Poliocephalus rufopectus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Podicipediformes Podicipedidae

Scientific Name: Poliocephalus rufopectus Gray, 1843
Common Name(s):
English New Zealand Grebe, New Zealand Dabchick
Taxonomic Source(s): Turbott, E.G. 1990. Checklist of the Birds of New Zealand. Ornithological Society of New Zealand, Wellington.
Identification information: 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.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Bell, B., Owen, K., Robertson, H. & Taylor, G.A.
Facilitator/Compiler(s): Benstead, P., Mahood, S., McClellan, R., Pilgrim, J., Taylor, J. & Ashpole, J
This species is classified as Near Threatened because it has a very small population which is estimated to approach the threshold for Vulnerable under criterion D1. The population is fragmented but no longer thought to be in continuing decline.

Previously published Red List assessments:

Geographic Range [top]

Range Description:This species 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.

Countries occurrence:
New Zealand
Additional data:
Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:252000
Continuing decline in extent of occurrence (EOO):YesExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:11-100Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Upper elevation limit (metres):800
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population: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.). In the Rotorua Lakes area (which holds one quarter to one third of the total population) the population increased by 57% from 364 individuals in 1985 to 572 individuals in 2011 (Sachtleben et al. 2014). The overall population was precautionarily suspected to be in decline owing primarily to habitat loss and modification and the impacts of human disturbance and introduced predators, however there is evidence to suggest that it may now be stable or even increasing (K. Owen in litt. 2012).
Current Population Trend:Unknown
Additional data:
Number of mature individuals:1200-1400Continuing decline of mature individuals:No
Extreme fluctuations:NoPopulation severely fragmented:No
No. of subpopulations:2-100Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and 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.

Systems:Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):5.3
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): 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, Sachtleben et al. 2014). The species is intolerant of disturbance by people on foot (Sachtleben et al. 2014). 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 [top]

Conservation Actions: Conservation and Research 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 et al. 2014).

Conservation and Research 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).

Citation: BirdLife International. 2016. Poliocephalus rufopectus. The IUCN Red List of Threatened Species 2016: e.T22696592A93572730. . Downloaded on 26 September 2018.
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