The Auckland Islands are the largest island group in the New Zealand subantarctic region, and have the most diverse avifauna, including eight endemic taxa. We present the first comprehensive review of the avifauna of the Auckland Islands, based on a database of 23,028 unique bird records made between 1807 and 2019. At least 45 species breed (or bred) on the islands, with a further 77 species recorded as visiting the group as migrants, vagrants, or failed colonisers. Information on the occurrence of each species on the different islands in the group is presented, along with population estimates, a summary of breeding chronology and other reproductive parameters, and diet where known. The frequency at which 33 bird species were encountered during visits to the seven largest islands is compared graphically to facilitate comparison of each island’s bird fauna in relation to habitat differences and the history of introduced mammals. Disappointment Island (284 ha) is the least modified island in the group. However, it lacks forest, and so has a very restricted land bird fauna, lacking ten species that breed on other islands in the group. Auckland Island (45,889 ha) is the only major island in the group where introduced mammals are still present. As a result, it also has a depauperate bird fauna, with at least 11 species completely absent and a further seven species reported at lower frequencies than on the next largest islands (Adams and Enderby Islands).
Banded dotterels (tūturiwhatu, Charadrius bicinctus bicinctus) are small plovers inhabiting New Zealand’s braided rivers, estuaries, seashores, and open country. They are considered Nationally Vulnerable under national threat listing criteria, but with uncertainty around the trend estimation. We collated and reviewed counts of banded dotterels on their braided river breeding grounds from throughout the country, 1962–2017, to describe their distribution, assess population trends, estimate rates of population change, and assess the appropriateness of the threat status given to this species. We also used nationwide winter count data for banded dotterels from 1984 to 2018 as an independent measure to compare trends. Banded dotterel counts were recorded for 119 braided and shingle river reaches, mostly in the South Island (87%) with far fewer rivers in the North Island (13%). The sum of banded dotterel counts was 12,730 birds when tallying the most recent counts/river. Although they were most widespread in the South Island, particularly Canterbury, the majority (>50%) of dotterels counted on the most recent surveys were from just 10 (8%) rivers with the largest single concentrations on three Hawkes Bay rivers. Counts suitable for long-term trend analysis were only available for South Island sites. Widespread declines in banded dotterel count indices were recorded. The weighted mean annual rate of change across 33 South Island rivers was -3.7% p.a. (per annum), which equates to a 52.3% decline over 20 years (~3 generations). We also detected a negative trend in dotterel numbers based on national winter count data, but of a smaller magnitude (-1.4% p.a., equating to a 25% decline over 20 years). However, trends in Australia, where c. 60% of banded dotterels over-winter, are unknown. In contrast, a significant population increase was measured on the Hakatere Reach of the South Ashburton River, which has intensive, sustained predator control, and several predator trapping initiatives on other braided rivers and coastal areas indicate declines can be reversed with management if applied at an extensive landscape scale. Banded dotterels are subject to a wide range of threats including very high levels of predation by invasive predators, human disturbance on breeding grounds, and habitat loss and degradation. Using the precautionary principle, the rates of decline on South Island braided rivers confirm the classification of Nationally Vulnerable using the NZ Threat Classification system. However, results suggest that the IUCN threat status for banded dotterel should be reclassified from Least Concern to Endangered.
For 11 breeding seasons, a colony of little penguins (Eudyptula minor) was monitored at South Bay, Kaikōura. The 106 breeding attempts from 86 pairings consisted of 68 single clutches, eight attempts made up four replacement clutches (an unsuccessful original clutch followed by a second clutch by a pair in one season), 26 attempts consisting of 13 double broods (a successful original clutch followed by a second clutch by a pair in one season), and one complex triple brood (three successful attempts by a penguin in one season, the triple brood, plus another successful attempt by its first mate after separation). The earliest laying date was 18 April for multiple brooders and 12 August for single clutch pairs. Single clutch pairs raised a mean of 1.42 fledglings/clutch. Four pairs with first clutch failures laid replacement clutches; one was successful. Seven of the 13 pairs of double brooders successfully raised the second clutch; the productivity of the 13 pairs was 2.69 fledglings/pair. The first record of a successful triple brood by little penguins was complex in that the female separated from her mate after the first brood chicks fledged, and then completed her second and third broods with a different male. Her original mate also produced a further brood with another female to complete his double brood. These four clutches laid eight eggs of which seven hatched and six chicks fledged. This may also be the first reported multiple brood with a change of mate after a successful first brood. On a colony-wide basis productivity per season was 2.36 eggs/pair, 1.80 chicks/pair, and 1.66 fledglings/pair. Previous research indicated Kaikōura birds belonged to the New Zealand Only (NZO) clade of little penguins. As double brooding and rafting are traits of the Australia and south east New Zealand (ASENZ) clade only, this classification is now questionable suggesting a mix of both clades and/or hybrids.
