The New Zealand grebe (''Poliocephalus rufopectus''), also known as the New Zealand dabchick or weweia, is a member of the

grebe Grebes () are aquatic diving birds in the order (biology), order Podicipediformes (). Grebes are widely distributed freshwater birds, with some species also found in sea, marine habitats during Bird migration, migration and winter. Most grebes f ...

family

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

Taxonomy

''Poliocephalus rufopectus'' is an aquatic diving bird in the

order. ''Poliocephalus rufopectus'' (G.R.Gray) was originally described by the English ornithologist

George Robert Gray George Robert Gray (8 July 1808 – 6 May 1872) was an English zoology, zoologist and author, and head of the Ornithology, ornithological section of the British Museum, now the Natural History Museum, London, Natural History Museum, London f ...

as ''Podiceps rufopectus'' G.R.Gray, 1843 (in

subgenus In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ...

''Poliocephalus''). The type specimen was collected by British botanist and scientific collector

Andrew Sinclair Andrew Annandale Sinclair FRSL FRSA (21 January 1935 – 30 May 2019) was a British novelist, historian, biographer, critic, filmmaker, and a publisher of classic and modern film scripts. He has been described as a "writer of extraordinary flu ...

in New Zealand. ''P. rufopectus'' is one of two species in the genus ''Poliocephalus,'' with the other being the

hoary-headed grebe The hoary-headed grebe (''Poliocephalus poliocephalus'') is a member of the grebe family. It breeds in southern parts of Australia; it winters throughout the island of Tasmania. The bird takes its name from the silvery-white streaking on its blac ...

(''Poliocephalus poliocephalus'') which is native to Australia.

Description

The New Zealand grebe has dark brown plumage, a small black head with fine silver feathers, a black pointed bill and characteristic yellow eyes. It grows to about , and weighs about . Non-breeding individuals have a paler plumage and females tend to be a bit lighter, smaller and have a slightly shorter bill than males.

Distribution and habitat

This grebe species inhabits mainly shallow freshwater lakes, ponds and sheltered inlets. Currently it is found mainly in the

North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...

, where it is well distributed on the coastal lakes of the West coast from North Cape to Pukekohe and from Taranaki to Paraparaumu, as well as on ponds of the

Volcanic Plateau A volcanic plateau is a plateau produced by volcanic activity. There are two main types: lava plateaus and pyroclastic plateaus. Lava plateau Lava plateaus are formed by highly fluid basaltic lava during numerous successive eruptions thro ...

, Gisborne, Hawkes Bay and the Wairarapa. Formerly this species was also present in the lowland lakes of the

South Island The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...

,Andrew Crowe, ''"Which New Zealand Bird?"'', Penguin, 2001 but underwent a rapid decline, for unknown reasons, in the 19th century – the last regular breeding record in the South Island was in 1941.Barrie Heather and Hugh Robertson, ''"The Field Guide to the Birds of New Zealand (revised edition)"'', Viking, 2005 In 2012 a pair bred near Takaka for the first time in recent history.

Behaviour

These freshwater diving birds usually fly only at night, whilst during the day, they are always found in the water, swimming on the surface and frequently diving to feed. Thus, if they are in danger or get disturbed at daytime they do not flee by flying, but swimming or diving away. During autumn and winter, they are found forming flocks, while during the breeding season they are mostly seen in monogamous pairs. They show aggressive territorial behaviour towards intruders and the otherwise silent species give short calls throughout the breeding season and when in danger.

Diet

Their diet consists mostly of aquatic insects and their larvae, as well as small molluscs such as freshwater snails. Bigger prey such as fish and freshwater crayfish are sometimes eaten too. Thus, their bill, being short and pointed, is adapted to their mainly invertebrate diet. They catch their prey during dives and feeding underwater or pick it from the water surface.

Breeding

A dabchick with her young chick nestled in amongst her feathers 01

New Zealand grebe at Queen Elizabeth Park - MC 03

The breeding season is from June to March. On average 2–3 eggs are laid and incubated 22–23 days by both female and male, in a nest. The nest is mostly made out of surrounding vegetation, including floating plant material. Hatched chicks are

precocial Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

, although being flightless for the first few weeks they can swim and dive. Both parents assist in rearing and feeding their young for up to 70 days after hatching. Until the adult plumage develops, the chick has irregular striped markings on head and neck and the bill is black.

Conservation

This species is

to New Zealand and is nowadays only found in the North Island. In 1994, the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

classified the New Zealand grebe as Endangered, but due to conservation actions including habitat management, its population has recently increased to around 1,900–2,000 birds and was reclassified as Near Threatened in 2016, and to least concern in 2022. Human activity currently has a net benefit as artificial habitat, including farm dams and ponds formed for stock water supplies, increases the area of occupation for the grebes. So, although the population is still quite small it is thought to no longer be in decline.

References

External links

* ''Poliocephalus rufopectus'' discussed on

RNZ Radio New Zealand (), commonly known as RNZ or Radio NZ, is a New Zealand public service broadcaster and Crown entity. Established under the Radio New Zealand Act 1995, it operates news and current affairs station, RNZ National, and a classica ...

Critter of the Week ''Critter of the Week'' is a weekly RNZ National programme about endangered and neglected native plants and animals of New Zealand. Beginning in 2015, ''Critter of the Week'' is an approximately 15-minute discussion between Nicola Toki (origi ...

''
22 March 2024

New Zealand dabchick
at New Zealand Birds Online {{Authority control Endemic birds of New Zealand Podicipedidae Poliocephalus Birds described in 1843 Taxa named by George Robert Gray