Falkland steamerduck (Tachyeres brachypterus)

Description

Falkland steamerduck fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Falkland steamerduck description

The Falkland steamerduck (Tachyeres brachypterus) is a large, flightless waterbird, named for its habit of using the wings and feet to propel itself across the surface of the water in a manner reminiscent of an old paddle steamer ^{(3) (4) (5)}. Its scientific name, brachypterus, means ‘short winged’ ⁽⁴⁾, referring to the fact that its wings are shorter than its body ^{(3) (6)}.

Both the male and female Falkland steamerduck have a largely greyish-brown body with brownish edges to the feathers, which give a scalloped appearance ⁽⁴⁾. The breast, sides and flanks show some chestnut, while the lower breast, belly, wing linings and secondary feathers are white ⁽⁴⁾. The legs and feet are orange-yellow. Both sexes have a white eye ring and a curving white stripe behind the eye, although the stripe may be less conspicuous in males ^{(3) (4) (5) (6)}.

The male Falkland steamerduck has a pale greyish head and neck, with darker patches on the cheeks, and a bright orange bill with a dark tip. The head may become whiter with age. The female is smaller than the male and slightly darker overall, with a browner head and a greenish-yellow bill ^{(3) (4) (5) (6)}. The sexes can also be told apart by their calls, the male giving a loud, two-note whistle while the female gives grunting and creaking calls ⁽³⁾. Juvenile Falkland steamerducks resemble the adult female, but have a greyish bill, yellow-brown legs and feet, and lack the white stripe behind the eye ^{(2) (3)}.

This species can be difficult to tell apart from the flying steamerduck (Tachyeres patachonicus), the only other steamerduck within its range. However, the flying steamerduck is more slender than the Falkland steamerduck and, as its name suggests, it can fly ^{(3) (6)}.

Also known as

Falkland flightless steamer duck, Falkland flightless steamerduck, Falkland flightless steamer-duck, Falkland steamer duck, Falkland steamer-duck, logger, logger duck, loggerhead, sea logger.

Synonyms

Anas brachyptera, Anas cinerea, Tachyeres brachydactyla.

Size

Length: 61 - 74 cm ^{(2) (3)}

Wingspan: 84 - 94 cm ⁽³⁾

Weight

3.4 - 4.4 kg ⁽²⁾

Falkland steamerduck biology

The diet of the Falkland steamerduck consists mainly of marine molluscs, such as mussels, limpets and sea snails, and crustaceans such as crabs and shrimps ^{(2) (3) (4) (5) (6)}. The shells of its prey are crushed in the powerful beak ⁽⁵⁾. The Falkland steamerduck upends to feed in shallow water, or dives, using the wings and feet to propel itself underwater ^{(2) (4) (5) (6)}. It may also search for food along the water’s edge, and its feeding activity is strongly associated with the tides ⁽⁴⁾.

Although the Falkland steamerduck may nest at any time of year, most breeding takes places between September and December. The nest is built close to water, usually amongst vegetation or in an abandoned penguin burrow ^{(2) (4) (5) (6)}. It consists of a shallow depression, lined with feathers and sometimes strengthened with sticks or grass ^{(4) (6)}. The female alone incubates the clutch of 4 to 11 eggs, which hatch after around 34 days ^{(2) (4)}, but the male helps care for the chicks and defends them aggressively ⁽⁵⁾. Young Falkland steamerducks fledge after about 12 weeks ^{(2) (4)}, and females have been recorded breeding for the first time in their second year ⁽⁴⁾. In captivity, this species has lived for up to 20 years ⁽⁴⁾.

The Falkland steamerduck is a highly aggressive and territorial species, and pairs defend a section of coastline year-round, not only against other steamerducks but also against any intruding bird species ^{(4) (6) (8)}. Territorial disputes can be bloody, the combatants using well-developed spurs on the wings to fight, and injuries are common ^{(6) (8)}. Immature and non-breeding individuals often congregate in large flocks away from established territories ^{(3) (4) (6)}.