Population sizes of light-mantled sooty albatross (Phoebetria palpebrata, LMSA) at the three New Zealand breeding sites (Auckland, Antipodes, and Campbell Islands) are poorly known. Annual counts since 1999 of a small number of LMSA nests show a long-term population decline on Adams Island, Auckland Islands. Mean nest numbers in 2016-17 were 10% down on counts in 1999–2000, with an annual rate of decrease, lambda, of 0.44 in the period 1999–2019. Three methods to estimate the breeding population size were trialled: ground counts of nests (Adams); aerial photography of LMSA with ground-truthing (Adams); and boat-based counts of LMSA on coastal cliffs (Campbell). Ground counts in a clearly delimited area were repeatable (42 and 40 active nests in 2017 and 2018, respectively), thus useful for monitoring, but ground counts are too limited for a whole-island population estimate. Aerial photography overestimated the number of active nests by 12.5% compared with ground counts. Ground-truthing showed that most apparently occupied nests contained an egg, and so nests occupied by birds with no egg are a smaller error source when interpreting aerial photographs than for other albatrosses. Boat-based LMSA counts proved inaccurate due to vessel movement. Considering that the terrain favoured by LMSA is very difficult to access, population size estimates based on aerial photography with ground calibration for apparent breeders appear the most effective of the techniques trialled. Ongoing counts at vantage-point and ground-count sites enable continued monitoring of LMSA trends at Adams Island.
Twenty-four breeding colonies of three petrel species were found on 18 of 26 islands surveyed in Breaksea Sound/Te Puaitaha, Fiordland National Park, New Zealand, in November 2017 and December 2019. All vegetated islands within Breaksea Sound were surveyed, along with 20 islands in Dusky Sound/Tamatea that were not included in an initial survey in November 2016 (eight of these additional Dusky Sound islands had breeding petrels, including three with broad-billed prions Pachyptila vittata). Sooty shearwater (Ardenna grisea) was the most widespread and abundant species in Breaksea Sound, with an estimated 6,950 burrows on 14 islands, while broad-billed prions were breeding on seven islands (2,100 burrows estimated). We record the first evidence of mottled petrels (Pterodroma inexpectata) breeding in Breaksea Sound, which is now their northernmost breeding location. Burrow occupancy rates were not assessed for any of the species. Most of the islands in Breaksea Sound had previously been surveyed during 1974 to 1986, before Norway rats (Rattus norvegicus) were eradicated from Hāwea and Breaksea Islands, and stoats (Mustela erminea) controlled to near zero density on Resolution Island and adjacent islands (including the inner Gilbert Islands and Entry Island). Following pest mammal control or eradication, broad-billed prions have colonised at least four additional sites. Sooty shearwaters were found at five sites in Breaksea Sound where they had not been recorded in 1980–83, and at one site they had increased by more than 50-fold since rat eradication. When combined with data from the 2016 and 2017 surveys, more than 75,700 petrel burrows are estimated to be present in southern Fiordland.
The Auckland Islands comprise the largest and most researched island group in the New Zealand subantarctic region, and have the largest number of endemic bird taxa. Paradoxically, they are the only one of the five island groups that has not yet been the subject of a comprehensive avifaunal review. We summarise the history of ornithological exploration of the group, and where this information is held, based on a database of 23,028 bird records made between 1807 and 2019. More than 76% of these observations were unpublished, with the two largest sources of information being Heritage Expedition wildlife logs (5,961 records) and records collected during the Second World War coastwatching ‘Cape Expedition’ (4,889 records). The earliest records of endemic taxa are summarised, along with the earliest records of significant seabird breeding colonies. Citizen science (principally eBird, with 1,597 unique records) is a rapidly growing source of information, and new records of vagrant species continue to accumulate at a rapid rate. Compared with other subantarctic islands, Auckland Islands’ birds have received very little research attention, with most effort to date focused on a few large surface-nesting seabird species.
