Glacier Finch Idiopsar speculifer Scientific name definitions

The Glacier Finch is a peculiar passerine of the high Andes in Peru, Bolivia, Argentina, and Chile. Although its primary habitat is puna grasslands, it has a high affinity for water and can be found near bogs dominated by cushion plants. This strongly terrestrial species is mostly gray with a white throat, white arc under the eyes, and dark gray wings with white outer primaries. The genus of this species was recently switched from Diuca to Idiospar where it is now placed with the Boulder Finch Idiopsar brachyurus (see Related Species).

Recent evidence suggests that the Glacier Finch is one of two birds in the world (along with the White-fronted Ground-Tyrant Muscisaxicola albifrons) that routinely construct its nest directly on ice (1 Hardy, D. R., and S. P. Hardy (2008). White-winged Diuca Finch (Diuca speculifera) nesting on Quelccaya Ice Cap, Peru ́. Wilson Journal of Ornithology 120 (3):613-617. Close , 2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ) and may be at least somewhat dependent on Andean glaciers for reproduction. Along with this unique behavior, the Glacier Finch has also been found roosting in glacier caves and may be one of the highest nesting passerines in the Western Hemisphere at 5300 m (1 Hardy, D. R., and S. P. Hardy (2008). White-winged Diuca Finch (Diuca speculifera) nesting on Quelccaya Ice Cap, Peru ́. Wilson Journal of Ornithology 120 (3):613-617. Close ).

The Glacier Finch is a large terrestrial finch. Apart from an obscure white section of the otherwise black outer primaries, this gray species has a white belly, a white throat and a white arc below the eye. From a distance the white is often not visible, but the short bill and front heavy body lend to a distinctive shape.

The White-throated Sierra Finch (Phrygilus erythronotus) is another white and gray passerine, which shares similar habitat in the southern parts of the Glacier Finch's range. However, it lacks the white in the primaries and has a smaller white crescent below the eye.

The description of the adults is based on Fjeldså and Krabbe (3 Fjeldså, J., and N. Krabbe (1990) Birds of the high Andes. Zoological Museum, University of Copenhagen, Copenhagen, Denmark. Close ).

Adult: Sexes similar. Slate gray overall with a white throat and belly. Bright red eyes with dark lores and a white crescent under the eye. Primaries blackish with white bases that appear as a white wing patch on perched birds.

Juvenile: Very similar to the adults. Gape yellow (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

Undescribed.

Iris: red

Bill: black

Tarsi and toes: gray

Gape: yellow

Bill length (see Geographic variation) from Carriker (4 Carriker, M.A. (1935). Descriptions of new birds from Peru and Ecuador, with critical notes on other little-known species. Proceedings of the Academy of Natural Sciences of Philadelphia 87: 343–359. Close )

subspecies magnirostris: ca 16-16.5 mm

nominate speculifer: mean 14.5 mm (n = 5)

Editor's Note: This article requires further editing work to merge existing content into the appropriate Subspecies sections. Please bear with us while this update takes place.

Two subspecies recognized (4 Carriker, M.A. (1935). Descriptions of new birds from Peru and Ecuador, with critical notes on other little-known species. Proceedings of the Academy of Natural Sciences of Philadelphia 87: 343–359. Close ):

subspecies magnirostris, described as Diuca speculifera magnirostris Carriker 1935: 359 (4 Carriker, M.A. (1935). Descriptions of new birds from Peru and Ecuador, with critical notes on other little-known species. Proceedings of the Academy of Natural Sciences of Philadelphia 87: 343–359. Close ). Type locality Yanac, Ancash, Peru, 15,000 feet [4572 m]

Occurs in Andes of central Peru (Ancash, Junín, and Huancavelica).

Similar to nominate speculifer but the bill is ca 2 mm longer, and ca 1 mm higher at the base, which gives a more slender and tapered appearance (see Measurements).

nominate speculifer, descrbed as Emberiza speculifera d’Orbigny and Lafresnaye 1837: 78.

Occurs in the Andes of southern Peru (north to Arequipa, Cuzco and Puno), northern Chile (Arica–Parinacota and Tarapacá), and western Bolivia (La Paz, Cochabamba and northwestern Oruro).

Formerly placed in the genus Diuca, with the Diuca Finch (Diuca diuca), the Glacier Finch was moved to Idiospsar in light of genetic and morphological evidence (5 Burns, K. J., P. Unitt, and N. A. Mason (2016). A genus-level classification of the family Thraupidae (Class Aves: Order Passeriformes). Zootaxa 4088:329–354. Close ), suggesting Boulder Finch (Idiospar brachyurus) and Glacier Finch should be considered congeneric and are most closely related to White-throated Sierra Finch (Idiopsar erythronotus, formerly Phrygilus erythronotus) and Red-backed Sierra Finch (Idiopsar dorsalis, formerly Phrygilus dorsalis).

