Auckland Islands Research Articles

The white-capped albatross: a new breeding record for the Diego Ramírez Islands, Chile

Albatrosses are renowned for their high philopatry, which has been proposed as a major barrier to their dispersal and hybridization with other albatross species. Except for shy-type albatross species from New Zealand, examples of colonization of new breeding sites and interbreeding with closely related species are rare. During the austral summer of 2022, while conducting land-based monitoring of resident Black-browed (Thalassarche melanophris) and Grey-headed (T. chrysostoma) albatross populations on the Diego Ramírez Islands, Chile (56 S), we documented the first (and southernmost) breeding record of a nesting pair of White-capped Albatross (T. steadi), a species endemic to the Auckland Islands, New Zealand (~ 7000 km away). The species identity was confirmed through molecular analysis. This discovery underscores the importance of Diego Ramírez and its surrounding waters as a hotspot for global albatross conservation.

Xenotransplantation of solid organs

Transplantation of genetically modified porcine hearts and kidneys could become asolution to the persistent shortage of human organ donors. Progress has been made in genetic engineering of donor pigs, preservation techniques after organ harvesting and immunosuppression using co-stimulation blockade with anti-CD40/CD40L monoclonal antibodies. Progress has also been made in in the development of methods that detect pathogenic porcine viruses and prevent their transmission to the recipient. As normal land breed pig organs continue to grow in the recipient to their original size, different pig breeds (such as Auckland Island pigs) are now used which reach a final size suitable for humans. Alternatively, aknock-out of the growth hormone receptor gene has been established, e.g., in the 10GM genetically modified pigs from Revivicor/United Therapeutics, USA. The first clinical pilot studies including patients suffering from terminal heart failure are expected to start in Germany in about 2years.

Ancient mitogenomes reveal evidence for the Late Miocene dispersal of mergansers to the Southern Hemisphere

Abstract Mergansers are riverine and coastal piscivorous ducks that are widespread throughout North America and Eurasia but uncommon in the Southern Hemisphere. One species occurs in South America and at least two extinct species are known from New Zealand. It has been proposed that these Southern Hemisphere merganser lineages were founded by at least two independent dispersal events from the Northern Hemisphere. However, some morphological and behavioural evidence suggests that Southern Hemisphere mergansers may form a monophyletic clade that descended from only a single dispersal event from the Northern Hemisphere. For example, Southern Hemisphere mergansers share several characteristics that differ from Northern Hemisphere mergansers (e.g. non-migratory vs. migratory, sexual monochromatism vs. sexual dichromatism, long vs. short pair bonds). We sequenced complete mitogenomes from the Brazilian merganser and an extinct merganser from New Zealand—the Auckland Island merganser. Our results show that the Brazilian and Auckland Island mergansers are not sister-taxa, and probably descend from two separate colonization events from the Northern Hemisphere at least 7 Mya. Nuclear (palaeo)genomic data may help to further resolve the relationship between living and extinct mergansers, including merganser fossils from New Zealand that have not been subjected to palaeogenetic analysis.

Variable breeding success and its implication in the conservation of endangered yellow‐eyed penguin (Megadyptes antipodes) at the New Zealand subantarctic Auckland Islands

Abstract Knowledge of breeding success is essential for conservation, as it is required for monitoring populations and survival trends. Seabird reproductive success can be negatively affected by prey availability, marine‐based stochasticity, extreme weather events, individual breeders' performance and direct threats such as disease, predation and fisheries interactions. The endangered yellow‐eyed penguin (Megadyptes antipodes) is declining in mainland New Zealand, however, little is known about its breeding success in the subantarctic where the majority of the species breeds. Yellow‐eyed penguin breeding success data were collected from a total of 167 nests on subantarctic Enderby Island, Auckland Islands, New Zealand, from the 2015 to 2017 breeding seasons. This included egg and chick mortality and fledging rates, plus a wider sample of the fledgling condition of 276 chicks. Fledging success was higher than in mainland New Zealand in some years, although chicks were smaller and lighter on average, highlighting the need for more information on juvenile survival probabilities in the subantarctic. Breeding success measures were similar in 2015 and 2016, but a large egg mortality in 2017 caused a significant reduction in breeding success that year. Such variability requires more investigation into the correlates of breeding success, including possible stressors such as foraging success, adverse weather and environmental effects, and pathogens. These results demonstrate the need for ongoing monitoring of yellow‐eyed penguin breeding success across the subantarctic in order to establish baselines for normal variation and to determine whether anthropogenic (manageable) factors may be contributing to low productivity. This research highlights an important consideration for endangered species conservation; that breeding success may not be consistent over time, or across a species' entire range. Additional monitoring of all breeding populations should be carried out to ensure up‐to‐date information is available to inform conservation management decisions for the species.