Disequilibrium of bird communities, due to introduced pests and human-caused habitat changes, is a fundamental property to be understood in restoration of island biota. In this paper, we suggest that the reestablishment of native forests and food webs favour long-established and native species, and is less favourable to more recently introduced species. To test this hypothesis, we compared population trends of native and non-native birds on five islands in the Ipipiri Group in the north of New Zealand. We used over 900 station counts starting in 2008 when habitat recovery and pest (rat [Rattus], mouse [Mus musculus], and stoat [Mustela erminea]) removal began, as well as comparing to a set of earlier counts. In general, we found that detection rates of most long-established endemic native species significantly increased, while non-native species mostly decreased, suggesting population increases and decreases, respectively. Of the native species, six are relatively recent natural immigrants to New Zealand, and most of these declined or remained unchanged. We suggest that the increase in long-established natives is likely due to increased size and quality of native bush areas making habitat more favourable to these natives, as well as reduced predation and competition from the pest mammals.
During southward migration from Alaska in 2006, a satellite-tracked female bar-tailed godwit (Limosa lapponica baueri) encountered adverse weather and stayed between 19 September and about 28 September 2006 at Ouvéa (Loyalty Islands, New Caledonia), where she apparently died. Ouvéa was visited between 27 September and 7 October 2007 to look for godwits. A total of eight godwits was recorded of which one, thought to be an adult female, may have been a dropout migrant. The remaining birds appeared to be immatures.
Maungatautari is a 3,240 ha pest-fenced ecosanctuary free of virtually all mammalian predators in Waikato, New Zealand. We used triennial 5-minute counts within the ecosanctuary and biennial surveys of residents up to 20 km from the perimeter pest fence to measure spillover of tūī from Maungatautari into the surrounding area over a 9-year period (2006–2014) following pest eradication. Following pest eradication in the ecosanctuary, tūī relative abundance increased there and in the surrounding largely unmanaged area. The mean number of tūī per 5-minute count within the ecosanctuary was 2.23 (se = 0.163) in 2005 and increased following predator eradication in 2006 to 3.33 (se = 0.206) in 2008, 3.76 (se = 0.193) in 2011, and 2.68 (se = 0.279) in 2014. The mean maximum number of tūī at one time observed by residents in the largely unmanaged area increased from 4.4 (max = 47, n = 320) in 2006 to 15.6 (max = 300, n = 138) in 2014. Tūī numbers in both the ecosanctuary and the surrounding area were positively correlated with time since pest eradication. In the largely unmanaged area surrounding Maungatautari, tūī numbers were also positively correlated with provision of artificial food, and negatively correlated with distance from the ecosanctuary. Wind was negatively correlated with the number of tūī recorded in 5-minute counts at Maungatautari. Our findings show that pest-free ecosanctuaries can facilitate increased abundance of volant birds in surrounding landscapes if habitat is available.
We report Records Appraisal Committee (RAC) decisions regarding Unusual Bird Reports received between 1 January 2017 and 31 December 2018. Among the 160 submissions accepted by the RAC were the first New Zealand records of Macquarie Island shag (Leucocarbo purpurascens) and Cox’s sandpiper (Calidris x paramelanotus), and the first accepted at-sea sightings of blue petrel (Halobaena caerulea), Salvin’s prion (Pachyptila salvini), Antarctic prion (P. desolata), and thin-billed prion (P. belcheri) from New Zealand coastal waters. We also report the second accepted breeding record (and first successful breeding) for glossy ibis (Plegadis falcinellus), and the second accepted records of red-footed booby (Sula sula) and laughing gull (Leucophaeus atricilla). Other notable records included the first record of nankeen kestrel (Falco cenchroides) from Campbell Island, and at least 5 northern shovelers (Anas clypeata) simultaneously present in June 2018.