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Charadrius obscurus
– Endangered
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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Charadrius obscurus
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Species Authority:
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Gmelin, 1789
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Common Name/s:
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| English | — | NEW ZEALAND DOTTEREL |
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Assessment Information
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Red List Category & Criteria:
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EN C2a(i) 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 has a very small, severely fragmented population and a small overall range. The certain extirpation of the southern subspecies has been averted due to extensive predator control, and numbers are now gradually increasing. However, the status of the northern subspecies is uncertain and populations in some areas have undergone substantial declines. The species is therefore listed as Endangered.
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History:
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| 1988 | - | Lower Risk/least concern (BirdLife International 2004) |
| 1994 | - | Endangered (Collar, Crosby and Stattersfield 1994) |
| 2000 | - | Vulnerable (BirdLife International 2000) |
| 2004 | - | Vulnerable (BirdLife International 2004) |
| 2005 | - | Endangered (BirdLife International 2005) |
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Geographic Range
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Range Description:
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Charadrius obscurus is endemic to New Zealand. Subspecies obscurus is restricted when breeding to Stewart Island, but formerly occurred on the South Island3. On Stewart Island, it declined as much as 80% in c.40 years, numbering 62 birds in 1991-19924, but recovering to 111 birds in 1997 and 150 in 19996,8. In 2004 the population was estimated to be 200 and increasing10. Subspecies aquilonius breeds in the northern North Island. The population was estimated at 1,313 birds in 1989, and at 1,452 in 1996, but is likely to have declined since then as population increases at managed sites are likely to have been offset by declines elsewhere. The current population status is management-dependent, and significant declines would begin immediately if intensive management stopped10.
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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 (North Is., South Is.)
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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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On the North Island, it usually breeds on wide ocean beaches, estuaries and harbours with tidal mudflats7. On Stewart Island, it breeds inland, usually at high altitudes on bare hilltops and open bog or tussock-grasslands6. It lays three eggs. It feeds mostly on terrestrial and aquatic invertebrates. Young generally begin to breed in their second year. The oldest recorded bird lived to at least 31 years of age7.
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System:
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Freshwater
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Threats
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Threats:
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Introduced predators were the primary cause of extinction on the South Island3. They remain the greatest threat on the North Island - one study indicated that 60% of nests were lost to predators2. Feral cats caused the rapid decline on Stewart Island4. On the North Island, housing developments and encroachment by dune-stabilising weeds reduce habitat, and stock, human, dog and vehicle disturbance reduces breeding success1,9. Storms and very high tides can cause nest failures6,11.
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Conservation Actions
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Conservation Actions:
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Conservation measures underway:
On the North Island, nest protection by predator trapping, gull control, signs and wardens have caused local improvements in breeding success - 20% of c.600 breeding pairs were managed in 1998-19995. On Stewart Island, cats and rodents are intensively controlled in four important breeding sites6. Captive-breeding trials with aquilonius have been undertaken in case the technique is required for obscurus2. Chicks have been raised successfully6.
Conservation measures proposed:
Complete full census every five to seven years. Monitor breeding and flocking sites. Continue research and experimental management of both subspecies. Continue practical protection of key sites. Obtain statutory protection of selected breeding sites. Increase public awareness1.
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