Genetic diversity, growth and heart function of Auckland Island pigs, a potential source for organ xenotransplantation.

One of the prerequisites for successful organ xenotransplantation is a reasonable size match between the porcine organ and the recipient's organ to be replaced. Therefore, the selection of a suitable genetic background of source pigs is important. In this study, we investigated body and organ growth, cardiac function, and genetic diversity of a colony of Auckland Island pigs established at the Center for Innovative Medical Models (CiMM), LMU Munich. Male and female Auckland Island pig kidney cells (selected to be free of porcine endogenous retrovirus C) were imported from New Zealand, and founder animals were established by somatic cell nuclear transfer (SCNT). Morphologically, Auckland Island pigs have smaller body stature compared to many domestic pig breeds, rendering their organ dimensions well-suited for human transplantation. Furthermore, echocardiography assessments of Auckland Island pig hearts indicated normal structure and functioning across various age groups throughout the study. Single nucleotide polymorphism (SNP) analysis revealed higher runs of homozygosity (ROH) in Auckland Island pigs compared to other domestic pig breeds and demonstrated that the entire locus coding the swine leukocyte antigens (SLAs) was homozygous. Based on these findings, Auckland Island pigs represent a promising genetic background for organ xenotransplantation.

Mitochondrial DNA structuring of Antarctic prions (Pachyptila desolata, Procellariidae)

Prions (Pachyptila) are small seabirds with a Southern Hemisphere breeding distribution. Antarctic prion (Pachyptila desolata) and Salvin’s prion (P. salvini) are two species that are regularly recorded in New Zealand as beach-wrecks but they are difficult to distinguish morphologically. Salvin’s prion is restricted to breeding on the Prince Edward Islands and Crozet Islands in the Indian Ocean but Antarctic prions have a circumpolar breeding distribution on numerous sub-Antarctic and Antarctic islands in the Southern, South Atlantic and Indian Oceans. Our aim was to examine the level of mitochondrial DNA (mtDNA) structuring within Antarctic prion and Salvin’s prion colonies, to test whether this technique can determine the provenance of beach-cast birds. The Auckland Islands Antarctic prion population exhibited distinct mtDNA haplotypes from all other populations, supporting the suggestion that these islands may have been an ice-free refugium during the Last Glacial Maximum. All other sampled breeding populations shared haplotypes, limiting the use of these sequences for determining the provenance of beach-cast birds. None of our museum specimens of Salvin’s prion collected from breeding colonies produced DNA sequences. This result indicates that the method by which these specimens, which were collected in the 1960s and 70s, were preserved, or subsequent treatments, has resulted in the loss of their DNA.

Determination of the Copy Number of Porcine Endogenous Retroviruses (PERV) in Auckland Island Pigs Repeatedly Used for Clinical Xenotransplantation and Elimination of PERV-C.

Auckland Island pigs represent an inbred population of feral pigs isolated on the sub-Antarctic island for over 100 years. The animals have been maintained under pathogen-free conditions in New Zealand; they are well characterized virologically and have been used as donor sources in first clinical trials of porcine neonatal islet cell transplantation for the treatment of human diabetes patients. The animals do not carry any of the xenotransplantation-relevant viruses, and in the first clinical trials, no porcine viruses, including porcine endogenous retroviruses (PERVs) were transmitted to the human recipients. PERVs pose a special risk in xenotransplantation, since they are part of the pig genome. When the copy number of PERVs in these animals was analyzed using droplet digital PCR and primers binding to a conserved region of the polymerase gene (PERVpol), a copy number typical for Western pigs was found. This confirms previous phylogenetic analyses of microsatellites as well as mitochondrial analyses showing a closer relationship to European pigs than to Chinese pigs. When kidney cells from very young piglets were analyzed, only around 20 PERVpol copies were detected. Using these cells as donors in somatic cell nuclear transfer (SCNT), animals were born showing PERVpol copy numbers between 35 and 56. These data indicate that Auckland Island pigs have a similar copy number in comparison with other Western pig breeds and that the copy number is higher in adult animals compared with cells from young piglets. Most importantly, PERV-C-free animals were selected and the absence of an additional eight porcine viruses was demonstrated.

