Taxonomy

formally described

George Robert Gray George Robert Gray FRS (8 July 1808 – 6 May 1872) was an English zoologist and author, and head of the ornithological section of the British Museum, now the Natural History Museum, in London for forty-one years. He was the younger brother o ...

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

Sydney Parkinson Sydney Parkinson (c. 1745 – 26 January 1771) was a Scottish botanical illustrator and natural history artist. He was the first European artist to visit Australia, New Zealand and Tahiti. Parkinson was the first Quaker to visit New Zealand. ...

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

Distribution

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

It is often seen in the outer

Hauraki Gulf The Hauraki Gulf / Tīkapa Moana is a coastal feature of the North Island of New Zealand. It has an area of 4000 km2, There is also a small colony present on Little Barrier Island of c. 250 birds. In addition to breeding birds, there are likely to be a further 6000 juveniles, pre-breeders and non-breeding birds at sea. Black petrels may range from the east coast of Australia all the way to the coast of South America between Mexico and Peru and the Galapagos islands. Females and males forage separately and in different places – it is not known why. Birds forage much closer to the Hauraki Gulf over the summer and autumn while incubating an egg and raising a chick – mainly in the Tasman Sea and to the north-east of New Zealand.

Behaviour

Breeding

Breeding takes place from October to June in the Hauraki Gulf. Adults return to the colony in mid-October to clean burrows, pair and mate with the same partner. Males will return to the same burrow every year and try to attract another female if their mate does not return or if there is a "divorce" (about 12% annually). Pairs then depart on "honeymoon", returning to the colony again in late November when the females lay a single egg. Both birds share incubation of the egg for 57 days (about 8 weeks). Eggs can hatch from late January through February. Chicks fledge after 107 days (15 weeks) from mid-April through to late June - about 75% of chicks survive to fledge. In 2011 breeding success fell to 61% for unknown reasons. Adults and chicks migrate to South America for winter (to waters off the Ecuador coast) – only 10% of fledged chicks survive this first year. Juveniles will remain at sea in the West Pacific for 3–4 years until they are ready to breed – survival rate is 46% during this time vs 90% for birds over 3 years old ). At about 4 years old, pre-breeding birds will fly back to the colony to find a mate – this may take 1-2 seasons.

Feeding

They may feed at night or during the day (unlike albatrosses which do not feed at night) Birds will aggressively follow fishing boats and long line hooks and may dive up to 20m below the surface after baits. Black petrels can cover amazing distances – the longest recorded foraging trip for a bird from Great Barrier Island is 39 days. Mapping of foraging patterns against fishing activity in New Zealand waters is currently underway.

Status and conservation

The black petrel is classified under DOC Threat Classification System as Nationally Vulnerable and by the International Union for Conservation of Nature or IUCN Red list: Vulnerable. Land-based population research at their breeding colonies since 1995 indicates the species is declining at a rate of at least 1.4% per year. At current survival rates, a fledged bird has a 1 in 20 chance of reaching breeding age (4+ years) and must breed 20 times successfully just to replace the current population.

Threats to survival

While at sea, black petrels are caught by commercial and recreational fishers both in New Zealand and overseas. Ministry of Fisheries research shows the black petrel is the most at-risk seabird in New Zealand from commercial fishing, estimating that between 725 and 1524 birds may have been killed each year in the period 2003 to 2009. Petrels may be drowned by taking long line hooks after they are set (launched) or when they are being pulled onto boats. Inshore Australasian snapper, snapper and

bluenose ''Bluenose'' was a fishing and racing gaff rig schooner built in 1921 in Lunenburg, Nova Scotia, Canada. A celebrated racing ship and fishing vessel, ''Bluenose'' under the command of Angus Walters, became a provincial icon for Nova Scotia and ...

bottom long-line fisheries are the greatest risks, especially where fisheries overlap with foraging patterns of breeding birds Reported deaths by fishers are low – since 1996, there have been only 38 birds reported caught and killed in New Zealand waters by local commercial fishers, mainly on domestic tuna long-line and on snapper fisheries. Less than 0.5% of boats in these high risk fisheries had observers on board in any one year. The level of deaths in fisheries outside New Zealand waters is unknown. There are anecdotal capture reports from recreational fishers especially in the outer Hauraki Gulf where birds are commonly reported. On Great Barrier Island feral pigs are known to dig up burrows and eat eggs and chicks – in one example in 1996 pigs destroyed 8 burrows in one incident. Feral cats can kill adults on the ground or at the nest as well as chicks. Cat numbers on Great Barrier Island are impacted by trapping by the Department of Conservation in the Whangapoua basin but there has been no specific protection of the colony to date.

Kiore The Polynesian rat, Pacific rat or little rat (''Rattus exulans''), known to the Māori as ''kiore'', is the third most widespread species of rat in the world behind the brown rat and black rat. The Polynesian rat originated in Southeast Asia, a ...

and ship rats are also present on Great Barrier Island but predation levels are between 1 and 6.5% per annum; kiore cannot eat through a black petrel egg. Risk to black petrel survival from a one-off event/events is significant due to limited habitat for breeding / i.e. a single site on Hirakimata on Great Barrier Island (for example fire, storm damage or predator invasion at main colony).

References

External links

BirdLife Species Factsheet
{{Taxonbar, from=Q276087 Procellaria Birds described in 1862 Taxa named by George Robert Gray Endemic birds of New Zealand