Phalacrocorax carunculatus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Suliformes Phalacrocoracidae

Scientific Name: Phalacrocorax carunculatus
Species Authority: (Gmelin, 1789)
Common Name(s):
English Rough-faced Shag, Rough-faced Shag
Leucocarbo carunculatus carunculatus 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. Lynx Edicions BirdLife International.
Identification information: 76 cm. Large, black-and-white cormorant. Black head, hind neck, lower back, rump, uppertail-coverts, all with metallic blue sheen. White underparts. Pink feet. White patches on wings appear as bar when folded. Yellow-orange caruncles above base of bill. Similar spp. Pied cormorant P. varius has white face, neck, black feet, no white patches on wings. Voice Makes little noise at colonies, silent elsewhere.

Assessment Information [top]

Red List Category & Criteria: Vulnerable D1+2 ver 3.1
Year Published: 2015
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Gaze, P., Schuckard, R. & Weeber, B.
Facilitator/Compiler(s): Benstead, P., Mahood, S., McClellan, R., Pilgrim, J. & Taylor, J.
This species is classified as Vulnerable because it has a very small population and is restricted to four very small islands, rendering it susceptible to stochastic effects and human impacts. If human disturbance or set-netting were shown to cause a population decline or fluctuations in numbers or locations, it would require uplisting to Endangered.

Previously published Red List assessments:
2010 Vulnerable (VU)
2008 Vulnerable (VU)
2005 Vulnerable (VU)
2004 Vulnerable (VU)
2000 Vulnerable (VU)
1996 Vulnerable (VU)
1994 Vulnerable (VU)
1988 Threatened (T)

Geographic Range [top]

Range Description: Phalacrocorax carunculatus is endemic to New Zealand, where 92% of the population breeds on White Rocks, Sentinel Rock, Duffers Reef and Trio Islands, in the Marlborough Sounds, with two smaller colonies off D'Urville Island (Schuckard 1998, 2006). Birds formerly bred at D'Urville Peninsula and Te Kuru Kuru Island (Taylor 2000). Surveys between 1992 and 2002 indicate a population of c.645 birds, including 102-126 breeding pairs (Schuckard 1998, 2006). Numbers are believed to have remained stable over the last 50 years (historical counts are lower, probably because they were conducted at different times of day) (Schuckard 1994, 1998). The maximum feeding distance from the Duffers Reef colony is 24 km (Schuckard 1994).

Countries occurrence:
New Zealand
Estimated area of occupancy (AOO) - km2: 1
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 1
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Number of Locations: 4
Continuing 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: The population between 1992 and 2002 has been estimated at c.645 birds, including 102-126 breeding pairs, hence a population of 250-999 mature individuals is assigned here. This equates to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.

Trend Justification:  Numbers are believed to have remained stable over the last 50 years (Schuckard 1994, 1998, 2002).

Current Population Trend: Stable
Additional data:
Number of mature individuals: 250-999 Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
No. of subpopulations: 1 Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: Yes
No. of individuals in largest subpopulation: 100

Habitat and Ecology [top]

Habitat and Ecology: It breeds on small islets and rock stacks, with nests spaced c.1 m apart (Marchant and Higgins 1990). The main dietary item of at least part of the population - witch Arnoglossus scapha, a left-eyed flatfish - is not a species targeted by commercial and recreational fishers (Lalas and Brown 1998).

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): In the 1800s, collecting by ornithologists and hunting for the fashion trade may have affected numbers (Heather and Robertson 1997). Human disturbance (boats, aircraft and scuba divers) can cause desertion of nests and subsequent predation by gulls Larus spp. (Nelson 1971, Schuckard 1994). New interest from tour operators in the region may increase the problem. Set-nets are sometimes placed very close to colonies (Schuckard 1994) and present a major risk. Birds are occasionally illegally shot (Taylor 2000).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
All permanent colonies are wildlife sanctuaries, and are sign-posted. Charter boats have to remain 50-100 m from colonies, but it is thought that this may not be sufficient to avoid considerable disturbance (Schuckard 1994). Black rats Rattus rattus briefly colonised Duffers Reef but were eradicated by 1983 (Taylor 2000). In early 2012, a species conservation strategy, including a conservation management plan, was in the process of being produced for this species (R. Schuckard in litt. 2012).

Conservation Actions Proposed
Census all breeding colonies every five years using an established methodology (Taylor 2000). Obtain information on the extent of disturbance from vessels (P. Gaze in litt. 1999). Develop techniques for establishing colonies at new sites. Establish a code of conduct for commercial charter boat operators and fishers to minimise the disturbance of colonies. Obtain protection for all breeding grounds (Taylor 2000). Prevent marine farming close to colonies and feeding areas (B. Weeber in litt. 2000). Start an advocacy programme to encourage fishers to adopt set-net practices which minimise bycatch (Taylor 2000).

Citation: BirdLife International. 2015. Phalacrocorax carunculatus. The IUCN Red List of Threatened Species 2015: e.T22696846A85072933. . Downloaded on 01 December 2015.
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