email a friend
printable version
VU
Buller's Shearwater Ardenna bulleri

Justification
This species qualifies as Vulnerable because the population is restricted to a very small area when breeding, and remains at risk from the accidental introduction of predators and other catastrophes. If it succeeds in expanding its range, it may be downlisted to Near Threatened.

Taxonomic source(s)
Brooke, M. de L. 2004. Albatrosses and Petrels Across the World. Oxford University Press, Oxford.
Christidis, L.; Boles, W. E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
SACC. 2006. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.html#.
Turbott, E. G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.

Taxonomic note
Ardenna bulleri (del Hoyo and Collar 2014) was previously placed in the genus Puffinus.

Synonym(s)
Ardenna bulleri Christidis and Boles (2008), Puffinus bulleri Salvin, 1888

Identification
46 cm. Large, grey, black-and-white shearwater with broad wings, buoyant flight and wedge-shaped tail (normally folded). Blackish-brown head, neck. Grey wings, back with large dark "M" across wings. Grey uppertail with black tip. White underparts, underwing. Slim, grey bill with dark tip. Similar spp. Unlike any other Pacific shearwater. Juan Fernández Petrel Pterodroma externa has dark leading edge to underwing. Voice Generally quiet at sea. Assorted howlings, wailings at colony. Calls are very similar to those of Sooty Shearwater P. griseus (G. Taylor in litt. 2012).

Distribution and population
Puffinus bulleri breeds only at the Poor Knights Islands, New Zealand. The species is restricted to two main islands, Aorangi and Tawhiti Rahi, and five other islets and stacks (Marchant and Higgins 1990). In the 1980s, one pair was found breeding on the Simmonds Islands, in the far north of New Zealand (Taylor 2000). Between 1938 and 1981, the population on Aorangi increased from c.200 to c.200,000 pairs (Harper 1983, Heather and Robertson 1997). However, surveys in 2011 suggested that there were fewer than 200,000 burrows, and perhaps only c.50,000 (G. Taylor in litt. 2012). In 2011, breeding success on Aorangi Island was noted to be very low, with only 16 chicks found in the 150 burrows sampled (G. Taylor in litt. 2012). The total population has been estimated at 2.5 million birds (Marchant and Higgins 1990), although this now regarded as too high (G. Taylor in litt. 2012). It migrates to the northern Pacific Ocean, from Japan to North America and east to California, and is occasionally found off South America (Heather and Robertson 1997, Taylor 2000).

Population justification
The total population is estimated at 2.5 million birds (Marchant and Higgins 1990), although this is now likely to be too high (G. Taylor in litt. 2012).

Trend justification
Pigs were exterminated on Aorangi in 1936 and the population has increased since then, although it is now suspected to be stable or decreasing (G. Taylor in litt. 2012).

Ecology
It nests in burrows or on rock-crevices and ledges, often under dense vegetation. It feeds on krill, small fish, salps and jellyfish (Marchant and Higgins 1990, Heather and Robertson 1997).

Threats
It was previously caught in north Pacific drift-nets (Gould et al. 1998), and is still potentially at risk from set-nets. It may be caught on longlines, in trawling operations and on hand and reel lines, but little documented evidence is available (Taylor 2000). Domestic pigs were previously a threat (removed in 1936), and the species would be at risk of mammalian predators if introduced. 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 218 m (BirdLife International, unpublished data). Poor breeding success recorded on Aorangi Island in 2011 may have been related to a strong La Niña climate pattern in 2010-2011, but data from some birds fitted with geolocators indicated that incubation shifts were around twice the length of those published in the 1980s (G. Taylor in litt. 2012). There has been intensive purse-seine fishing of pelagic fish in the Hauraki Gulf in recent decades, which may have impacted the species through food resource depletion, as it is known to feed in these areas and, perhaps connected to this, populations of Red-billed Gulls Larus scopulinus on the Mokohinau Islands have crashed from c.20,000 birds in the 1960s to fewer than 500 birds in 2011 (G. Taylor in litt. 2011). Further investigation is required.


Conservation Actions Underway
The eradication of pigs from Aorangi in 1936 caused a massive increase in the population, with the recolonisation probably coming from the nearby predator-free island, Tawhiti Rahi (Heather and Robertson 1997). Fishing has been banned at the Poor Knights Islands Marine Reserve since 1996 and entry onto the island reserve is prohibited (Szabo in litt. 2004). The International Maritime Organisation (IMO) established the world's first mandatory "area to be avoided" (ATBA) for large shipping vessels, including oil tankers, around the islands in 2004 (Szabo in litt. 2004). Breeding islands have permanent poisoned bait stations and each island is checked every year for any evidence that rodents have arrived (G. Taylor in litt. 2012). The species has been the subject of tracking studies utilising geolocators, with further data collection planned for 2013 (G. Taylor in litt. 2012).
Conservation Actions Proposed
Complete an accurate population census (including on Aorangi Island, to better assess breeding numbers [G. Taylor in litt. 2012]), assess the current status of breeding on Simmonds Islands and identify any signs of prospecting on other island groups. Establish monitoring plots on Poor Knights to determine the rate and pattern of colony expansion (Taylor 2000). Quantify the impact of bycatch during fishing activities. If judged necessary, work with fisheries to develop bycatch reduction measures.

References
Gould, P.; Ostrom, P.; Walker, W. 1998. Foods of Buller's Shearwaters (Puffinus bulleri) associated with driftnet fisheries in the central North Pacific Ocean. Notornis 45: 81-93.

Harper, P. C. 1983. Biology of the Buller's Shearwater (Puffinus bulleri) at the Poor Knights Islands, New Zealand. Notornis 30: 299-318.

Heather, B. D.; Robertson, H. A. 1997. The field guide to the birds of New Zealand. Oxford University Press, Oxford, UK.

Marchant, S.; Higgins, P. J. 1990. Handbook of Australian, New Zealand and Antarctic birds, 1: ratites to ducks. Oxford University Press, Melbourne.

Taylor, G. A. 2000. Action plan for seabird conservation in New Zealand. Department of Conservation, Wellington.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Calvert, R., Mahood, S., McClellan, R., Taylor, J.

Contributors
Szabo, M., Taylor, G.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2014) Species factsheet: Ardenna bulleri. Downloaded from http://www.birdlife.org on 30/10/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 30/10/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Vulnerable
Family Procellariidae (Petrels, Shearwaters)
Species name author Salvin, 1888
Population size mature individuals
Population trend Stable
Distribution size (breeding/resident) 110,000,000 km2
Country endemic? Yes
Links to further information
- Additional Information on this species