A tale of two species: Pringlea antiscorbutica and Azorella polaris, sub-Antarctic scurvy remedies

Abstract Pringlea antiscorbutica (Brassicaceae) and Azorella polaris (syn. Stilbocarpa polaris, Apiaceae) are endemic sub-Antarctic flowering plants of significant ecological and historical importance. Pringlea antiscorbutica occurs on Îles Kerguelen and Crozet, Prince Edward, and the Heard and MacDonald Islands; A. polaris on Auckland, Campbell, and Macquarie Islands. We examine the use of these unrelated species of “wild cabbage,” as scurvy remedies and sustenance for eighteenth–nineteenth-century sailors. We trace their European discovery, taxonomic treatment, morphological representation, and cultural association through the historical record. Scurvy killed more sailors during the sixteenth-nineteenth centuries than armed conflict and shipwrecks combined. Both plants were essential to the survival of sailors and formed a nutritious, carbohydrate-rich staple of their diets, however, attitudes to these plants were strongly influenced by cultural background. Use of P. antiscorbutica as a scurvy remedy was promoted by Cook and Anderson, leading to a greater historical legacy than A. polaris, and a unique contemporary research focus on the plant’s nutritional value and cultivation potential. In contrast, contemporary studies of A. polaris have been directed primarily at the plant’s protection. Pringlea antiscorbutica and A. polaris are intrinsically linked to human associations with the sub-Antarctic islands, which further increases their cultural and conservation value.

A glacial chronology for sub-Antarctic Marion Island from MIS 2 and MIS 3

It is increasingly apparent that local and regional factors, including geographic location, topography and climatic variability, strongly influence the timing and extent of glaciations across the Southern Hemisphere. Glacial chronologies of sub-Antarctic islands can provide valuable insights into the nature of regional climatic variability and the localised response(s) of glacial systems during periods of climatic change. With new cosmogenic 36Cl exposure ages from Marion Island in the southern Indian Ocean, we provide the oldest dated terrestrial moraine sequences for the sub-Antarctic islands. Results confirm that a local Last Glacial Maximum was reached prior to ∼56 ka when ice retreated with localised stand still events at ∼43 ka and between ∼38 and 33 ka. Evidence of ice re-advances throughout MIS 2 are limited and particularly absent for the cooling periods at ∼32 and ∼21 ka, and retreat continued until ∼17 ka ago. Any MIS 1 readvances on the island would be confined to altitudes above 900 m a.s.l. but the Holocene exposure ages remains to be documented. We compare Marion Island's glacial chronology with other sub-Antarctic islands (e.g., the Kerguelen archipelago, Auckland and Campbell islands and South Georgia) and review the evidence for a Southern Hemisphere glacial maximum in late MIS 3 (∼41 ka). At a regional scale we recognize sea surface temperatures, sea ice extent and the latitudinal position of the Southern Westerly Wind belt as key controls on equilibrium-line altitudes and ice accumulation due to their influence on air temperature and precipitation regimes. At an island scale, geomorphological mapping shows that deglaciation of individual glacier lobes was a-synchronous due to local physiographical and topographical factors controlling the island's micro-climate. We suggest that variability in deglaciation chronologies at smaller scales (particularly at the sub-Antarctic Islands) are important to consider when untangling climatic drivers across the Southern Ocean.

The benthic-pelagic continuum: Age class and sex differences in the use of the vertical dimension by a rare pinniped.

Sea lions as a group, display strong site fidelity, and varying degrees of vulnerability to environmental change, disease and fisheries interactions. One of the rarest pinnipeds, the New Zealand sea lion (NZSL, Phocarctos hookeri) has a very restricted breeding range. At Campbell Island/Motu Ihupuku, one of the two primary breeding sites, at-sea foraging behaviour is unknown. We hypothesised that NZSL of various sex and age classes would utilise the water column differently due to differing physiological constraints and therefore have different accessibility to prey resources. We tested whether sea lion diving behaviour varied in relation to (i) age and sex class, (ii) time of day and (iii) water depth. We also hypothesised that the proportion of benthic/pelagic diving, and consequently risk of fisheries interaction, would vary in relation to age and sex. Satellite telemetry tags were deployed on 25 NZSL from a range of age/sex classes recording dive depth, duration and location. Adult females and juveniles used inshore, benthic habitats, while sub-adult males also utilised benthic habitats, they predominantly used pelagic habitat at greater distances from the island. Adult females and juveniles exhibited shorter dives than the same age/sex classes at the Auckland Islands, suggesting a lower dive effort for these age/sex classes at Campbell Island/Motu Ihupuku. Adult females dived more frequently than other age/sex classes, likely operating closer to their physiological limits; however, further data for this age class is needed. Sub-adult male use of pelagic prey may increase their exposure to mid-water trawls; however, further research detailing the degree of spatial overlap with fisheries is required. This study highlights the utility of spatially explicit dive data to predict vertical habitat use, niche separation of various age and sex classes of marine predators and attribute potential fisheries interaction risk in relation to predator habitat use.

