White-sided Hillstar Oreotrochilus leucopleurus Scientific name definitions

Amongst the genus Oreotrochilus, the White-sided Hillstar has the largest geographical range. It is found southern Bolivia as far south as southern Argentina, and at altitudes between at least 1200 and 4000 m, and sometimes as high as the snowline. Despite its hardy nature, at least some apparently depart Chile in the austral winter. In terms of plumage, the White-sided Hillstar is generally very similar to the Andean Hillstar (Oreotrochilus estella), with which the present species forms a superspecies, being largely bronzy-green above and white below, with a green throat in males, and a gray-spotted throat in females. Both sexes show extensive white in the otherwise dark tail.

13–15 cm (bill 2 cm), 7·9–8·4 g. Bill slightly curved, black. Resembles <em>O. estella</em> , with which there is potential geographical overlap in austral winter (1 Jaramillo, A. (2003). A Field Guide to the Birds of Chile Including the Antarctic Peninsula, the Falkland Islands and South Georgia. Christopher Helm, London, UK. Close ), but male has broad blue-black median stripe below , and tail more rounded because of shorter, narrower and inwards-curving outer rectrices, which are white only at base. Female and juvenile both extremely difficult to separate from <em>O. estella</em> and, in some cases, perhaps impossible, but have narrow outer rectrices (throughout their length) (1 Jaramillo, A. (2003). A Field Guide to the Birds of Chile Including the Antarctic Peninsula, the Falkland Islands and South Georgia. Christopher Helm, London, UK. Close ) with complete and even-width (1 Jaramillo, A. (2003). A Field Guide to the Birds of Chile Including the Antarctic Peninsula, the Falkland Islands and South Georgia. Christopher Helm, London, UK. Close ) dark green transverse bar. However, overall, the outer three tail feathers in O. leucopleurus have more white (and less green) than in O. estella, meaning that the dark band appears more reduced (with white breaking the shafts) compared to the latter species, whose tail pattern appears crisper (1 Jaramillo, A. (2003). A Field Guide to the Birds of Chile Including the Antarctic Peninsula, the Falkland Islands and South Georgia. Christopher Helm, London, UK. Close ).

S Bolivia (Tarija; winter records from Cochabamba (2 Herzog, S.K., Soria A., R. and Matthysen, E. (2003). Seasonal variation in avian community composition in a high-Andean Polylepis (Rosaceae) forest fragment. Wilson Bull. 115(4): 438–445. Close ) ) S through Andes to SC Chile (Bío-Bío) and S Argentina (WC Santa Cruz).

Puna with dwarf bushes, columnar cacti and Puya, at 1200–4000 m, sometimes even to the snow-line.

During the southern winter normally leaves its Chilean territory, but a record in Jul at 600 m in N Chile demonstrates altitudinal displacements within Chile. Recently recorded 400 km N of known range in Cochabamba (Bolivia) in austral winter/spring (Jun–Oct) (3 Herzog, S. K., R. Soria, and E. Matthysen (2003). Seasonal variation in avian community composition in a high-Andean Polylepis (Rosaceae) forest fragment. Wilson Bulletin 115(4):438–445. Close ).

Probably as O. estella; feeds on nectar from flowers of Barnadesia, Berberis and Chuquiragua bushes, larger Puya species and probably some herbs.

Poorly known. Calls include a repeated short “tsit”. Also a fast twittering during chasing or display, similar to O. estella.

Nov–Dec. Large cup-shaped nest is glued to a vertical rock-face, usually in a well-protected site. Clutch size two eggs. No further information.

Not globally threatened. CITES II. Generally common; limits of range in Argentina recently found to extend much further S than previously thought. Large tracts of core habitat are under slight pressure from man, including several protected areas of considerable extent, such as Perito Moreno and Los Glaciares National Parks (4 Darrieu, C. A., A. R. Camperi, and S. Imberti (2008). Avifauna (non Passeriformes) of Santa Cruz province, Patagonia (Argentina): annotated list of species. Revista del Museo Argentino de Ciencias Naturales 10:111–145. Close ), Laguna de Los Pozuelos, Olaroz-Cauchari, Laguna Brava, San Guillermo, Volcán Tupungato and Lanín (Argentina); also present in Cerro La Campana National Park (Chile).