Great Barrier (Aotea) andLittle Barrier (Hauturu) are two islands in the Hauraki Gulf; approximately 80 km north-east of Auckland, North Island, New Zealand. Little Barrier Island is a Nature Reserve (protected since 1895) and the public requires a permit to visit. Great Barrier Island has a small resident community, high numbers of visitors, and has large forested areas classified as a Scenic Reserve. Both islands are an important part of the Hauraki Gulf Marine Park, which was established in 2000. Little Barrier Island has no alien invasive species following the removal of 151 feral cats Felis catus from 1977 to 1980 and of Pacific Rats or Kiore Rattus exulans in 2004, whereas Great Barrier Island has populations of Norway or Brown Rats R. norvegicus, Pacific Rats, feral cats and feral pigs
Looking towards Little Barrier Island from Great Barrier Island, showing the Forestry Scenic Reserve (Kauri Agathis australis forest) and steep slopes
Both islands are densely forested; although Great Barrier Island also has large areas of modified farmland and regenerating scrub. Great Barrier Island has an excellent system of raised boardwalks on Mount Hobson to protect the environment.
Both islands are home to a number of procellariiform seabird species including the ACAP-listed Black or Parkinson’s Petrel Procellaria parkinsoni (illustrated here), Cook’s Petrel Pterodroma cookii and Grey-faced Petrel P. macroptera gouldi. Great Barrier Island is the world’s main breeding area for the Vulnerable Black Petrel which breeds around the summit of Mt Hobson/Hirakimata.
The Black Petrel colony on Great Barrier Island's Mount Hobson has been monitored since the 1995/96 breeding season. In 2011/12 the annual survey of over 400 study burrows resulted in an estimate of 1300 breeding pairs. Little Barrier Island holds about 100 pairs. Between 1986 and 1990, 249 Black Petrel chicks were transferred from Great Barrier to Little Barrier Island. A Black Petrel Action Group was established in 2011.
Photographs by Biz Bell
At night, Black Petrels climb rocks and trees to depart from the colony to forage at sea where they feed on squid and fish and also follow fishing vessels. Black Petrels are recognised as the most at-risk seabird in New Zealand from commercial fishing.
Click here to access the ACAP Species Assessment for the Black Petrel.
Abraham, E.R., Berkenbusch, K.N. & Richard, Y. 2010. The capture of seabirds and marine mammals in New Zealand non-commercial fisheries. New Zealand Aquatic Environment and Biodiversity Report No. 64. 52 pp.
Bell, E.A., Sim, J.L. & Scofield, P. 2011. Population parameters and distribution of the black petrel (Procellaria parkinsoni) on Great Barrier Island (Aotea Island), 2007/08. DOC Marine Conservation Services Series No.8. Wellington: Department of Conservation. 37 pp.
Imber, M.J., McFadden, I., Bell, E.A. & Scofield, R.P. 2003. Post-fledging migration, age of first return and recruitment, and results of inter-colony translocation of black petrels (Procellaria parkinsoni). Notornis 50: 183-190.
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.
Richard, Y., Abraham, E.R. & Filippi, D. 2011. Assessment of the risk to seabird populations from New Zealand commercial fisheries. Final Research Report for Ministry of Fisheries projects IPA2009/19 and IPA2009/20. Unpublished report held by the Ministry of Fisheries, Wellington. 66 pp.
Thompson, D.R. 2010: Autopsy report for seabirds killed and returned from observed New Zealand fisheries: 1 October 2008 to 30 September 2009. DOC Marine Conservation Services Series No. 6. Wellington: Department of Conservation. 37 pp.
Elizabeth (Biz) Bell, Wildlife Management International Limited, New Zealand and John Cooper, ACAP Information Officer, 13 April 2013