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Oreotrochilus estella

Andean Hillstar

  • Order: Apodiformes
  • Family: Trochilidae
  • Polytypic 3 Subspecies

Authors: Johnson, Andy

Identification

Summary

Andean Hillstar is a fairly large hummingbird with a medium-sized, slightly decurved, black bill. Males have pale olive gray upperparts, with mostly white underparts punctuated by a tapered median belly stripe of dark rufous. The bright emerald gorget is bordered in contrasting black. Females are generally browner above, have duller white underparts, a more mottled belly stripe, and a white throat regularly flecked with green. Both sexes have dusky flanks, and mostly white tails, with black central rectrices, and black tips and webs in the rest of the tail. Juveniles are browner, similar in appearance to females.

Similar Species

Andean Hillstar is similar only to other species of Oreotrochilus, with which it is allopatric or narrowly sympatric:

1) White-sided Hillstar (Oreotrchilus leucopleurus):
The median belly stripe of the male is broader and more rounded, and blue-black, instead of chestnut. The gorget’s black border is perhaps narrower than that of Andean. The tail is less notably forked, due to its shorter, inward-curving outer rectrices, which lack white at the tips and in the outer webs, and narrow throughout their length (the outer rectrices of Andean have relatively narrow tips but broaden at the base). Both females and juveniles of White-sided have a central, blue black bar across the upperside of the tail, where white is lacking from the rectrices’ webs, but probably are not distinguishable from Andean under field conditions. White-sided tends to be slightly smaller as well. White-sided and Andean hillstars are not known to be sympatric.

2) Ecuadorian Hillstar (Oreotrochilus chimborazo):
The general plumage characteristics are similar to Andean, but male Ecuadorian has a violaceous hood, extending into the nape, and the gorget is violaceous or is violaceous and green; Andean has a green crown, and the gorget is entirely emerald green. This species also averages slightly larger than Andean and White-sided (Zimmer 1953). Ecuadorian and Andean hillstars are allopatric.

3) Black-breasted Hillstar (Oreotrochilus melanogaster): Black-breasted Hillstar is endemic to central Peru; it locally is sympatric with Andean Hillstar (subspecies stoltzmanni) in Pasco. Male Black-breasted Hillstar is very distinctive, with a green gorget (as in Andean) but an entirely black breast and belly; there also is no white in the tail. Female Black-breasted Hillstar is very similar to female Andean, but the bases of the rectrices are dark, with white confined to the tips of the rectrices.

Vocalizations

Calls of Andean Hillstar include a high pwee-whheet pwee-whheet pwee-whheet (Jaramillo 2003) and "fine tij and zirr notes" (Fjeldså and Krabbe 1990). The song of Andean Hillstar is described as a "fine passerine-like trill" (Fjeldså and Krabbe 1990).

Additional audio recordings of vocalizations of Andean Hillstar can be heard at Macaulay Library and at xeno-canto.

Nonvocal Sounds

None described.

Detailed Description (appearance)

The following description is based on Fjeldså and Krabbe (1990) and on Jaramillo (2003); see also Geographic Variation.

Male: Adults are pale greenish brown or drab brown above with clean white underparts punctuated by a dark rufous median belly stripe (nominate estella), which tapers to a point in the middle of the breast. The black bill is of medium length (20.5 mm), and slightly decurved (Johnson 1967), and the feet are relatively large, presumably suited for clinging to rocks during torpor. The head and face are a clean, sandy gray, and the gorget bright emerald, bordered narrowly by a black collar that strongly contrasts with the white underparts. The wings are darker, and the uppertail is a steely blue, with white-tipped and white-based outer rectrices, forming a dark band across the middle of the outer tail. The undertail is predominantly white, with varied black markings.

Female: Similar in structure to male. Upperparts dull greenish brown, underparts pale gray brown. The pale gray throat is marked regularly with iridescent green flecks. Rectrices greenish black, outer 3-4 pairs of rectrices with white bases and tips.

Juvenile: Similar in appearance to female, but lacks green flecks on the throat and may show a pale yellow base to the mandible.

Bare Parts

Dark iris, black bill and feet. 

Measurements

Total length: 13-14 cm (Jaramillo 2003), 14 cm (Fjeldså and Krabbe 1990)

Linear measurements:

wing length, 66.4 mm (n = 1, sex?; Brown and Bowers 1985); 70-76 mm (n = ?; Zimmer 1951)

tail length, 45-52 mm (n = ?; Zimmer 1951)

culmen, 20.5 mm (Johnson 1967); male, mean 19.8 mm (n = 7; Carpenter 1976); female, mean 19.2 mm (n = 13; Carpenter 1976)

Mass: mean 8.4 g (n = 24, sexes combined; Carpenter 1976); males, mean 8.8 g (n = 13; Carpenter 1976); females, 8.0 g (n = 11; Carpetner 1976).

mean 8.11 g (n = 37, ± 0.39, sexes combined?; Brown and Bowers 1985)

Molts

No information available.

Geographic Variation

Three subspecies are recognized (Fjeldså and Krabbe 1990)

stolzmanni Salvin 1895; type locality Huamachuco, 10400 feet and near Cajamarca, 10000 and 12000 feet, Perú

Occurs from extreme southern Ecuador south through the Andes to central Peru in Huánuco, Lima, and Pasco.

Similar to nominate estella, but the median breast band of the male is black, and the upperparts in both sexes are bronzier (Fjeldså and Krabbe 1990).

estella (d'Orbigny and Lafresnaye 1838); type locality La Paz and Potosí, Bolivia

Occurs from south central Peru (Ayacucho, Apurímac and Cuzco) south through northwestern Bolivia to northern Chile (Tarapacá).

See Detailed Description.

bolivianus Boucard 1893; type locality Bolivia, restricted to Lagonillas, 3500 m, Cochabamba, Bolivia

Median breast stripe of male broad and chestnut, somewhat spotted with black; gorget often blue green, not bright green.

Occurs in southern Bolivia and in northwestern Argentina.

Systematics

Oreotrochilus estella sometimes is considered to be a member of a superspecies including O. chimborazo (Ecuadorian Hillstar)O. leucopleurus (White-sided Hillstar), and perhaps also O. melanogaster (Black-breasted Hillstar) (Schuchmann 1999). The number of species recognized within this complex varies widely. Zimmer (1951) included chimborazo and leucopleurus in estella, but maintained melanogaster as a separate species. Most recent authors recognize chimborazo and leucopleurus as distinct species, but treatments differ over the inclusion of stolzmanni in estella. The distribution of melanogaster, in central Peru, separates stolzmanni, which occurs from southern Ecuador to central Peru, from the southern taxa of estella (nominate estella, bolivianus); some authors recognize stolzmanni as a separate species (e.g. Schuchmann 1999).

Phylogenetic analysis of DNA sequence data, from both mitochondrial and nuclear genes, indicates that Oreotrochilus is embedded within a radiation of Andean hummingbirds (McGuire et al. 2007, 2009). Within this radiation, Oreotrochilus is basal to a clade that includes Opisthoprora, Lesbia, Ramphomicron, Chalcostigma, Oxypogon, Oreonympha, and Metallura (McGuire et al. 2007, 2009).

Recommended Citation

Johnson, Andy. 2012. Andean Hillstar (Oreotrochilus estella), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=263096