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Anarhynchus frontalis
– Vulnerable
Taxonomy
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Kingdom:
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ANIMALIA
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Phylum:
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CHORDATA
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Class:
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AVES
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Order:
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CHARADRIIFORMES
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Family:
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CHARADRIIDAE
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Scientific Name:
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Anarhynchus frontalis
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Species Authority:
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Quoy & Gaimard, 1830
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Common Name/s:
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Assessment Information
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Red List Category & Criteria:
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VU C2a(ii) ver 3.1 (2001)
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Year Assessed:
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2006
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Assessor/s:
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BirdLife International
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Evaluator/s:
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Butchart, S. & Pilgrim, J. (BirdLife International Red List Authority)
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Justification:
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This species is listed as Vulnerable because it has a small population, in a single subpopulation, which is undergoing a continuing decline due to habitat degradation and the impacts of introduced predators.
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History:
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| 1988 | - | Lower Risk/least concern (BirdLife International 2004) |
| 1994 | - | Vulnerable (Collar, Crosby and Stattersfield 1994) |
| 2000 | - | Vulnerable (BirdLife International 2000) |
| 2004 | - | Vulnerable (BirdLife International 2004) |
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Geographic Range
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Range Description:
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Anarhynchus frontalis breeds in Canterbury and Otago, South Island, New Zealand. It is found in over 26 riverbeds, but is only common on 10. It winters mainly north of 38°S in the North Island. In the last 40 years, population counts have varied between 3,000 and 5,000 individuals7, probably reflecting the difficulty in surveying the species2, but the current best estimate is 4,500-5,000 birds9. Analysis of wintering flocks indicates a slow decline over the last 40 years8, which is supported by preliminary results from a long-term demographic study2.
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Range Map:
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 (click for detailed map)
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Countries:
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Native:
New Zealand
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Population
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Population Trend:
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Habitat and Ecology
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Habitat and Ecology:
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It breeds on braided riverbeds, and frequents sheltered estuaries and coasts over the non-breeding season. Nests are built within 250 m of running water, and are usually hollows in bare shingle, lined with more than 100 small pebbles2,6. It lays two eggs. Young usually begin to breed at two or three years of age6. Mark-recapture of almost 2,400 birds indicates that many live past 10 years of age1, the average adult life expectancy is c.5.4 years4. Diet comprises mostly mayflies and caddisflies, but is more general when rivers are in flood5.
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System:
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Freshwater
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Threats
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Threats:
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Breeding habitat is deteriorating, primarily from the encroachment of weeds as hydroelectric schemes reduce seasonal flushing of riverbeds6. The extent of predation by stoat Mustela erminea and cats has not been quantified, but is likely to be substantial. The recent illegal introduction of Rabbit Haemorrhagic Disease has resulted in the localised switching of some predators to a diet consisting of more birds. Predation by Kelp Gull Larus dominicanus may pose an increasing threat as it becomes more numerous in association with human activities2. Increasing use of riverbeds for recreational purposes and floods are also threats3,6.
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Conservation Actions
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Conservation Actions:
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Conservation measures underway:
The species was shot for sport until 1940, when it became fully protected6. Research on the impact of predation and prey-switching is being undertaken. Predator control for Black Stilt Himantopus novaezelandiae protection benefits a small proportion of the population2. Project River Recovery carries out habitat restoration and predator research in the McKenzie basin3.
Conservation measures proposed:
Model demographic data to determine population trends2.
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