Diuca previously had been previously classified as a finch, e.g., a member of Fringillidae (6 Hellmayr, C. E. (1938). Catalogue of the Birds of the Americas and the Adjacent Islands in Field Museum of Natural History. Zoological Series. Vol 13. Part 11. Field Museum of Natural History, Chicago. Close ) and later as a New World Sparrow, e.g., a member of Emberizidae (7 Paynter, R. A. (1970). Subfamily Emberizinae, buntings and American sparrows. In Check-list of Birds of the World. A Continuation of the Work of James L. Peters. Volume 13 (R. A. Paynter, and R. W. Storer, Editors). Museum of Comparative Zoology, Cambridge, MA, USA. pp. 3–214. Close ). More recent work has placed Idiospar and Phrygilus with the tanagers in Thraupidae (5 Burns, K. J., P. Unitt, and N. A. Mason (2016). A genus-level classification of the family Thraupidae (Class Aves: Order Passeriformes). Zootaxa 4088:329–354. Close ).

No information.

Endemic to South America

Found in primarily in Peru, the Glacier Finch also occurs in Bolivia and northeastern Chile. This is a high-Andean species found from 3950 m (8 Schulenberg, T. S., D. F. Stotz, D. F. Lane, J. P. O’Neill, and T. A. Parker (2007). Birds of Peru. Princeton University Press, Princeton, NJ, USA. Close ) to above 5500 m (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ). It is probable that the range of this species is at least partially tied to the distribution of glaciers, which are the only known nest sites (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

Little historical abundance data is known, though there is some evidence that this species has locally declined following the disappearance of a glacier. The Glacier Finch once was locally abundant around the Chacaltaya Glacier in Western Bolivia (9 Niethammer G. (1953). Zur Vogelwelt Boliviens [The birds of Bolivia]. Bonner zoologische Beiträge 4:195–303. Close ,10 Niethammer G. (1956). Zur Vogelwelt Boliviens (Teil II: Passeres) [The birds of Bolivia (Part II: Passerines)]. Bonner zoologische Beiträge. 7:84–150. Close ). The glacier had disappeared by 2010 (11 Rabatel, A., B. Francou, A. Soruco, J. Gomez, B. Cáceres, J. L. Ceballos, R. Basantes, M. Vuille, J.-E. Sicart, C. Huggel, M. Scheel, Y. Lejeune, Y. Arnaud, M. Collet, T. Condom, G. Consoli, V. Favier, V. Jomelli, R. Galarraga, P. Ginot, L. Maisincho, J. Mendoza, M. Ménégoz, E. Ramirez, P. Ribstein, W. Suarez, M. Villacis, and P. Wagnon (2013) Current state of glaciers in the tropical Andes: a multi-century perspective on glacier evolution and climate change. Cryosphere 7: 81–102. Close ), and there are no recent eBird reports of Glacier Finch from the immediate area. Obviously more complete surveys are needed to assess if Glacier Finches have persisted in the absence of the glacier.

Glacier Finch generally is restricted to high-elevation puna, with a particular affinity for bofedales (12 Gibbons, R. E., Z. Jia, and M. I. Villalba (2016). Habitat use and seasonality of birds in the Peruvian puna with an emphasis on peatlands (bofedales). Boletín UNOP 11. Close ). At a broader landscape scale, this species seems to have a strong positive association with glaciers, perhaps due to nesting requirements/preferences (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

This species is usually seen in pairs, though in good habitat, small groups are often observed. When feeding young, pairs arrive at the nest simultaneously (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ) suggesting they are foraging together. Adults have also been observed foraging on the glacier, likely for insects such as the crane flies (Tipulomorpha sp.) that have been repeatedly observed on the ice in small numbers (see iNaturalist observations here and here).

The most common vocalization is a harsh chirp that may act as a contact call. The vocal repertoire of this species, including any possible song, is poorly documented and deserves more study.

None known.

Living in a treeless habitat, Glacier Finch is restricted to feeding on the ground. Usually in pairs this species moves slowly over the ground looking for food, flying at the approach of danger, even distant.

