Cape Barren Goose (Cereopsis novaehollandiae)

Cape Barren Goose

[order] ANSERIFORMES | [family] Anatidae | [latin] Cereopsis novaehollandiae | [authority] Latham, 1801 | [UK] Cape Barren Goose | [FR] Cereopse cendree | [DE] Huhnergans | [ES] Ganso Cenizo | [NL] Hoendergans

Subspecies

Monotypic species

Genus

The Cape Barren Goose (Cereopsis novaehollandiae) is a large goose resident in southern Australia. The species is named for Cape Barren Island, where specimens were first sighted by European explorers. It is a most peculiar goose of uncertain affiliations (Sraml et al. 1996). It may either belong into the “true geese” and swan subfamily Anserinae or into the shelduck subfamily Tadorninae as distinct tribe Cereopsini, or be separated, possibly including the prehistorically extinct flightless New Zealand Geese of the genus Cnemiornis, in a distinct subfamily Cereopsinae. Indeed, the first bones of the New Zealand birds to be discovered were similar enough to those of the Cape Barren Goose to erroneously refer to them as “New Zealand Cape Barren Goose” (“Cereopsis” novaezeelandiae). The smaller population of Cape Barren Goose in Western Australia is described as a subspecies, Cereopsis novaehollandiae grisea, and named for the group of islands known as the Recherche Archipelago.

Physical charateristics

The Cape Barren goose is pale grey, with black markings near the tips of its wing feathers and tail. It has pink legs and black feet. Its most striking feature is the bright greenish yellow cere on its short black bill.

Listen to the sound of Cape Barren Goose

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

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 150 cm wingspan max.: 190 cm
size min.: 75 cm size max.: 100 cm
incubation min.: 34 days incubation max.: 37 days
fledging min.: 70 days fledging max.: 76 days
broods: 1   eggs min.: 3  
      eggs max.: 6  

Range

Australasia : South Australia. Cape Barren geese are found along the southern coast of Australia from the islands of the Recherche Archipelago in Western Australia, Kangaroo Island and the Sir Joseph Banks Islands of South Australia, the Victorian coastal islands around Wilsons Promontory, and the islands of Bass Strait including the Hogan, Kent, Curtis and Furneaux Groups. A small population is to be found at Cape Portland in Tasmania, and birds have been introduced to Maria Island off Tasmania?s southeast coast and the Hunter group of islands off northwest Tasmania.

Habitat

Cape Barren geese live mostly on small, windswept and generally uninhabited offshore islands, but venture to adjacent mainland farming areas in search of food in summer. Their ability to drink salt or brackish water allows numbers of geese to remain on offshore islands all year round.

Reproduction

Geese lay eggs in nests in the tussocks found in the open grassland areas in which they live. Each pair of geese establishes a territory in autumn, prepares a nest site and defends it noisily and determinedly against other geese. About five eggs are laid and the eggs take about a month to hatch. The goslings develop rapidly during the winter, and by the end of spring are able to fly, fledging takes about 75 days. At this time they join the flocks of non-breeding geese which have also spent the winter on the breeding island. By early summer, the breeding islands dry off and grass ceases to grow. There is generally sufficient feed for the breeding birds to survive the summer, but the non-breeding geese generally leave these small islands and move to larger islands nearby mainland areas where they feed on improved pasture. When the autumn rains come the flocks return to the breeding islands.

Feeding habits

These geese are grazing birds, and eat predominantly the common island tussock Poa poiformis as well as spear grass and various herbs and succulents. They also eat pasture grasses including barley grass and clover.

Video Cape Barren Goose

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

copyright: Nick Talbot


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 may be moderately small to large, but it is not believed to 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.
By the 1950s their numbers were so low that biologists feared they may be close to extinction. Various initiatives have been taken which have increased the goose population to a level no longer considered to be in danger. However, they remain one of the rarest of the world?s geese.
Cape Barren Goose status Least Concern

Migration

Sedentary, with some dispersal after the breeding season. Some remain on the breeding islands others move to the mainland.

Distribution map

Cape Barren Goose distribution range map

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