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ORNITOLOGIA NEOTROPICAL 18: 449–452, 2007 © The Neotropical Ornithological Society

DIET OF THE PATAGONIAN SIERRA-FINCH (PHRYGILUS PATAGONICUS) ON NAVARINO ISLAND,

Steven M. McGehee1,2 & Jack Clinton Eitniear2

1Parque Ethnobotánico Omora, Universidad de Magallanes, Fundación Omora, Isla Navarino, Magallanes, Chile. 2Center for the Study of Tropical Birds Inc., 218 Conway Drive, San Antonio, Texas 78109, USA. E-Mail: [email protected]

Dieta del Cometocino patagónico (Phrygilus patagonicus) en la Isla de Navarino, Chile. Key words: Patagonian Sierra-finch, Phrygilus patagonicus, Chile, diet, Navarino Island.

The Patagonian Sierra-finch (Phrygilus patagoni- Omora Ethnobotanical Park (54°55´S, cus) is one of the most abundant species in the 67°39´W). The park is located at the northern Subantarctic Magellanic evergreen forest end of Navarino Island (Anderson et al. 2002), ecoregion (Anderson & Rozzi 2000). It ranges 5 km east of the town of . from sea level to 1800 M and is most often Navarino Island receives 650 mm of precipi- seen in forests (Rozzi et al. 2003, Martínez & tation annually with a mean annual tempera- González 2005) and forest borders or ture of 6°C (di Castri & Hajek 1976). The shrubby cleared areas in southern Chile and northern part of the island is characterized by (Ridgely & Tudor 1989, old growth southern beech ( betu- Vuilleumier 1991). In spite of its high abun- loides) and Lenga Beech (N. pumilio) forests dance and potentially key ecological role, little along with areas of second growth, burned is known about the diet of this species and areas and areas converted to pasture land. sierra-finches (genus Phrygilus and subfamily Observations of foraging were made from sea Emberizinae) in general. Published records of level to above the at 750 m with 8x10 Patagonian Sierra-finch diet consist of anec- binoculars. dotal observations, stomach contents (Hum- The results of our observations are sum- phrey et al. 1970) and observations of marized in Table 1. We documented utiliza- robbing (Traveset et al. 1998). We present here tion of two tree species, four flowering , Patagonian Sierra-finch dietary information at six grasses, and a single species of lichen that the southern extreme of its distribution on had not previously been recorded as food Navarino Island (55ºS), County, items. We also reaffirm the use of Chilean Chile. firebush (Embothrium conocidium) and winter’s From 25 September 2004 to 12 May 2006, bark ( winteri) as food sources. Patago- Patagonian Sierra-finches were observed in nian Sierra-finches were observed in all

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TABLE 1. Fifteen plants consumed by the Patagonian Sierra-finch (Phrygilus patagonicus) on Navarino, Island, Chile.

Plant species Parts of consumed Months , buds,floral parts Nov. Sep., Feb. Embothrium coccineum Seed, nectar Oct., Dec., Jan., Mar., Apr. Perezia magellanica Seed Mar. Carex curta Seed Mar. Rumex sp.* Seed Sep. Taraxacum officinale* Seed Nov., Dec. Poa pratensis* Seed Jan. Holcus lanatus* Seed Jan. ilicifolia Nectar, floral parts Oct. Berberis boxifolia , nectar, floral parts Oct., Nov., Feb. Ribes magellanicum Fruit Feb. Chiliotrichum diffusum Floral parts Jan Drimys winteri Fruit, floral parts Jan., Mar., Apr., May magellanica Fruit Apr. Usnea spp. All Mar., Apr.

