Fuegian steamer duck (Tachyeres pteneres), also known as the flightless steamer-duck or Magellanic flightless steamer-duck, is a large, flightless duck native to the southern coasts of South America. It belongs to the genus Tachyeres (steamer ducks), named for their habit of thrashing across the water's surface like a paddle steamer when escaping danger or fighting.
Taxonomy and Classification
- Kingdom: Animalia
- Phylum: Chordata
- Class: Aves
- Order: Anseriformes
- Family: Anatidae
- Genus: Tachyeres
- Species: Tachyeres pteneres (Forster, 1844)
Description
The Fuegian steamer duck is the largest of the steamer duck species and one of the heaviest wild ducks in the world. It is a massively built waterfowl:
- Length: 65–84 cm (26–33 in)
- Weight: 3.5–7 kg (7.7–15.4 lb); males average 5.34 kg (11.8 lb), females around 4.2 kg (9.3 lb)
- Wingspan: 85–110 cm (33–43 in) — the wings are too small to allow flight and are instead used as paddles to skim rapidly across the water.
Plumage: Males have a blue-gray head and neck with a paler crown and forehead, a narrow white eye-ring that continues backward as a stripe, and a reddish-brown throat. The abdomen, ventral area, and undertail coverts are white; the tail is gray. Females are darker gray-brown on the head with a dark reddish throat, and may show brown or wine-colored tones on the feathers. Juveniles resemble females but are slightly duller.
The bill is stout and deep-based, bright orange in the southern parts of the range, but orange with a greenish distal patch around Chiloé Island.
Distribution and Habitat
The species inhabits rocky coasts and coastal islands from southern Chile and Chiloé to Tierra del Fuego. During the breeding season, it moves to adjacent sheltered bays and lakes further inland. It is uncommon to fairly common along rocky seacoasts and is not typically found on lakes (unlike the flying steamer-duck).
Behavior and Life History
Breeding: Nesting occurs from September through December, either near water obscured in dense shrubby vegetation or in abandoned penguin nest burrows. Clutches contain 4 to 11 eggs (average 9). The ivory eggs measure approximately 8.2 cm × 5.6 cm (3.2 in × 2.2 in) and weigh around 167 g (5.9 oz). Incubation lasts 28 to 40 days. Young fledge at 120–130 days and are then driven from the parents' territory, forming flocks with other ousted immature birds. Sexual maturity is reached at 2 to 3 years.
Diet: Principally saltwater molluscs, crustaceans, and small fish. During the breeding season, they feed on small snails, insect larvae, amphipods, and isopods.
Temperament: Adult males are known for their extremely aggressive disposition, especially during mating season. They have been reported to attack other waterfowl, and there are accounts of a male placed among other species killing all the other birds with its powerful, spurred wings.
Predators: Eggs and young may be taken by foxes, caracaras, gulls, skuas, and giant petrels. In 2009, a marine otter was observed preying on a chick in Puñihuil. Healthy adults are thought to have no natural predators.
Conservation Status
The Fuegian steamer duck is classified as Least Concern on the IUCN Red List (2018). It is locally common within its range, though its flightlessness makes it vulnerable to habitat disturbance and introduced predators in some areas.