Hidden diversity in high-latitude Southern Hemisphere environments: Reinstatement of the genus Rama and description of Vandenhoekia gen. nov. (Cladophoraceae, Ulvophyceae, Chlorophyta), two highly variable genera.

The continental coasts and remote islands in the high-latitude Southern Hemisphere, including the subantarctic region, are characterized by many endemic species, high abundance of taxa, and intermediate levels of biodiversity. The macroalgal flora of these locations has received relatively little attention. Filamentous green algae are prolific in the intertidal of southern islands, but the taxonomy, distribution, and evolutionary history of these taxa are yet to be fully explored, mostly due to the difficulty of access to some of these locations. In this study, we examined specimens of the order Cladophorales from various locations in the high-latitude Southern Hemisphere including the subantarctic (the Auckland Islands, Bounty Islands, Campbell Island, Macquarie Island, and Kerguelen Islands), as well as mainland New Zealand, the Chatham Islands, Chile, and Tasmania. The analyses of the rDNA sequences of the samples revealed the existence of two new clades in a phylogeny of the Cladophoraceae. One of these clades is described as the novel genus Vandenhoekia gen. nov., which contains three species that are branched or unbranched. The amended genus Rama is reinstated to accommodate the other clade, and contains four species, including the Northern Hemisphere "Cladophora rupestris." In Rama both branched and unbranched morphologies are found. It is remarkable that gross morphology is not a predictor for generic affiliations in these algae. This study illustrates that much can still be learned about diversity in the Cladophorales and highlights the importance of new collections, especially in novel locations.

Review of the genus Nesomalium Steel, 1964 (Coleoptera, Staphylinidae, Omaliinae), with description of two new species from Ewing and Chatham islands.

The New Zealand genus Nesomalium Steel, 1964 (Omaliini) with six species is reviewed and redescribed, and briefly compared with related genera. All species are redescribed and illustrated, including two new species: N. marrisi sp. n. from Chatham Island and N. lescheni sp. n. from Ewing Island (Auckland islands). Lectotypes are designated for Omalium insulare Kiesenwetter, 1877 and O. pacificum Kiesenwetter, 1877. The key to species is provided. Nesomalium insulare (Kiesenwetter, 1877) is recorded from Adams and Ewing islands for the first time.

The company-microstate: The Auckland Islands and corporate colonialism in global history, 1849-52

AbstractThe Auckland Islands, a subantarctic archipelago 465 kilometres south of New Zealand, were the setting for one of the stranger episodes in the global history of colonial expansion. From 1849–52, these remote, inhospitable islands were governed and settled by a chartered company. The project was driven by lofty ambitions to simultaneously create a flourishing settler colony and unlock vast new whaling grounds in the Southern Ocean; the reality was a commercial disaster plagued by bitter internal disputes and a speedy abandonment. Drawing on the methods of global microhistory, I argue that the colonization of the Auckland Islands was a pivotal moment in the integration of the Southern Ocean world into global processes of governance, mobility, and trade. This anomalous case contributes to recent scholarship on ‘company-states’ and the central role of such hybrid polities in processes of cross-regional interaction and globalization.

Osteological variation in the spectacled porpoise (Phocoena dioptrica)

Cranial and post-cranial variation is described for a large series of specimens of spectacled porpoise from Argentina and compared with that for specimens from other areas of the Southern Hemisphere. Condylobasal length in 54 adult skulls was 276-424. Tooth counts were 16-26 and 17-23 in the upper and lower jaws, respectively. Total number of vertebrae (n = 20) was 66-70. The rostrum may be relatively smaller in the Auckland Islands than in other regions.

Hilarini (Diptera: Empididae) from the Auckland Islands New Zealand, the Homoplastic Loss of the Male Silk-Producing Basitarsus in Two Insular Species, and Notes on the Empidoidea of the Subantarctic Islands

The New Zealand taxa of the superfamily Empidoidea (minus Dolichopodidae) are briefly summarized. Two species, Hilara ranui n. sp. and Hilarempis motumaka n. sp. (Diptera: Empididae: Empidinae), from the Auckland Islands of New Zealand, where they appear to be common, are described. Both species show a homoplastic loss or reversal of the swollen, silk-producing, fore basitarsi characteristic of males in their respective genera. The environmental conditions of the Subantartic islands and their selective pressure on empidoid taxa are discussed.

