Kelp Goose (Chloephaga hybrida)

[order] ANSERIFORMES | [family] Anatidae | [latin] Chloephaga hybrida | [authority] Molina, 1782 | [UK] Kelp Goose | [FR] Ouette marine | [DE] Kelpgans | [ES] Cauquen Caranca | [NL] Kelpgans

Subspecies

Genus

Physical charateristics

Male kelp geese are the only entirely white waterfowl except for swans; and unlike any swans, they have yellow legs and feet and a short, black bill with a crimson spot on the culmen. Females have dark brown heads with a white eye-ring, heavily barred breasts and flanks, and a dark brown mantle, with a white tail and tail coverts. The wing pattern of females is like that of the other typical sheldgeese, rather than white as in males. Juvenile and immature males are rather like the female but have brown secondary coverts and dull greenish yellow legs and feet, and young females have dark upper tail coverts. In the field, the entirely white plumage of the adult male is unmistakable, and females appear generally dark except for their white hindquarters. The call of the male is a repeated whistle, that of females a raucous snarling note.

Listen to the sound of Kelp Goose

[audio:http://www.planetofbirds.com/MASTER/ANSERIFORMES/Anatidae/sounds/Kelp Goose.mp3]

Copyright remark: Most sounds derived from xeno-canto

recorded by Andrew Spencer

Range

South America : South

Habitat

The habitat of kelp geese consists of rocky shorelines and shingle beaches. Occasionally the birds visit fresh-water ponds for bathing and drinking. Nesting also occurs near fresh-water areas less than a kilometer from the coast.

Reproduction

Nesting gets under way on the Guaitecas Islands of southern Chile in November but begins appreciably earlier on the Falklands, with most nesting in late October and early November. Nests are almost always placed within ten yards of the high-tide line, often on low cliff ledges, in clumps of tall tussock grasses, or even under old planks on the beach. Ledges from four to eight feet up a cliff, with a cover of stunted tussock grass, are favorite locations. The nest is lined with vegetation and gray down, and the normal clutch size ranges from 3 to 7 eggs, with 6 the most commonly encountered number. The incubation period is 30 days, and the conspicuous male remains close by throughout the period, thus often revealing the nest’s location. The adaptive significance of the male’s white coloration is obscure, but may be related to its effectiveness as a dominance signal in territorial encounters. Territorial defense of limited shoreline food resources may be a significant factor in maintaining the fairly low population densities of the bird. Upon hatching, the goslings are quickly led to water and feed, during the low-tide periods of each day, mainly on algae of the filamentous (Enteromorpha) type. This restricted foraging period probably accounts for their slow growth rate; The fledging period is 12 to 13 weeks, compared to 9 or 10 in the upland goose. The flightless period of adults extends from late November through February on the Falkland Islands.

Feeding habits

Foraging is restricted largely to filamentous algae (Enteromorpha), sea lettuce (Ulva), and leafy algae (Porphyra) growing on tidal rocks. When nesting, adults also consume green grasses near the nests, and in winter the berries of “diddle-dee” (Empetrum) may be an important food. Young birds apparently eat much the same foods as adults, with animal materials only a very minor component.

Video Kelp Goose

httpv://www.youtube.com/watch?v=DX01XF6Yv84

copyright: Laurent Demongin

Conservation

This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
There are currently no significant threats to the kelp goose, and the population is large and stable. The only potential risk for this species is a major oil spillage in adjacent seas.

Migration

The Falkland Island population is essentially sedentary, with only local movements during winter, leaving breeding areas in March and April, and returning in September
and October. The continental population undertakes small-scalle northward migrations during winter along the Chilean and Argentinean coast.

Distribution map