The  Andean Hillstar male moves around in grasslands while the female performs alone  all the nesting duties. 
    The  birds may disperse to adjacent warmer areas during the southern winter.  
This species hovers less than other hummingbirds and only performs short-distance flights.
REPRODUCTION OF THIS SPECIES:  
    The  breeding season takes place between September and February. 
    The  territory is held and defended by the female. It is established in gorges where  bushes are growing among rocks. 
    The nest  is a bulky structure, a large cup-shaped nest glued to a rock surface or under  an overhanging rock. It is usually made with moss and lichen held together with  spider webs. This well-insulated structure is often placed on the eastern face  of rocks to catch the morning sun. It may also be built in a shallow cave.   
    In very  suitable locations, several females may nest semi-colonially. 
The  female lays two eggs and incubates alone during 20 days. She feeds the chicks  alone and the young fledge about 38 days after hatching, or less in warmer  places. A second clutch is sometimes possible. 
    The  young birds are fully fledged at about fine weeks old. During this period, the  male moves out to live at higher elevation. 
PROTECTION / THREATS / STATUS:  
    The  Andean Hillstar is described as the “commonest puna bird” although it is less  common in areas where plant diversity is reduced by overgrazing and traditional  fires. However, the species is present in several protected areas.
    The size  of the population is unknown, but it is suspected to be stable. 
    The  Andean Hillstar is not globally threatened and currently evaluated as Least  Concern. 
Fr: Colibri d’Estelle – Colibri Estelle
    Ang: Andean Hillstar
    All: Estella-Andenkolibri
    Esp: Colibrí puneño - Estrella Andina
    Ita: Orostella delle Ande
    Nd: Estellabergnimf
    Sd: punabergstjärna 
Photographers:
John Anderson 
      John Anderson Photo Galleries 
Dubi Shapiro 
    Dubi Shapiro Photo Galleries 
Text by Nicole Bouglouan
Sources:
HANDBOOK OF THE BIRDS OF THE WORLD Vol 5 by Josep del Hoyo-Andrew Elliott-Jordi Sargatal - Lynx Edicions - ISBN: 8487334253
Birds of Ecuador De Robin Restall, Juan Freile – Editeur: Bloomsbury Publishing, 2019 – ISBN: 147297249X, 9781472972491 - 576 pages
Nature Guide Birds of the World De DK – Editeur: Dorling Kindersley Ltd, 2012 – ISBN: 1409375471, 9781409375470 – 352 pages
A Wildlife Guide to Chile: Continental Chile, Chilean Antarctica, Easter ... De Sharon Chester – Editeur: Princeton University Press, 2010 – ISBN: 1400831504, 9781400831500 – 400 pages
BIRDS OF PERU by Thomas S. Schulenberg, Douglas F. Stotz, Daniel F. Lane, John P. O’Neill, Theodore A. Parker III – Princeton University Press 2007– ISBN: 978-0-691-13023-1
Arthur Grosset's Birds (Arthur Grosset)
Wikipedia, the free encyclopaedia
Wikipedia, la enciclopedia libre
Andean Hillstar
      Oreotrochilus estella
Apodiformes Order – Trochilidae Family
INTRODUCTION:
    Like  other Oreotrochilus species, the Andean Hillstar lives in puna grasslands,  especially around rocky crops at high elevation in the central plateau of the  Andes. It is found from SW Peru, through W Bolivia and N Chile to NW Argentina.  Two subspecies share this range. 
    It feeds  on nectar from flowers of Chuquiragua spinosa and other plant species. It nests  in a large structure built under overhanging rocks or glued to a rock surface,  sometimes in caves. 
    Like  other hillstars, it feeds by clinging to branches instead of hovering. During  the cold nights, it enters a state of torpor to survive and conserve energy. 
    Within  the pairs, the territorial roles are reversed. The female holds and defends the  breeding territory, and she also raises the chicks alone while the male moves  to higher elevations. 
    The  Andean Hillstar is not globally threatened and the population is currently  stable. 
The name of this species pays tribute to Estelle-Marie Dessalines d’Orbigny, the elder sister of the French zoologist Alcide Dessalines d’Orbigny.
DESCRIPTION OF THE BIRD:
      Biometrics:    
    Length:  13-15 cm
    Weight:  M: 8,8 g – F: 8 g
The  Andean Hillstar is a medium-sized Trochilidae. 
    The  adult male has greyish-green to greyish-brown upperparts. Flight-feathers and  rectrices are bluish-black. 
    On the  white underparts, the broad, iridescent green gorget contrasts strongly with a  black collar and the pale underparts. There is a rufous-brown median stripe on  belly. Breast sides and flanks are buffy-white. On the undertail, the central  pair of rectrices is dark green, whereas the outer rectrices are white with  dusky edging. 
The  slightly curved bill is black. The eyes are dark brown. Legs and strong feet  are blackish. 
    Both  male and female show a small white spot on the rear eye. 

The  adult female is duller, with greyish-green upperparts and mostly greyish  underparts. The white throat shows fine, dusky specks. Bases and tips of  rectrices are white. Flight-feathers are dark brown with blue/green  iridescence.  
    She  resembles female Ecuadorian Hillstar, but she is greener above and  greyer below. 
The  juvenile is more greyish. The base of the mandible is yellow. 
    The  immature has dark glaucous gorget. 
SUBSPECIES AND RANGE:   
    The  Andean Hillstar has two subspecies.
  O.e. estella (described above and displayed) is found in  the Andes of SW Peru, W Bolivia, N Chile and NW Argentina. 
O.e. bolivianus occurs in the Andes of C Bolivia (Cochabamba). 
    In this  race, the male has chestnut, spotted black median stripe on belly. 
HABITAT:   
    The  Andean Hillstar is usually found in the sparse vegetation and grasslands of the  Puna Plateau in the Andes, often around rocky outcrops and in places where it  can feed on nectar from flowering shrubs. It is relatively common near habitations  and at the edges of woodlands with Polylepis and areas with Bromeliaceae. 
    During  the breeding season, the female establishes the breeding territories near rocks  in bushy gorges. 
    The  species is present from 2,400 to 5,000 metres of elevation, but it is commonest  between 3,500 and 4,500 metres. 
CALLS AND SONGS: SOUNDS  BY XENO-CANTO 
    The call  of the Andean Hillstar is a short, repeated “tsip”. During chasing, it gives  rapid, melodious twittering. 
BEHAVIOUR IN THE WILD:
    The  Andean Hillstar feeds on nectar from several flowering plant, but especially  Chuquiragua spinosa shrubs and low cushion cacti, occasionally Eucalyptus. Insects  are also taken while drinking nectar from plants, or gleaned from vegetation or  caught in flight. 
Unlike most Trochilidae species, the Andean Hillstar usually clings to flowers while feeding. Like other mountain hillstars, it hovers less often than other hummingbirds to save energy in the cold mountain air. The strong feet are well-adapted to this behaviour.
These birds have special adaptations to survive cold nights. As the temperature falls, their own bodies cool and enter a state of torpor every night, in order to be able to conserve energy. They return to flowers for feeding as soon as their bodies warm up when the sun rises. They also may seek shelter in caves that also protect them from nocturnal predation.
During the breeding season, the female holds and defends the territory. She builds the nest and raises the chicks alone.
