Paradise Shelduck

Identification

The paradise shelduck is a colourful, large-bodied species of duck that differs in features depending on the sex. Both females and males have chestnut-colour undertails, primarily black wing feathers with green secondary wing feathers, and upper wing surface feathers that are white. They have black legs and webbed feet for swimming. Paradise shelducks are the largest of the Tadorna species, measuring 63 to 71 cm (25 to 28 in) in length and between 1.09 and 2 kg (2.4 and 4.4 lb) in weight, averaging 1.72 kg (3.8 lb) in males and 1.29 kg (2.8 lb) in females, with a wingspan of around 90 centimetres (35 in).<p>The adult male has a blue-black head and neck, with a black rump and tail; the back and flank are lightly flecked with a pale yellow colour. The wings of males have contrasting white upper-coverts and black remiges, metallic green speculum feathers, and rusty brown tertials feathers. The male also has a dark grey flecked with pale-yellow breast and abdomen, chestnut undertail and underwing, and black iris, bill, legs, and feet. The female, unlike the male, has an entirely white head and neck with a dark grey back heavily flecked with pale yellow. The rest is very similar to the male with the female's body being dark or light chestnut depending on age and stage of molting.<p>The downy young are white with a brown crown and brown stripes from crown to tail. Juvenile males look much like the adult males, but the females are smaller with a white patch at the base of the bill. The females assume their white head during the first molt and 1–2 months after fledging their breast and abdomen turn dark chestnut.<p>The vocal calls differ from male to female. The male belts a di-syllabic honk like a goose when in flight or when alarmed. The male gives off a deep zonk-zonk honk, while the female is characterised by a penetrating zeek-zeek.<p>Male and fledgling paradise shelducks can be confused with the vagrant Australian shelduck which has a similar size, shape, and posture when swimming, on land, and when in flight. However, paradise shelducks lack the white collar, white parts around the eye and base of the bill, and the chestnut-coloured breast band.

Taxonomy

The paradise shelduck was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with all the other ducks, swans, and geese in the genus Anas and coined the binomial name Anas variegata. Gmelin based his description on the "Variegated goose" from New Zealand that had been described in 1785 by the English ornithologist John Latham in his A General Synopsis of Birds. The naturalist Joseph Banks had provided Latham with a water-colour drawing of the duck by Georg Forster who had accompanied James Cook on his second voyage to the Pacific Ocean. The picture of a female bird was drawn in April 1773 at Dusky Sound, a fiord on the southwest corner of New Zealand. This picture is now the holotype for the species and is held by the Natural History Museum in London. The paradise shelduck is now placed with five other species in the genus Tadorna that was introduced by the German zoologist Friedrich Boie in 1822. The genus name comes from the French word Tadorne for the common shelduck. The specific epithet variegata is from the Latin variegatus meaning "variegated". The species is monotypic: no subspecies are recognised. Other common names include painted duck, pari, parry, parrie, and pūtangitangi in Māori.

Scientific name

Tadorna variegata

Authority

(Gmelin, JF, 1789)

Order

Anseriformes

Family

Anatidae

Genus

Tadorna

Range and habitat

Paradise shelducks are the most widely distributed waterfowl in New Zealand. They inhabit the North Island, South Island, offshore islands such as Little Barrier Island, Kapiti Island, Great Barrier Island, and Stewart Island. They are most numerous in the North Island, Hawkes Bay, Poverty Bay, Taranaki and in Tongariro National Park, while scattered populations are present in Waikato and Wellington. Paradise Shelducks are uncommonly found on the Canterbury Plains, and generally not found in the high parts of the mountains.<p>Their preferred habitat is pasture, tussock grassland, and wetlands both on the mainland and on offshore islands. They are common around the hilly farmland characterised by fertile riversides, farm dams, and natural pools of the North Island. On the South Island, they can commonly be found in the tussock river valleys and high-country lakes while a small number can be found in the mountain streams, coastal flats, and brackish inlets. Around water bodies are the preferred breeding habitat for which to use as a nursery area for young, the quality or depth of water does not influence the selection, but available vantage points with long views to or from water do influence the selection. Many chosen places have a grassland at the edge of the water and a cover for refuges which is dense, such as reedbeds and forest. This has the purpose of the birds being able to feed close to the water's safety, and lakes surrounded by dense vegetation might be chosen as well to feed at night.

Migration

Resident species

Behavior

Migration pattern: Resident species.

Conservation

Population trend: stable.

Population trend

stable