Phalacrocorax ranfurlyi 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Suliformes Phalacrocoracidae

Scientific Name: Phalacrocorax ranfurlyi Ogilvie-Grant, 1901
Common Name(s):
English Bounty Shag, Bounty Island Shag
Leucocarbo ranfurlyi ssp. ranfurlyi (Ogilvie-Grant, 1901) — Turbott (1990)
Taxonomic Source(s): Turbott, E.G. 1990. Checklist of the Birds of New Zealand. Ornithological Society of New Zealand, Wellington.
Identification information: 71 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. Caruncles absent. Voice Male makes call during displays only.

Assessment Information [top]

Red List Category & Criteria: Vulnerable D1+2 ver 3.1
Year Published: 2017
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Booth, A., Hiscock, J., Kennedy, M., Moore, P., Roberts, A., Taylor, G.A., Tennyson, A. & Weeber, B.
Facilitator/Compiler(s): Benstead, P., Mahood, S., McClellan, R., Moreno, R., Pilgrim, J., Taylor, J.
This species is classified as Vulnerable because it has a very small population and breeding range, rendering it susceptible to stochastic events and human impacts. If population fluctuations are shown to be extreme, or if there is any population decline, it may warrant uplisting to Critically Endangered.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Phalacrocorax ranfurlyi is restricted to the Bounty Islands, New Zealand. In 1978, 569 pairs were observed on 11 islands (Robertson and van Tets 1982). In 1997, a repeat census was attempted, but proved very difficult because it was not possible to land on the islands. However, colonies were noted on 13 islands, and 120 nests and 368 birds were counted (A. M. Booth in litt 1998). The islands were surveyed again from land in 2005, when 618 individuals were counted (R. Hitchmough in litt. 2005). In 2011, 393 nests were reported (Amey 2012). However, all of these counts covered only parts of the Island group. Although it is not known whether differences in the estimates are due to differing survey methods, differences in peak breeding times between years or a true change in numbers, a comparison with other species surveyed at the same time suggests that they show genuine trends (Taylor 2000, R. Hitchmough in litt. 2005). Surveys in 2011 suggest that the overall population has remained stable since 2005 (J. Hiscock in litt. 2012). In February 2013, the first bird count including an entire circumnavigation of the Bounty Islands group was carried out. The mean count of Bounty Island shags on land was 1,386.5 ± 75.5 birds (SD, range 1311-1462) and 150 birds were also seen swimming or flying in the area. Previous counts of individual birds (not nest counts) were undertaken in November and recorded 366 birds in 1997, 428 birds in 1998, 633 birds in 2004 and 304 birds in 2008 (Robertson and van Tets 1982; De Roy and Amey 2004; Clark et al. 1998; Russ and Terauds 2008). The population is likely to fluctuate markedly as a result of the effects of weather conditions on feeding (A. J. D. Tennyson in litt. 1994). 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) - km2:1Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:2100
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:1Continuing 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 is estimated to number at least 620 individuals, roughly equating to 410 mature individuals (R. Hitchmough in litt. 2005).

Trend Justification:  Boat-based surveys conducted in 2011 suggest that numbers were similar to those counted in 2005 (J. Hiscock in litt. 2012), probably indicating that the population is stable overall.

Current Population Trend:Stable
Additional data:
Number of mature individuals:900Continuing decline of mature individuals:Unknown
Extreme fluctuations:NoPopulation severely fragmented:No
No. of subpopulations:1Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:Yes
No. of individuals in largest subpopulation:100

Habitat and Ecology [top]

Habitat and Ecology:It breeds mostly on narrow cliff-side ledges, with nests often as little as 1 m apart (Robertson and van Tets 1982, Heather and Robertson 1997). It feeds on fish, snails, squid, isopods and crabs (Robertson and van Tets 1982).

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): Extreme weather conditions may be a threat (A. J. D. Tennyson in litt. 1994). Nesting sites may be restricted by the presence of large numbers of fur seal Arctocephalus forsteri, Salvin's Albatross Thalassarche salvini and Erect-crested Penguin Eudyptes sclateri (Marchant and Higgins 1990). The introduction of mammalian predators is very unlikely, but remains a possibility. The most likely long-term threat to the species is posed by changes to the marine environment around the islands, possibly driven by climate change.

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
The Bounty Islands are nature reserves and are free of introduced predators. In 1998, they were declared part of a World Heritage Site.

Conservation Actions Proposed
Complete a full census of all colonies every 10 years, including a census of nest-sites and breeding pairs (A. D. Roberts in litt. 1999, Taylor 2000). Turn the World Heritage Site territorial sea (out to 12 nautical miles) into a marine reserve and restrict all fishing (B. Weeber in litt. 2000).

Amended [top]

Amended reason: Edited: Geographic Range. The estimated number of mature individuals and global population were altered. Added references and also added a new Compiler.

Citation: BirdLife International. 2017. Phalacrocorax ranfurlyi (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T22696876A112399604. . Downloaded on 25 May 2018.
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