New Zealand storm petrel

Fregetta maoriana (Mathews, 1932)

New Zealand status: Endemic

Conservation status: Nationally Vulnerable

Geographical variation: Unknown. A larger form may be present around New Caledonia.

 
 
 
New Zealand storm petrel. Adult in flight. Outer Hauraki Gulf, January 2012. Image © Philip Griffin by Philip Griffin Philip Griffin © 2012

New Zealand storm petrel. Adult in flight. Outer Hauraki Gulf, January 2012. Image © Philip Griffin by Philip Griffin Philip Griffin © 2012

The New Zealand storm petrel is a fast-flying black-and-white storm petrel. A small bird, it has created quite a storm, flying in from extinction in January 2003 when one was sighted by a group of birdwatchers in waters off Whitianga (eastern Coromandel). Luckily, photographs were taken of the bird. Initially thought to be a black-bellied storm petrel, it was later correctly identified to be the New Zealand storm petrel, known only from three specimens collected in the nineteenth century (two in 1827 and one before 1895). Since its rediscovery in 2003, annual surveys have confirmed its presence within northern New Zealand waters, identifying a core region of activity during the New Zealand summer in and around the outer Hauraki Gulf. The first in-the-hand examination of a New Zealand storm petrel came on the night of 4 November 2005 when a bird flew onto a fisherman’s boat near Little Barrier Island. By coincidence this fisherman was an ex-conservation officer who recognised the bird as “something special”.

Subsequently a four-year capture program was undertaken 2005-2009, capturing a further 11 New Zealand storm petrels. Genetic analysis of these birds confirmed them as being the same as the original museum specimens. Tantalising evidence for the local breeding of the New Zealand storm petrel was acquired in January 2011 with a ‘freakish’ observation of a plant stalk attached to a New Zealand storm petrel’s leg. This observation strongly indicated the bird had been ashore for breeding and identification of the stalk to a plant found naturally only in northern New Zealand supported local breeding. In 2012 an intensive at-sea capture program succeeded in capturing 20 New Zealand storm petrels at sea, from early February to late May. Tellingly most showed signs of breeding with bare “brood patches” on their bellies (used to incubate eggs). Moreover, by catching birds across a four month window regrowth of feathers over the brood patches of birds has been observed, and the timing for the stages of breeding, i.e. incubation and chick rearing, could be determined. This was confirmed in February 2013, when birds were successfully tracked to breeding burrows in the forested interior of Little Barrier Island, and the first nests and chicks of the New Zealand storm petrel were found.

Identification

The New Zealand storm petrel is a small storm-petrel, mostly dark blackish-brown on the head, breast and upperparts, with a sharply defined white rump. The white belly and vent have highly variable dark streaking along the flanks and extending across the belly, the streaks are more scattered and less distinct in the central belly area. There is an indistinct, paler wing bar on inner upperwing. Mostly-white coverts create a white central panel on the underwing, with a broad dark leading edge. The bill, legs and feet are all black; the feet extend beyond the tail in flight. In most wind conditions, flight is direct, with swallow-like rapid changes in direction. Birds also stall and stop over sea surface, lowering feet to momentarily dabble.

Similar species: Wilson’s storm petrel is similar in size, however it lacks the white underparts including the white underwing panel, making the two species fairly easy to separate in the field. Also, when seen feeding together, wings of Wilson’s storm petrel are more rounded and flight behaviour more ‘fluttery’ and butterfly-like. Black-bellied storm petrel is larger (53 g cf 35 g) and has different, bulkier proportions; its feet extend beyond the tail, but not as much as with New Zealand storm petrel. The dark markings on the central belly of black-bellied storm petrels typically create a solid dark line, cf. streaking in New Zealand storm petrel. White-bellied storm petrels from the South-west Pacific region are larger with different, bulkier proportions; their feet do not extend beyond the tail, and they have a shortened, almost cut-off appearance. Dark polymorphic forms (breeding on Lord Howe Island) could be confused with New Zealand storm petrel if not seen well, particularly heavily streaked birds of the latter. White-bellied Storm-petrels can exhibit streaking along the flanks; however the more robust-size and lack of foot extension should separate these two. Grey-backed storm petrel lacks the sharp white rump, and has relatively short, rounded wings. However, in some lights, its clean white underparts, including central panel to underwing, could induce confusion with New Zealand storm petrel. ‘New Caledonian storm petrel’ (as yet undescribed) has been observed off Noumea Lagoon and the east coast of Australia; while similar to New Zealand storm petrel, it is larger in size (it has been seen alongside three other storm petrel species for size comparison).