At dusk, this species gathers along glacier margins in preparation for roosting within crevasses and ice caves. Before entering glacier roost, pairs arrive at the margin and perch near or on the ice, only entering the "caves" when it is very dark. This behavior seems to happen year round, including during the breeding season and has been observed on several different glaciers (9 Niethammer G. (1953). Zur Vogelwelt Boliviens [The birds of Bolivia]. Bonner zoologische Beiträge 4:195–303. Close ). Roosts are thought to offer protection from harsh weather including low temperatures, high winds, and frequent snowfall (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

Little is known. When foraging and roosting, small groups appear to exist without much conflict. Multiple nests rarely, if ever, have been found in close proximity, despite a limited number of suitable nesting areas (S. P. Hardy, personal observations).

Little is known, though this species appears to be monogamous with a tight pair bond (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

Glacier Finch can be loosely associated with other terrestrial passerines, especially in and around bofedales. Nocturnal roosts in glacier caves often host dozens of Glacier Finches, and at least occasionally Plumbeous Sierra Finch (Geospizopsis unicolor) (9 Niethammer G. (1953). Zur Vogelwelt Boliviens [The birds of Bolivia]. Bonner zoologische Beiträge 4:195–303. Close , 2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

Predation at roost sites, likely by Andean Foxes (Lycalopex culpaeus), has been documented in Southern Peru. Aplomado Falcon Falco femoralis and Mountain Caracara Phalcoboenus megalopterus are other likely predators of nests and/or adults (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

The only well-documented nests of Glacier Finch come from a small area in Cordillera Vilcanota of southern Peru, where this species appears to nest exclusively on glaciers (1 Hardy, D. R., and S. P. Hardy (2008). White-winged Diuca Finch (Diuca speculifera) nesting on Quelccaya Ice Cap, Peru ́. Wilson Journal of Ornithology 120 (3):613-617. Close , 2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ). Active nests have been found in April and May, in cracks on near vertical ice faces or deep within vertical crevasses, with clutches of 2 or 3 (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ). Nests are a massive (ca 160 g dry mass) collection of grasses and twigs (1 Hardy, D. R., and S. P. Hardy (2008). White-winged Diuca Finch (Diuca speculifera) nesting on Quelccaya Ice Cap, Peru ́. Wilson Journal of Ornithology 120 (3):613-617. Close ).

Perhaps as a result of this unique breeding location in this harsh environment, several aspects of Glacier Finch biology differ from what would be expected for a passerine, at least from a Northern Hemisphere perspective.

Feeding of chicks seems to be evenly shared between the two parents, with both adults arriving at the nest simultaneously and regurgitating food to the chicks before departing with fecal sacs. Because of the distance to suitable habitat, most foraging flights are likely upwards of 500 m and could be substantially longer, as the time between feeding bouts for the one nest studied averaged just over one hour (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

Nesting in the glacier is thought to provide protection from predators, as well as weather that can be incredibly harsh. At over 5,000 m above sea level, this species is exposed to harsh winds, snow, and intense solar radiation. At the Quelccaya Ice Cap, during the breeding season, the average daily air temperature is at or just below 0°C with daily temperature swings in the realm of 8°C though the within the ice caverns average temperatures are likely several degrees warmer with smaller fluctuations (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ).

A single, active nest was filmed for 10 days in 2016 - a short clip of which can be seen here.

Currently nothing is known about the nest building, egg laying, or incubation period of this species.

Not much is known, but where present, it can be one of the most abundant passerines. If Glacier Finch is as closely associated with glaciers as it appears to be in the Cordillera Vilcanota, then the long-term viability of this species is likely to be threatened by climate change.

The IUCN Red List status of Glacier Finch is of Least Concern, although there is only very limited population data.

The Glacier Finch is found primary at high elevations in areas with limited human development. However, it likely is going to be affected by climate change, as it is closely associated with, if not dependent on, glaciers for nesting and roosting. The most immediate effect of climate change will likely be effects on snow melt and precipitation which already has started to disrupt local hydrology and wetland communities that support much of the regional biodiversity.

The biggest question about Glacier Finch is whether or not it nests anywhere other than on glaciers. To date, no nests off of glaciers have been sufficiently documented and second-hand reports exist for glacier-based nests on several glaciers in the Cordillera Vilcanota and at least one site in northern Peru (2 Hardy, S. P., D. R. Hardy, and K. Castañeda Gil (2018). Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Wilson Journal of Ornithology 130: 940-957. Close ). Finding nests away from glaciers could be difficult given the remote areas where this species lives, but a good first step would be to establish locations where this species is repeatedly found during the breeding season (April-May) that are more than a day's flight from a glacier. It would also be interesting to know if this species persists in areas where it was once found but glaciers have subsequently disappeared.

More involved research on the breeding biology of this species could better quantify the advantages of glacier nesting, which would add important information to research on avian adaption to harsh environments.