p>The black-throated thistletail's song is "a series of emphatic squeaky notes, accelerating and then slowing, descending slightly at end". Its alarm call is a "rodent-like 'pseea' ".
Conservation
- Population trend
- declining
Photos
Distribution
Bird Calls
Other Birds
Satyr Tragopan
Tragopan satyra
A large pheasant-like bird. Male has a black face with dark blue cheeks and chin, and a grayish-brown back and uppertail. It has white speckling all over, but the male Satyr Tragopan is the only tragopan to have white dots on the red breast. Female is similar in shape, but all brown with thin white streaks on the back and reddish-brown wings. Found in dense forests, where it forages on the forest floor. The call is a nasal, wailing “gwaaahh.”
Eastern Phoebe
Sayornis phoebe
A drab, medium-sized flycatcher. Brownish above and pale below, often with a light yellowish wash on the belly. Watch for constant tail-wagging, and also note duller wingbars than Empidonax flycatchers. Common and familiar throughout eastern North America, wintering as far south as southern Mexico. Usually seen singly or in pairs in relatively open habitats such as woodland edge, brushy fields, or edges of ponds. Often nests under eaves of buildings and other human-made structures. An early migrant, returning north to breed much earlier than other flycatchers. Listen for its harsh “FEE-bee” song in the spring, but don’t get confused by Black-capped Chickadee’s higher-pitched, sweet whistled song of a similar pattern!
Common Black Hawk
Buteogallus anthracinus
An aptly-named entirely black hawk with broad wings and short tail with a distinct white band. Flight feathers are slightly paler and it has long yellow legs and yellow on the base of the bill. Immature birds are streaky brown with dark moustache and pale eyebrow. Typically found in woodlands near water where it hunts; shows an affinity for cottonwood trees at the northern end of its range.
Start Your Bird Watching Journey
Identify a bird outdoors and keep the field guide close for your next observation.