*Non-native species. trophic levels of the forest and clearings. Sierra-finches are “terrestrial when foraging”. While feeding observations were of birds on In consideration of these contrasting state- the ground or in the lower 4 m of trees and ments no singular trophic level within the for- , Patagonian Sierra-finches were often est appears to be preferred. Rather the species seen high up in beech trees and was noted is likely inhabiting the level within the forest to be a member of foraging flocks of the where food resources are most abundant. Thorn-tailed Rayadito (Aphrastura spinicauda) Patagonian Sierra-finch diet is described and the White-throated Treerunner (Pygarrhi- as being composed of , buds, , chas albogularis) and may have been consuming fruit, insects and other invertebrates (Egli & insects but was too high in the canopy to Aguirre 2000). Specific documentation observe. The only non-vegetative item noted includes feeding on the nectar of Chilean fire- in the diet was grit recovered in the stomachs bush (Smith-Ramirez & Armesto 2003), Chil- of two individuals that died in the nets. ean needletree (Rhaphithamnus cyanocarpus) The species preferred habitat appears (Barros 1945), Austral bellflower (Philesia unclear. Observations of sierra-finches rob- magellanica) (Rozzi et al. 2003) and hardy bing nectar of hardy fuschsia ( magella- fuschsia (Blumberg undated, Traveset et al. nica) were recorded as being principally in 1998). Patagonian Sierra-finch has also been open habitat followed by forest then forest observed to consume the flowers and fruit of edge (Traveset et al. 1998). Couve & Vidal winter’s bark (Chebez & Bertonatti 1994) and (2003) state that it is “generally seen in the phloem-sap of southern beech (Schlatter & canopy or middle story where it feeds” while Vergara 2005). Seeds have been noted in Jaramillo (2003) remarks that Patagonian stomach samples (Humphrey et al. 1970,

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Markham 1970, Rozzi et al. 1996) as well as earlier drafts. Special thanks to C. Anderson, insects, pebbles, and vegetable matter (Schlat- X. Arango, S. Ippi, F. Massardo, R. Rozzi and ter et al. 1995). Finally, Crawshay (1907) M. Sherriffs for their assistance in logistics. reported that, around human settlements, it Support for this project came from the subsisted largely on refuse and he observed Omora Foundation and the Millennium some individuals pecking at a raw sheep’s Project, IEB, University of Chile. head and beef bone. Our observations add to the known list of REFERENCES items foraged on. Two plants noted as food items in other papers, Chilean needletree and Anderson, C., & R. Rozzi. 2000. Bird assemblages hardy fuschsia, do not grow on Navarino in the southernmost forests in the world: Meth- Island (Moore 1983), so could not be utilized odological variations for determining species by sierra-finches. The four exotic species of composition. An. Inst. Patagon. 28: 89–100. grasses they consumed were introduced in the Anderson, C., R. Rozzi, C. Elphick, & S. McGehee. last 150 years as forage for livestock in Tierra 2002. El programa Omora de anillamiento de del Fuego. We found no evidence that Patago- aves en los bosques subantárticos: estandariza- ción del tamaño de anillos apropiados para las nian Sierra-finches play a significant role as aves de la region de Magallanes. Bol.Chil. Orni- seed dispersers. The observed method of tol. 9: 2–11. feeding consists of thoroughly grinding and Barros, V. 1945 Aves polinizadores y flores orni- crushing all food items before swallowing. On tofilas de Maullin. Rev. Univ. 30:73–78. large of species such as winter’s bark Blumberg, C. A. Sin fecha. Contemplando aves y and Magellan barberry (Berberis boxifolia), they mamíferos de Aisén. Univ. de Los Lagos, took off small chunks of fruit, rarely getting Osorno, Chile. any seeds in the center. A study of over 100 Couve, E., & C. Vidal. 2003. Birds of , Patagonian Sierra-finch feces from birds cap- and Antarctic Peninsula, the tured in mist nets in Omora Park revealed no Falkland Islands and South Georgia. Editorial whole seeds had passed through after diges- Fantástico Sur, , Chile. Chebez, J. C., & C. C. Bertonatti. 1994. La avifauna tion (S. Ippi pers. com.). This species has pre- de la isla de Los Estados, isles de Año Nuevo y viously been noted as a destroyer of flowers mar circundante. Monografia Especial No. 31, with nectar (Traveset et al. 1998, Smith- Literature of Latin America (L.O.L.A.), Buenos Ramirez & Armesto 2003), a behavior we also Aires, Argentina. observed. The Patagonian Sierra-finch Crawshay, R. 1907. The birds of Tierra del Fuego. appears to act as a seed predator and a nectar Bernard Quaritch, London, UK. robber. Its evolutionary relationship with the Di Castri, F., & E. R. Hajek. 1976. Bioclimatología native plants inside its range and a more thor- de Chile. Univ. Católica de Chile, Santiago, ough study of this species diet remains to be Chile. conducted. Our observations add to the Egli G., & J. Aguirre C. 2000. Aves de Santiago. known list of items foraged on. UNORCH, Santiago, Chile. Fjeldsa, J., & N. Krabbe. 1990. The birds of the High Andes. Zoological Museum, Univ. of ACKNOWLEGMENTS Copenhagen, Copenhagen, Denmark. Humphrey, P. S., D. Bridge, P. W. Reynolds, & R. T. We thank R. Charlin, D. Christie, O. Dollenz, Peterson. 1970. Birds of Isla Grande (Tierra del A. Gutiérrez and F. Massardo for identifying Fuego). Preliminary Smithsonian Manual, the plant species. Thanks to C. Anderson, R. Smithsonian Institution, Washington, D.C. Rozzi and J. C. Torres-Mura for comments on Jaramillo, A. 2003. Birds of Chile. Princeton Univ.

