Publications Archive

This paper describes North Island kokako (Callaeas wilsoni) recovery actions and outcomes since 2000 at 11 sites with relict populations, and at 12 other mainland and three offshore island sites to where they have been translocated. Populations are now secure on pest-free Te Hauturu-o-Toi / Little Barrier Island and Kapiti Island, and Tiritiri Matangi Island is a valuable advocacy site. Maungatautari is a large (3,300 ha) pest-fenced and pest-free site that has demonstrated rapid kōkako recovery. All other sites are unfenced and require ongoing control of key pests. The national total of kōkako pairs has increased from c. 458 in 2000 to c. 2,327 in 2023; however, latest counts indicate populations at seven sites have declined. Future kōkako recovery will be assisted most by improved, large-scale pest control tools for unfenced mainland sites, and by sustained effective pest control in large key relict populations (Pureora, Te Urewera, Rotoehu, Mapara, and Mokaihaha).

Abstract: Tree martins (Petrochelidon nigricans) are vagrants to New Zealand from Australia, with the first record in 1851. However, there is some doubt as to whether every tree martin historical record can be assigned to this species, with the now-established welcome swallow (Hirundo neoxena) a likely confusion species. Records of tree martins and other hirundines were examined against historical record criteria in order to establish an accurate picture of past tree martin vagrancy. Forty-eight relevant records (1851–1978) were collated and reviewed. It was considered that 16 records were probable or confirmed tree martins, 19 were possible tree martins, and just three were possible welcome swallows. The remaining ten records were classified as unidentifiable, with most of these lacking descriptions. Only four 19th century tree martin records should be verified. None of the many 1892–93 hirundine invasion records could be certainly assigned to any particular species. Considering the tree martin was more frequently recorded, it is perhaps surprising it is the less successful colonist of the two species.

Abstract: Procellariiform seabirds are vulnerable to numerous threats, including the growing issue of urban light pollution. Seabirds that are found grounded are often treated by avian/wildlife rehabilitation centres, but approximately 30% do not survive. Here, we necropsied 19 grounded Cook’s petrels (tītī, Pterodroma cookii) that did not survive and report the cause of death and injuries. We also investigate potential risk factors, including association with light pollution, seabird sex, age, and sensory features. We found that a 70% of Cook’s petrels had head trauma, internal bleeding, and/or wounds as the main causes of death (p > 0.05). These injuries are consistent with collisions, likely due to disorientation from light pollution. Most Cook’s petrels were not stressed or in poor body condition, suggesting Cook’s petrels are typically healthy before being affected by lights. In the sample of Cook’s petrels studied, mortality was significantly biased towards young and male seabirds. Despite this apparent sex difference in collision risk, there was no detectable sex difference in measured sensory features, e.g. males did not have significantly larger eyes than females. The potential sex bias in death suggests male seabirds could be more vulnerable to light pollution, which warrants further research. Further research is also required to determine whether individual differences in sensory features relate to grounding risk, as our study only included a subset of dead seabirds. We also recommend that all grounded seabirds are taken to rehabilitation centres rather than released immediately.

Abstract: The current Buller’s albatross taxa (Thalassarche bulleri bulleri [southern] and T. b. platei [northern]) engage in transpacific migrations from breeding sites on New Zealand offshore islands to non-breeding areas in the south-eastern Pacific Ocean. Both taxa are identifiable from a combination of plumage colour features in the head and bill that are easy to detect at short distance (<15 m). There is also breeding allopatry between the taxa, with the onset of breeding 2.5 months earlier in the ‘northern taxon’. In this study, close-range sightings and captures of lured Buller ́s albatross individuals off southern Perú were carried out during two pelagic trips in May–July 2021 onboard a small- scale longline fishery wooden boat (12 m long), during their normal operations when targeting sharks. We report on the presence of 41 Buller ́s albatross, of which 40 were recognized as ‘northern taxon’ and one as ‘southern taxon’. The great majority of the ‘northern taxon’ were adults (92.5%), with the remaining identified as sub-adults (7.5%). Birds were sighted between 126 and 223 km offshore west-south-west from the port of Ilo, Perú (17°38.64 ́S, 71°20.77 ́W). Birds sighted were preferentially in oceanic areas above the abyssal plain (68% of sightings), with a mean depth of 4,537 m, demonstrating that the ‘northern taxon’ is a truly oceanic species. No birds were observed by us over the continental shelf. Discrimination of ‘northern taxon’ from ‘southern taxon’ is possible from a combination of the plumage colour features in the head and bill. However, identification and comparison of photographs for both taxa taken at sea can be problematic, due to varying light conditions, unless the birds can be drawn close to the photographer using attractants, such as offal discards.

Abstract: We report Records Appraisal Committee (RAC) decisions regarding Unusual Bird Reports received between 1 January 2021 and 31 December 2022. Among the 160 submissions accepted by the RAC were the first New Zealand records of black tern (Chlidonias niger), black-naped tern (Sterna sumatrana), and Matsudaira’s storm petrel (Hydrobates matsudairae). We also report the second accepted sightings of northern pintail (Anas acuta) and bridled tern (Onychoprion anaethetus), the third accepted sightings of long-toed stint (Calidris subminuta) and grey-backed tern (Onychoprion lunatus), and the third to fifth accepted records of Adelie penguin (Pygoscelis adeliae). Other notable records included the first record of long-tailed cuckoo (Eudynamys taitensis) from Campbell Island and of sooty tern (Onychoprion fuscatus) from the Chatham Islands.

Abstract: Wing areas and wing loadings of New Zealand land birds are poorly documented in the literature. I therefore report measured wing areas of 84 individual birds belonging to 27 species, with calculated wing loadings. Plotting the data graphically allows some ecological inferences. Heavier New Zealand land birds achieve greater wing loadings than lighter species, as is the case for birds generally. For flying birds, small passerines had the lowest wing loadings (0.12 g/cm2 for the New Zealand fantail) and heavier non-passerines the highest wing loadings (0.88 g/cm2 for the pukeko). I expected non-migratory, forest-dwelling, endemic song-birds with weak dispersal abilities to have very high wing loadings but this was not the case. Instead, native and introduced song-birds of similar size tended to have fairly similar wing loadings. Wing loading was slightly elevated in the North Island saddleback and North Island kokako but the whitehead was normal. The tui, a vigorous flier, had a much lower wing loading than expected for its mass. Data for three flightless species suggest that while high wing loading is an important correlate of flightlessness, it is not the only factor.