|Scientific Name:||Pterodroma cervicalis (Salvin, 1891)|
|Taxonomic Source(s):||Turbott, E.G. 1990. Checklist of the Birds of New Zealand. Ornithological Society of New Zealand, Wellington.|
|Identification information:||43 cm. Large, grey-and-white petrel with distinctive white hindneck. Black cap extends to below eyes. White band extends from throat around hindneck. Grey upperparts, upperwing, with black "M" across wings. May have grey half-collar across upper breast. White underparts. White underwing with narrow, black trailing edge, black tip, wider black leading edge distal to carpal joint, short, bolder black bar extending towards centre of wing from joint. Similar spp. Distinguished from Juan Fernandez Petrel P. externa by stronger cap contrast, bolder black marking at leading edge of underwing distal to carpal joint. P. externa has grey nape, but some individuals become almost as white-necked as P. cervicalis.|
|Red List Category & Criteria:||Vulnerable D2 ver 3.1|
|Reviewer(s):||Butchart, S. & Symes, A.|
|Contributor(s):||Carlile, N., Garnett, S., Gaskin, C., MacAllan, I., Taylor, G.A. & Tennyson, A.|
|Facilitator/Compiler(s):||Anderson, O., Benstead, P., Calvert, R., McClellan, R., Taylor, J., Temple, H., Moreno, R.|
This species qualifies as Vulnerable because it has a very small range, on two or three very small islands, and it is therefore susceptible to stochastic events and human impacts.
|Previously published Red List assessments:|
|Range Description:||Pterodroma cervicalis breeds on Macauley Island in the Kermadec Islands, New Zealand (c.50,000 pairs in 1988), with a second small colony recently established on Phillip Island, off Norfolk Island (to Australia) with nests increasing from six in 1994 to 20 in 2005 (Priddel et al. 2010). It bred on Raoul Island, also in the Kermadec Islands, early in the 20th century (Taylor 2000). Two birds were found on Raoul Island in 2005 and 2006 covered in seed-burrs, possibly prospecting (Gaskin 2011). It migrates to the tropical and sub-tropical north Pacific Ocean (Spear et al. 1992) with recent sightings in Hawaiian waters (eBird) .|
The rare sub-species occulta breeds in small numbers on Vanua Lava, Vanuatu (Totterman 2009). In February 2010, it was photographed, 60 miles from the site of the original specimens, and only the second documented sighting since 1927; a total of 21 individuals was sighted over a three-day period, nine seen rafting before dusk (P. Harrison in litt. 2010). T
Native:American Samoa; Australia; Cook Islands; Fiji; French Polynesia; Guam; Japan; Mexico; Micronesia, Federated States of ; New Caledonia; New Zealand; Niue; Norfolk Island; Northern Mariana Islands; United States; United States Minor Outlying Islands; Vanuatu; Wallis and Futuna
Present - origin uncertain:French Southern Territories; Kiribati; Marshall Islands; Nauru; Papua New Guinea; Samoa; Solomon Islands; Tokelau; Tonga; Tuvalu
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The total population has been estimated at c.100,000 mature individuals (1988), roughly equivalent to 150,000 total individuals.|
Trend Justification: The population is thought to be increasing (Brooke 2004).
|Current Population Trend:||Unknown|
|Habitat and Ecology:||On Macauley Island White-necked Petrels nest in localised colonies, especially in Sandy Bay, on the slopes above Quadrat Gully, on the gully slopes and floor of Access Gully, on the plateau near Grand Canyon, in Jim’s Gully, and on the upper slopes of Mt Haszard. Although their burrows were once found on forested ridges on Raoul Island, all colonies on Macauley Island are under grass, sedges or fern (G. Taylor, pers. comm. in Gaskin 2011).. On Raoul, it nested below 300 m on high-altitude ridges (Marchant and Higgins 1990). Two birds were found on the northern terraces of the island (2005 and 2006) covered in the spiny burrs of a native grass (Cenchrus calyculatus) that prevented them from flying. These two birds were presumed prospecting birds; however, a return to breeding on this rugged island cannot be discounted. This species is also known (from at-sea observations) to be in the waters around Raoul Island in May (Gaskin 2011). |
On Phillip Island, it is a summer breeder, birds coming ashore as early as 11 November, but laying in January (Priddel et al. 2010), differing from the Macauley population by nesting among boulders and in crevices in rocky habitat with sparse understorey, below a canopy of mature white oaks Lagunaria patersonia that provide concealment from avian predators (Priddel et al. 2010). It has also been known to nest in artificial cavities. On Phillip Island, the only known nests are at the top of Long Valley, but other areas have potential nest sites (Priddel et al. 2010). It feeds mainly on squid (Heather and Robertson 1997). Little is known of the breeding biology.
|Continuing decline in area, extent and/or quality of habitat:||Unknown|
|Generation Length (years):||15.6|
|Movement patterns:||Full Migrant|
|Congregatory:||Congregatory (and dispersive)|
The population on Raoul was probably destroyed by feral cats and brown rat Rattus norvegicus (Taylor 2000). The Polynesian rat R. exulans was formerly present on Macauley (eradicated in 2006), but does not apparently attack eggs or chicks (Marchant and Higgins 1990). Feral goats were present on both Raoul and Macauley and trampled burrows. Rabbits were formerly present on Phillip Island, and extensive grazing and burrowing caused large-scale erosion (Taylor 2000). It remains vulnerable to the introduction of further mammalian predators, and also to fire and disturbance by visitors (Marchant and Higgins 1990). The most recent visits to Macauley Island indicate that a dense successional stage of fern-dominated vegetation appears to be displacing the species from some colonies; however, population level impacts are not currently known (G. Taylor in litt. 2012). 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 238 m (BirdLife International unpublished data).
Conservation Actions Underway
Goats were removed from Raoul and Macauley in 1984 and 1970, respectively. The eradication of rabbits from Phillip Island in 1985 may have resulted in the species colonising the island in the following years. Polynesian rats were eradicated from Macauley in 2006 and cats and rats were eradicated from Raoul Island between 2002 and 2006 (G. Taylor in litt. 2012). Two birds found on Raoul Island covered in seed burrs in 2005 and 2006 were presumed prospecting birds. Since 2007, automated sound attraction units have been installed on Raoul Island in an attempt to lure the species, although there is no evidence so far that this has worked, although breeding on this rugged island cannot be discounted as searches in promising gully areas are non-existent (C. Gaskin in litt. 2016). A study area on Macauley was established in 1988 (G. Taylor in litt. 1999). The Kermadec Islands are nature reserves with access by permit only. Extensive searches were conducted for incubating birds of this species in the upper reaches of Long Valley, the main water catchment of Phillip Island (N. Carlile in litt. 2012).
Conservation Actions Proposed
Map populations on Macauley Island and complete a census. Monitor Macauley every five years to ensure that no establishment of predators has occurred. Monitor the recovery of vegetation on Macauley and any negative effects on the species. Recapture birds in study area to determine data on survival and longevity every five years (Taylor 2000). On Raoul monitoring of acoustic attraction sites where White-necked Petrel calls are broadcast; use playback and spotlights to check for birds flying over land (Northern Terraces) during summer months; ground searches of ridges and slopes at western end of island (towards Hutchison Bluff) (C. Gaskin in litt 2016).
Survey Vanua Lava and assess threats.
|Citation:||BirdLife International. 2016. Pterodroma cervicalis. The IUCN Red List of Threatened Species 2016: e.T22697957A93648994.Downloaded on 20 September 2018.|
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