Distribution and habitat

New Zealand storm petrels breed under tall forest in the interior on Little Barrier Island. At sea, they are known predominantly from sightings and captures from northern New Zealand waters. Sightings of birds in moult off Australia (Queensland, New South Wales and Victoria) suggest post-breeding movement across the Tasman and north to the Coral Sea. Sightings off New Caledonia may prove to be a similar or related, larger taxon. 

Population      

No accurate data. The low rate of resightings of banded birds (two up to 2013) suggests a population of hundreds if not thousands of birds.

Threats and conservation

Little Barrier Island/Hauturu is free of introduced mammal predators following the eradication of feral cats in 1980 and Pacific rats in 2004. It is remarkable that the storm petrels persisted (undetected) in the presence of cats and rats. The birds should thrive as long as the island is maintained pest-free. The conservation status of this species was changed from data deficient to nationally endangered in 2013.

Breeding         

The first New Zealand storm petrel nests were discovered in February 2013 by radio-tracking birds caught at sea. The burrows found to date (May 2013) are crevice-like in crumbly, rocky, litter-covered ground under forest, and contained downy chicks expected to fledge in late May or June.

Behaviour and ecology

New Zealand storm petrels are generally solitary at sea. On calm days they can be observed sitting with other seabirds (e.g. fairy prion, Buller’s shearwater, Cook’s petrel). Groups of 10-20 birds can gather if attracted to chum.

Food

Regurgitations from captured New Zealand storm petrels, while few, have included crustaceans. They feed by dipping and surface-seizing, and on occasion by shallow-plunging. 

Websites

http://en.wikipedia.org/wiki/New_Zealand_Storm_Petrel

http://www.birdlife.org/datazone/speciesfactsheet.php?id=30105

References

Flood, B. 2003. The New Zealand storm-petrel is not extinct. Birding World 16: 479-483.

Gaskin, C.P.; Baird, K.A. 2005. Observations of black and white storm petrels in the Hauraki Gulf, November 2003 to June 2005. Were they of New Zealand storm-petrels? Notornis 52: 181-194.

Gaskin, C.P.; Fitzgerald, N.; Cameron, E.; Heiss-Dunlop, S. 2011. Does the New Zealand storm-petrel (Pealeornis maoriana) breed in northern New Zealand? Notornis 58: 104-112

Miskelly, C.M.; Dowding, J.E.; Elliott, G.P.; Hitchmough, R.A.; Powlesland, R.G.; Robertson, H.A.; Sagar, P.M.; Scofield, R.P.; Taylor, G.A. 2008. Conservation status of New Zealand birds, 2008. Notornis 55: 117-135.

Rayner, M.J.; Gaskin, C.P.; Stephenson, B.M.; Fitzgerald, N.B.; Landers, T.J.; Robertson, B.C.; Scofield, P.R.; Ismar, S.M.H.; Imber, M.J. 2013. Brood patch and sex ratio observations indicate breeding provenance and timing in New Zealand storm petrel (Fregetta maoriana). Marine Ornithology 41: 107-111.

Robertson, B.C.; Stephenson, B.M.; Goldstein, S.J. 2011. When discovery is not enough: taxonomic uncertainty hinders conservation of a critically endangered bird. Molecular Phylogenetics and Evolution 63: 949-952.

Robertson, H.A; Baird, K.; Dowding, J.E.; Elliott, G.P.; Hitchmough, R.A.; Miskelly, C.M.; McArthur, N.; O’Donnell, C.F.J.; Sagar, P.M.; Scofield, R.P.; Taylor, G.A. 2017. Conservation status of New Zealand birds, 2016. New Zealand Threat Classification Series 19. Wellington, Department of Conservation. 27p.

Saville, S.; Stephenson, B.; Southey, I. 2003. A possible sighting of an ‘extinct’ bird – the New Zealand Storm-Petrel. Birding World 16: 173-175.

Stephenson, B.M.; Gaskin, C.P.; Griffiths, R.; Jamieson, H.; Baird, K.A.; Palma, R.L.; Imber, M.J. 2008. The New Zealand storm petrel (Pealeornis maoriana Mathews, 1932): first live capture and species assessment of an enigmatic seabird. Notornis 55: 191-206.

Recommended citation

Gaskin, C.P. 2013 [updated 2017]. New Zealand storm petrel. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz

New Zealand storm petrel

Breeding season
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Egg laying dates
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