Anarhynchus frontalis

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	CHARADRIIFORMES	CHARADRIIDAE

Scientific Name:

Anarhynchus frontalis

Species Authority:

Quoy & Gaimard, 1830

Common Name/s:

English

–

Wrybill

Assessment Information [top]

Red List Category & Criteria:

Vulnerable C2a(i) ver 3.1

Year Published:

2008

Assessor/s:

BirdLife International

Reviewer/s:

Mahood, S., Butchart, S.

Contributor/s:

Dowding, J., Grant, A.

Justification:
This species is listed as Vulnerable because it has a small population, in a single subpopulation, which is undergoing a continuing decline owing to habitat degradation and the impacts of introduced predators.

History:

2006	–	Vulnerable
2004	–	Vulnerable
2000	–	Vulnerable
1996	–	Vulnerable
1994	–	Vulnerable

Geographic Range [top]

Range Description:	Anarhynchus frontalis breeds in Canterbury and Otago, South Island, New Zealand. It is found on 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.
Countries:	Native: New Zealand
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	Riegen and Dowding (2003)
Population Trend:	Decreasing

Habitat and Ecology [top]

Habitat and Ecology:	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 pebbles^2,6. 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.
Systems:	Freshwater; Marine

Habitat and Ecology:

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 pebbles^2,6. 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.

Systems:

Freshwater; Marine

Threats [top]

Major Threat(s):	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, perhaps especially in the non-breeding season¹⁰. The recent illegal introduction of Rabbit Haemorrhagic Disease has resulted in the localised switching of some predators to a diet containing proportionately 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 threats^3,6.

Major Threat(s):

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, perhaps especially in the non-breeding season¹⁰. The recent illegal introduction of Rabbit Haemorrhagic Disease has resulted in the localised switching of some predators to a diet containing proportionately 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 threats^3,6.

Conservation Actions [top]

Conservation Actions:	Conservation Actions 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 Actions Proposed Model demographic data to determine population trends². Continue to monitor wintering aggregations. Control introduced predators and invasive plants at important sites. Control the recreational use of riverbeds, perhaps by delimiting areas where humans are excluded.

Conservation Actions:

Conservation Actions 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 Actions Proposed
Model demographic data to determine population trends². Continue to monitor wintering aggregations. Control introduced predators and invasive plants at important sites. Control the recreational use of riverbeds, perhaps by delimiting areas where humans are excluded.

Citation:	BirdLife International 2008. Anarhynchus frontalis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 24 May 2012.
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