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VU
New Zealand Grebe Poliocephalus rufopectus

Justification
This species is considered Vulnerable because it has a very small and fragmented population, which is probably declining overall.

Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Turbott, E. G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.

Identification
29 cm. Small, dark grebe. Blackish head with fine, silver feathers. Pale yellow eye. Dark, chestnut foreneck and breast. Black-brown upperparts. Paler non-breeding plumage. Similar spp. Hoary-headed Grebe P. poliocephalus is lighter and less red. Australian Little Grebe Tachybaptus novaehollandiae is smaller. Voice Silent except for chattering calls in breeding season.

Distribution and population
Poliocephalus rufopectus is endemic to New Zealand. The remaining population is restricted to North Island with a wide but fragmented distribution. Occasional vagrants have appeared in the north of South Island since the late 1980s. In 2012, a pair bred near Takaka, representing the first confirmed breeding record on South Island since 1941 (K. Owen in litt. 2012). The national population has been estimated to number 1,900-2,000 birds, including c.200 in Northland, c.700 in the Volcanic Plateau, c.400 in the Hawkes Bay, c.150 in Wairarapa and c.400 in Manawatu (Heather and Robertson 1997, Sachtleben in prep.). Numbers appear to be stable or increasing in some parts of its range (Marchant and Higgins 1990, Sachtleben in prep.), but the population is precautionarily suspected to be in decline overall, owing to continued threats. The reason for the rapid decline and extinction on South Island in the 19th century is not known.

Population justification
The population has been estimated at c.1,900-2,000 birds (Heather and Robertson 1997, Sachtleben in prep.), thus the number of mature individuals is put at 1,200-1,400, based on the assumption that mature individuals account for around 2/3 of the total population.

Trend justification
The species appears to be stable or increasing in some parts of its range (Marchant and Higgins 1990, Sachtleben in prep.), but the overall population is precautionarily suspected to be in decline owing primarily to habitat loss and modification and the impacts of human disturbance and introduced predators.

Ecology
It inhabits small bodies of freshwater such as sand-dune lakes and lagoons and larger inland lakes with shallow, sheltered inlets (Marchant and Higgins 1990, Heather and Robertson 1997). It also uses "artificial" habitats such as farm ponds and dams and oxidation ponds. It usually builds its nest on emergent vegetation at the water's edge, floating but attached to vegetation or overhanging branches; as such, it is easily broken up by wave motion or swamped (Marchant and Higgins 1990). It feeds predominantly on aquatic invertebrates, mostly insects and larvae, but sometimes fish and freshwater crayfish (Heather and Robertson 1997). Little is known about the species's life history or population dynamics.


Threats
Threats include the drying of dune lakes, destruction of nesting habitat, increasing vegetation, increased human activity on waterways, especially boat traffic, and predation by introduced rats Rattus spp. and mustelids Mustela spp., especially when nesting (Marchant and Higgins 1990, G. A. Taylor in litt. 1994). Nests are prone to boat wash caused by recreational boating, which occurs on many occupied lakes during the breeding season (K. Owen in litt. 2012). Low breeding success is achieved on large waters, possibly owing to fluctuating water-levels, wave action and disturbance by other species. Breeding success on dune lakes, farm dams and the sheltered arms of lakes appears to be higher (Marchant and Higgins 1990, K. Owen in litt. 2012), and increases in the number of water storage dams may be driving increases in this species's population in some areas (K. Owen in litt. 2012).


Conservation Actions Underway
Infrequent, region-wide surveys have been undertaken to monitor some key population changes, e.g. the five-yearly census of the Rotorua lakes population (Sachtleben in prep.). Predator control operations since c.2002 have included the use of bait stations to control numbers of brown rats Rattus norvegicus around the shoreline of Lake Tarawera at the Tarawera settlement, which has led to a doubling of the local P. rufopectus population (Sachtleben in prep.).
Conservation Actions Proposed
Regularly monitor population changes throughout its range. Carry out research into the species's life history and population dynamics (K. Owen in litt. 2012). Quantify the effects of introduced predators on breeding success. Consider reintroductions to the South Island (B. D. Bell in litt. 1999).


References
Heather, B. D.; Robertson, H. A. 1997. The field guide to the birds of New Zealand. Oxford University Press, Oxford, UK.

Marchant, S.; Higgins, P. J. 1990. Handbook of Australian, New Zealand and Antarctic birds, 1: ratites to ducks. Oxford University Press, Melbourne.

Text account compilers
Benstead, P., Mahood, S., McClellan, R., Pilgrim, J., Taylor, J.

Contributors
Bell, B., Owen, K., Robertson, H., Taylor, G.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2014) Species factsheet: Poliocephalus rufopectus. Downloaded from http://www.birdlife.org on 22/07/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 22/07/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - New Zealand dabchick (Poliocephalus rufopectus) 0

Key facts
Current IUCN Red List category Vulnerable
Family Podicipedidae (Grebes)
Species name author Gray, 1843
Population size 1200-1400 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 87,500 km2
Country endemic? Yes
Links to further information
- Additional Information on this species