Population assessment of White-capped Albatrosses Thalassarche steadi in New Zealand

ABSTRACT White-capped Albatrosses Thalassarche steadi breed only on New Zealand’s sub-Antarctic islands, principally the Auckland Islands. The species is commonly caught as bycatch in global longline and trawl fisheries, and it has been estimated that 8 000 birds are killed each year. In December or January between 2006 and 2017 we undertook annual population censuses of the White-capped Albatrosses breeding at the Auckland Islands using aerial photography. Estimated annual counts for the three breeding sites were adjusted using estimates of the proportion of birds clearly not associated with an active nest (loafers), to estimate annual breeding pairs for each breeding season. The estimated mean number of annual breeding pairs in the Auckland Islands during this period was 89 846 with high inter-annual variability (range: 74 031–116 025). Over the 12 years of the study adjusted counts for all sites combined showed a negative linear trend but this relationship was not statistically significant. Similar analyses using TRIM classified the population as ‘stable’. Given the estimated number of annual breeding pairs and the high frequency of biennial breeding it is likely that fisheries bycatch, if it has been estimated accurately, is impacting this population. Continuation of annual monitoring is recommended to increase the precision of the estimated population trend and help determine if the high levels of bycatch across multiple fisheries are sustainable in the long term.

Whisker stable isotope analysis used for proactive management of recolonising New Zealand sea lion population

New Zealand sea lions Phocarctos hookeri have experienced a 46% decline in pup production in the last 25 yr, driven by female deaths in trawl fisheries around the Auckland Islands. The only colony for this species recorded away from the subantarctics and this fishing impact is on Stewart Island. Despite the Stewart Island colony only being 1% of the species, it is significant, as it is currently the only stable population and is located in an area away from most on-land human impacts, although not away from potential fisheries pressures. To ensure this colony’s persistence, more information is needed on these sea lions’ diet, foraging behaviour, and local fisheries interactions for management that promotes their protection. The present research investigates the long-term foraging behaviour, and infers the diet, of female New Zealand sea lions on Stewart Island using their known foraging behaviour and linking this to their proximal and full-length whisker stable isotope values. Previous foraging studies found that these animals have small foraging areas with consistent mesopelagic diving behaviours. These behaviours, linked with their whisker stable isotope values, show consistency in foraging behaviour and inferred diet across their entire adult life. Currently, there are no known commercial fisheries bycatch issues for sea lions around Stewart Island. However, precautionary measures ensuring fisheries pressure does not increase and management to safeguard that deepwater trawling and finfish aquaculture remain absent would be proactive steps that should be undertaken for the protection of this new colony and for this Endangered species as a whole.

The eradication of feral goats from Auckland Island

Feral goats (Capra aegagrus hircus) were eradicated from Auckland Island, a National Nature Reserve and World Heritage site, between 1989 and 1991. Goats had established on the main Auckland Island following several releases in the 19th century. The population, amongst the most southerly ever recorded, was restricted to the northernmost areas of the island, with environmental conditions appearing unfavourable for southward spread, and the population stable at c. 100 individuals during scientific studies in the 1970s and 1980s.

The next frontier: assessing the feasibility of eradicating mammalian pests from Auckland Island

Auckland Island, the fifth largest island in New Zealand, is the only island in New Zealand’s subantarctic region where introduced mammalian pests remain (pigs, Sus scrofa; mice, Mus musculus; cats, Felis catus). The island has unique biodiversity and is a key site for progressing New Zealand’s goal to be free of several introduced predators by 2050. Recent island eradication successes have rekindled interest in eradicating pests from Auckland Island, and for the first time considering all three pests in one project.

Population trends of house mice during tussock mast seeding on Auckland Island

House mice (Mus musculus) are an invasive species on Auckland Island in the New Zealand subantarctic and planning for their eradication is underway. Mast seeding events cause rodent populations to irrupt, though little is known about this phenomenon in snow tussock grass (Chionochloa spp.) systems on Southern Ocean islands. The aim of this study was to understand population fluctuations of mouse abundance on Auckland Island for the 2 years following a mast event, and with which tools to monitor abundance, to inform planning of bait application for eradication.