Publications Archive

Abstract: Coastal and nearshore habitats are important to all seabird species. Understanding the distribution of seabirds in these environments can aid in their conservation. Despite the importance of coastal habitat, data collection for seabird species at sea is often difficult and resource intensive. Here, we take advantage of an established marine mammal surveying programme to collect distribution data for seabird species encountered in nearshore habitat. We surveyed seabird communities over 76 days in four locations along the southeast coast of New Zealand’s South Island; Dunedin, Moeraki, Timaru, and Banks Peninsula. We present observations of seabird species presence in these locations, as well as, a brief assessment of the counting techniques used during the study. In addition, we summarise the seabird numbers in relation to the marine mammal surveys (i.e. the presence and absence of dolphins). We aim to show the value of opportunistic data collection, while contributing to baseline species distribution knowledge.

Egg floatation is a technique which can be used to estimate egg age and hatching dates of New Zealand shorebird eggs. It can be used to improve the accuracy of nest survival models, help identify nest outcomes, assist with chick survival monitoring and to prioritise the capture of incubating birds. We used egg floatation to estimate the age and hatching dates of South Island pied oystercatcher (Haematopus finschi) (SIPO) eggs. We developed regression equations to estimate the age of SIPO eggs by modelling egg angle and egg float height against egg age using a sample of eggs with known hatch dates. For early incubation eggs, we used linear regression to model the relationship between egg age and egg angle only, whereas for late incubation eggs we used multiple regression to model the relationship between egg age and both egg angle and egg float height data. These equations allowed 90% of SIPO eggs to be aged to within five days of their actual age. We recommend that species-specific regression equations describing the relationship between egg float characteristics and egg age be developed for other New Zealand shorebird species, to aid future research, monitoring and conservation management actions on these species.

Abstract: Observations were made of the Nationally Vulnerable Hutton’s shearwater (Puffinus huttoni) breeding at Te Rae o Atiu, Kaikōura Peninsula (42.429°S, 173.703°E), New Zealand, a new colony established by translocations where birds breed in nestboxes. Over 12 seasons there were 245 eggs laid, including seven instances of two eggs laid as separate clutches in one nestbox during the same season. Nestbox inspections, usually undertaken weekly, provided evidence of egg laying date. Bird attendance at the nestboxes was also obtained from implanted passive integrated transponders that triggered a reader and datalogger. There is evidence for birds re-laying an egg after the first egg failed for three separate events, and a fourth was a possibility. In three other events, it appears more likely that two different birds laid the eggs, two as female-female pairings or simply egg dumping by an unpaired female; the third event was inconclusive. Only one of the 14 eggs from two-egg nests hatched, and the chick fledged successfully, about 10 days later than any other chick recorded at this colony. This fledging date was similar to the last date for fallout birds from the natural, mountain colonies, and suggests that re-laying may be a natural consequence of early egg failures in this species.

The wrybill | ngutu pare (Anarhynchus frontalis) is a small plover endemic to New Zealand with a unique laterally curved bill. Apart from moult, much of its biology is well understood: adults breed from late August to January on the braided river systems in Canterbury and inland Otago on New Zealand’s South Island. From midsummer, late December and January, they migrate north to non-breeding areas in the northern part of the North Island, especially to the large tidal bays, east and west of Auckland, where they undergo primary moult from January to April. The Underhill- Zucchini moult model was used to estimate the mean start and completion dates of primary moult, which were 20 January and 3 April respectively. Adults thus commence primary moult soon after arrival on non-breeding grounds but complete moult around four months before southward migration to their breeding areas in August. They appear to avoid primary moult during winter. Second-year birds start primary moult in December, one month earlier than the adults, but finish at approximately the same time. Primary moult of the wrybill is compared with closely related species, and with other waders that breed on the South Island and migrate to North Island for the non-breeding season.

Holdaway, R.N.; Allentoft, M. E. 2022. A basic statistical approach to determining adult sex ratios of moa (Aves: Dinornithiformes) from sample series, with potential regional and depositional biases. Notornis 69: 158-173.

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.