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Press, Princeton, New Jersey. Guía multi-étnica de aves de los bosques temp- Johnson, A. W. 1967. Birds of Chile and adjacent lados de Sudamérica austral. Editorial Fantás- regions of Argentina, Bolivia and Peru. Volume tico Sur, Punta Arenas, Chile. II. Platt Establecimientos Gráficos, Buenos Schlatter, R., & P. Vergara. 2005. Magellanic Wood- Aires, Argentina. pecker (Campephilus magellanicus) sap feeding Markham, B. J. 1970. Reconocimiento faunístoco and its role in the Tierra del Fuego forest bird del área de los fiordos Toro y Condor, Isla assemblage. J. Ornithol. 146: 188–190. Riesco, Magallanes. An. Inst. Patagon. 1: 41– Schlatter, R. P., C. Venegas, C. Bravo, & J. C. 57. Torres-Mura. 1995. Proyecto rió Cóndor Tierra Martínez P., D., & G. González C. 2004. Las aves del Fuego. Aves. Informe científico, Univer- de Chile. Ediciones del Naturalista, Santiago, sidad Austral de Chile, Valdivia, Chile. Chile. Smith-Ramirez, C., & J. J. Armesto. 2003. Foraging Moore , D. M. 1983. Flora of Tierra del Fuego. behavior of bird pollinators on Embothrium Missouri Botanical Gardens, St. Louis, Mis- coccineum (Proteaceae) trees in forest fragments souri. and pastures in southern Chile. Anim. Ecol. 28: Ridgely, R., & G. Tudor. 1994. The birds of South 53–60. America. Volume 1. The Oscine Passerines. Traveset, M. F., M. F. Willson, & C. Sabag. 1998. Univ. of Texas Press, Austin, Texas. Effect of nectar-robbing birds on fruit set of Rozzi, R., J. J. Armesto, A. Correa, J. C. Torres- in Tierra Del Fuego: a dis- Mura, & M. Sallaberry. 1996. Avifauna de rupted mutualism. Funct. Ecol. 12: 459–464. bosques primarios templados en islas deshabi- Vuilleumier, F. 1991. A quantitative survey of spe- tadas del Archipielago de Chiloé, Chile. Rev. ciation phenomena in Patagonian birds. Orni- Chil. Hist. Nat. 69: 125–139. tol. Neotrop. 2: 5–28. Rozzi, R., F. Massardo, C. B. Anderson, S. McGe- hee, G. Clark, E. Ramilo, U. Calderón, C. Calderón, L. Aillapan, & C. Zárraga. 2003. Accepted 6 January 2007.

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