Ashy-headed Goose Chloephaga poliocephala Scientific name definitions

The Ashy-headed Goose is one of a number of attractive members of the genus Chloephaga that inhabit southern South America.  This species tends to be found closer to forested areas than the Upland Goose or the strictly coastal Kelp Goose.  In flight these geese have blackish wings with a bold white leading and trailing patch that makes the species instantly recognizable as Chloephaga sheldgeese.  Males and females are similar, showing a white lower belly with dark flank barring, chestnut chest and nape, and gray upper neck and head.

50–60 cm; male 1620–2267 g, female 1470–1490 g (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Unmistakable, as grey head  , ruddy breast  , finely barred  flanks  and white belly separate this species from C. rubidiceps and C. picta (wing pattern is similar to latter). Sexes alike, female slightly smaller  with finely barred breast; bill black, legs and feet orange with dark markings, eyes dark brown with small white eyering. Juvenile has much duller rufous areas; mantle and breast more strongly barred; speculum tending towards dark brown rather than metallic green; adult plumage is attained in second year of life (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

S Chile and S Argentina, from 37° S to Tierra del Fuego; has bred in Falkland Is. In winter moves N to C Chile and Buenos Aires, Argentina.

Favours damp, southern beech (Nothofagus) forest clearings on high ground and islands, around lakes, marshes and by sea coasts (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); more associated with the Andes and southern beech forests than C. picta (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Winters on more open habitat, frequenting natural meadows and rough pastures.

Partially migratory, moving N to winter in pampas region to Buenos Aires province, Argentina, where mingles with C. rubidiceps and C. picta, and present species comprises 6–12% of geese flocks, whose densities reach 4·1–4·5 birds/km (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Has occurred E to Falkland Is, probably on an annual basis (typically between Sept and Mar) (2 Woods, R. W., and A. Woods (1997) Atlas of Breeding Birds of the Falkland Islands. Anthony Nelson, Oswestry, UK. Close ), and has occasionally bred there (perhaps even resident at one locality in West Falkland) (2 Woods, R. W., and A. Woods (1997) Atlas of Breeding Birds of the Falkland Islands. Anthony Nelson, Oswestry, UK. Close ).

Presumably mainly vegetarian; leaves, stems and seed heads of grasses and sedges, but only detailed information is from wintering grounds in Buenos Aires province (Argentina) where preferentially selects wheat, maize, sunflower and sorghum stubbles (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), and Feb, in Tierra del Fuego, where analysis of 250 faeces belonging to either the present species or C. picta found that 79% contained seeds of fleshy-fruited plants and 11% only seeds and fruit-pulp remnants; most (89%) contained remains of digested leaves and 21% only leaves; and five species of seed were passed by geese, of which the most frequently encountered was Empetrum rubrum (Empetraceae), which occurred in almost every seed-bearing faece and often comprised c. 50% of the deposit, with Berberis empetrifolia (Berberidaceae) and Pernettya (Gaultheria) mucronata (Ericaceae) also frequent but usually found in small proportions (3 Willson, M.F., Traveset, A. and Sabag, C. (1997). Geese as frugivores and probable seed-dispersal mutualists. J. Field Orn. 68(1): 144-146. Close ). Feeds by grazing on meadows and rough pasture.

Vocalizations are sexually dimorphic  as in other Chloephaga: male utters soft, wigeon-like whistles, while female gives harsh cackling notes (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ).

Starts Oct/Nov; overall season Nov–Mar in Tierra del Fuego (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). In single pairs or loose groups; nest abundantly lined with down, and placed in tree hollow or on Nothofagus stump usually 1·2–4 m above the ground (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), or in long grass. Clutch 4–6 brown eggs, mean size 72·3 mm × 48·4 mm, mass 89–110 g (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); incubation c. 30 days, by female alone guarded by male (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); chicks have olive-grey or drab brown down with blackish-grey markings, black legs and bill, and hatch weight of 64·3 g (achieves 504 g at 21 days) (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ); fledging period unknown (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Typical brood sizes are 5–6, but due to brood amalgamation may reach 15 (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Probably sexually mature at two years old (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Oldest recorded bird in captivity was 16 years old (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). No other data.

Not globally threatened (Least Concern). Total population unknown, but has been estimated at 25,000–100,000 individuals (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ), although recent austral winter surveys (2011 and 2012) in SE Buenos Aires province, NE Argentina, suggested that as many as c. 150,000 may congregate there at this season (4 Pedrana, J., Bernad, L., Bernardos, J.N., Seco Pon, J.P., Isacch, J.P., Muñóz, S.D. and Maceira, N.O. (2018). Winter population size estimations of three migratory sheldgeese in the southern pampas, Argentina. Waterbirds. 41(1): 16–21. Close ). Considered especially common in Chile; rarer in rest of range; rare in Falklands, and relatively scarce in Tierra del Fuego where 2000–3000 birds counted during breeding season of 1973, and densities of 1·7–3·1, 0·7–2·3 and 0·4–0·7 per km² in Oct, Dec and Jan–Feb, respectively (1 Kear, J., Editor (2005). Ducks, Geese and Swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, UK. Close ). Relatively free from human persecution at breeding grounds, but in winter associates with other, more abundant sheldgeese and suffers the same persecution by farmers due to perceived competition with livestock; possible effects on population should be investigated to prevent risk of significant decline.