Phalacrocorax featherstoni 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Suliformes Phalacrocoracidae

Scientific Name: Phalacrocorax featherstoni Buller, 1873
Common Name(s):
English Pitt Shag
Stictocarbo featherstoni ssp. featherstoni (Buller, 1873) — Turbott (1990)
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
Identification information: 63 cm. Medium-sized, slight grey-and-black cormorant. Breeding, black head, rump, tail, thighs. Dark grey upperparts with small black spots over wings, back. Grey underparts. Apple-green facial skin. Double crest on head. Non-breeding, no crest. Yellow facial skin. Paler underparts. Voice Displaying male noisy, female silent.

Assessment Information [top]

Red List Category & Criteria: Endangered C1 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., Bell, B., Bester, A., Hitchmough, R. & Weeber, B.
Facilitator/Compiler(s): Benstead, P., Harding, M., Mahood, S., McClellan, R., Pilgrim, J., Taylor, J.
This species is listed as Endangered because it has a very small population which has declined moderately rapidly over the last two generations (18 years), a decline which is predicted to continue given current threats.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Phalacrocorax featherstoni is found in the Chatham Islands, New Zealand, on Chatham, Pitt, Mangere, Little Mangere, South East (= Rangatira), Star Keys, the Pyramid, Big and Middle Sister, Murumurus, the Castle and Rabbit Islands (Marchant and Higgins 1990, Imber 1994, Taylor 2000). The population has been variously estimated at c.500 pairs, fewer than 1,000 pairs (Heather and Robertson 1997) and in 1997-1998, at 729 pairs, following a complete census over the entire breeding range (Bell and Bell 2000). However, new information suggests that the population has declined by 25% over six years from 1997 to 2003, with 547 pairs counted in the second complete census over the 2003-2004 breeding season (Bester and Charteris 2005). The species's foraging range is assumed to be up to 24 km offshore (cf. New Zealand King Shag P. carunculatus).

Countries occurrence:
New Zealand
Additional data:
Estimated area of occupancy (AOO) - km2:22Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:13400
Continuing decline in extent of occurrence (EOO):UnknownExtreme 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
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:A total of 547 pairs (=1,094 mature individuals; 1,400 estimated total individuals) were counted in the second complete census over the 2003-2004 breeding season.

Trend Justification:  The species's population has declined by 25% over six years from 1997 to 2003 (A. Bester per R. Hitchmough in litt. 2005).

Current Population Trend:Decreasing
Additional data:
Number of mature individuals:1094Continuing decline of mature individuals:Yes
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
No. of individuals in largest subpopulation:1-89

Habitat and Ecology [top]

Habitat and Ecology:It nests in small colonies of between five and 20 pairs, on rocky shores and islets, headlands and cliffs. Breeding distribution is limited by suitable nesting sites (Marchant and Higgins 1990). It feeds primarily on small fish, supplemented by marine invertebrates (Heather and Robertson 1997).

Systems:Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat:Unknown
Generation Length (years):8.7
Movement patterns:Not a Migrant

Threats [top]

Major Threat(s): The effects of introduced species on Chatham and Pitt Islands are not known, with birds tending to nest in inaccessible sites. Some nests, however, could be affected by stock, feral cats, pigs, dogs, black rats Rattus rattus, brown rats R. norvegicus and Weka Gallirallus australis (Taylor 2000). Birds are sometimes illegally shot by fishermen (Heather and Robertson 1997, Taylor 2000). A total of 40-80 birds may be caught in crayfish pots annually (Bell and Bell 2000). Recent declines may be a response to changes in the marine environment that are affecting food supplies (Bester and Charteris 2005). The species is potentially threatened by climate change because it has a geographically bounded distribution: it is restricted to an island or islands with a maximum altitude of 283 m (Birdlife International unpublished data).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
In 1961, sheep and cattle were removed from South East Island and, in 1968, sheep were taken off Mangere Island (Taylor 2000).

Conservation Actions Proposed
Census the entire adult population once a suitable methodology has been developed, and at 10-year intervals thereafter, and monitor two accessible colonies annually to determine trends (Taylor 2000). Assess the impact of rock lobster fishing practices (B. Weeber in litt. 2000). Remove feral cats and G. australis from Pitt Island if agreement is reached with residents, and remove sheep, cattle and pigs from parts of Pitt and Chatham Islands that are suitable for colonies. Fence colonies (with owners' permission) if stock are found to be impacting on colonies (Taylor 2000).

Citation: BirdLife International. 2016. Phalacrocorax featherstoni. The IUCN Red List of Threatened Species 2016: e.T22696907A93592062. . Downloaded on 24 November 2017.
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