This species’ chicks are vulnerable to predators such as gulls and skuas, but adult Falkland steamerducks have no natural enemies apart from sea lions ^{(2) (4) (6)}. As it is flightless, the Falkland steamerduck can only escape by diving or by ‘steaming’ ⁽³⁾, but the short wings are surprisingly powerful and, together with its large feet, are well suited to moving this heavy duck over the water ^{(5) (9)}.

Falkland steamerduck range

The Falkland steamerduck is endemic to the Falkland Islands, in the south-west Atlantic Ocean ^{(2) (3) (4) (5) (7)}.

Falkland steamerduck habitat

This species inhabits rugged shorelines along the coast, where it is common on rocky headlands, small islands and in sheltered bays ^{(2) (3) (4) (7)}. The Falkland steamerduck does not use freshwater habitats far inland, but will walk or swim to freshwater pools near the coast ^{(3) (4)}.

Falkland steamerduck status

The Falkland steamerduck is classified as Least Concern (LC) on the IUCN Red List ⁽¹⁾.

Falkland steamerduck threats

The Falkland steamerduck is widespread and common along the coastlines of the Falkland Islands, and is not known to face any major threats ^{(2) (3) (7)}. Steamerducks are not considered edible, so this species is not affected by hunting ^{(5) (8)}. However, it may be at some risk from coastal pollution, such as from oil spillages and sediment run-off, which can smother the shellfish beds on which its feeds ^{(3) (4) (6)}.

Falkland steamerduck conservation

There are no specific conservation measures currently targeting the Falkland steamerduck. However, a range of conservation initiatives are underway in the Falkland Islands, including habitat restoration and the control and eradication of invasive species. In particular, the Falkland steamerduck may benefit from efforts to clean up beaches and to assess the impacts of oil exploration activities ⁽⁶⁾.

ARKive is supported by OTEP, a joint programme of funding from the UK FCO and DFID which provides support to address priority environmental issues in the Overseas Territories, and Defra

Find out more

Find out more about the Falkland steamerduck:

• BirdLife International:
  http://www.birdlife.org/datazone/speciesfactsheet.php?id=406

Find out more about conservation in the Falkland Islands:

• Falklands Conservation:
  http://www.falklandsconservation.com/
• UK Overseas Territories Conservation Forum - The Falkland Islands:
  http://www.ukotcf.org/territories/falkland.htm

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Glossary

Crustaceans

Diverse group of animals with jointed limbs and a hard chitinous exoskeleton, characterised by the possession of two pairs of antennae, one pair of mandibles (mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, woodlice and barnacles.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Incubate

To keep eggs warm so that development is possible.

Molluscs

A diverse group of invertebrates, mainly marine, that have one or all of the following; a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.

Secondary feathers

The shorter flight feathers projecting along the inner edge of a bird’s wing.

Territorial

Describes an animal, a pair of animals or a colony that occupies and defends an area.

Territory

An area occupied and defended by an animal, a pair of animals or a colony.

References

1. IUCN Red List (February, 2011)
   http://www.iucnredlist.org/
2. del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Lynx Edicions, Barcelona.
3. Ogilvie, M.A. and Young, S. (2002) Photographic Handbook: Wildfowl of the World. New Holland Publishers, London.
4. Kear, J. (2005) Ducks, Geese and Swans. Volume 1: General Chapters, and Species Accounts (Anhima to Salvadorina). Oxford University Press, Oxford.
5. Roots, C. (2006) Flightless Birds. Greenwood Publishing Group, Connecticut.
6. Falklands Conservation (February, 2011)
   http://www.falklandsconservation.com/
7. BirdLife International (February, 2011)
   http://www.birdlife.org/datazone/speciesfactsheet.php?id=406
8. Livezey, B.C. and Humphrey, P.S. (1985) Territoriality and interspecific aggression in steamer-ducks. The Condor, 87(1): 154-157.
9. Livezey, B.C. and Humphrey, P.S. (1986) Flightlessness in steamer-ducks (Anatidae: Tachyeres): its morphological bases and probable evolution. Evolution, 40(3): 540-558.