Publications Archive

We report a polymorphic population of collared petrels (Pterodroma brevipes) apparently breeding on Vanua Lava, northern Vanuatu, in the austral autumn-winter. This is one of only 5 known extant colonies of the species. One of the 2 birds captured by us matched the description of the recently described dark plumaged Pt. b. magnificens which had never been reported caught ashore previously. However, the other bird caught was a paler individual indicating that the taxon is variable in plumage colour, like other Pt. brevipes populations. We suggest that the 2 other criteria used to define the subspecies Pt. b. magnificens (body size and breeding chronology) are also questionable and require further investigation.

We report on the discovery, care, release, and post-release monitoring of the 2nd vagrant emperor penguin (Aptenodytes forsteri) recorded from New Zealand. An immature male emperor penguin came ashore at Peka Peka Beach (40° 50’ S) 56 km north-east of Wellington on 20 Jun 2011. Its condition deteriorated over the following 4 days, and it was taken into care at Wellington Zoo on 24 Jun. Following 72 days of rehabilitation, the bird was released at sea at 51° 42’ S, 78 km north of subantarctic Campbell I, on 4 Sep 2011. He was tracked, via satellite transmitter, moving south-east for 113 km until 9 Sep, after which no further signals were received. The arrival, care and release of this penguin attracted unprecedented levels of public and media interest for a vagrant bird to New Zealand.

Deliberate taxon substitution is a much discussed but rarely enactioned concept in restoration ecology. We describe the successful establishment of a translocated population of Snares Island snipe (Coenocorypha huegeli) on Putauhinu I, which lies alongside Taukihepa (Big South Cape I), the last stronghold of the extinct South Island snipe (C. iredalei). Thirty Snares Island snipe were captured on North East I, Snares Is in Apr 2005 and released 3-5 days later on Putauhinu I. A survey on Putauhinu I in Mar 2011 resulted in the capture of 54 descendants of the released birds and a population estimate of at least 320 birds. This is one of few documented translocations of an organism with the specific objective of replacing a closely related extinct taxon. As a result, the Snares Island snipe is probably more abundant than at any time in its evolutionary history.

To date there has been no published information describing the relative abundance, behaviour or distribution of the New Zealand king shag (Leucocarbo carunculatus) within mussel farm areas, despite the sensitivity of the species to human disturbance and the potential overlap of its range with proposed development of marine aquaculture. Four survey methods were employed as part of a multi-species research programme to develop methods for surveying marine mammals and seabird populations in aquaculture management areas. Two of the techniques, involving continuous time- lapse photography of mussel farms and boat-based surveys through coastal farms were developed for this study. Time- lapse cameras showed that mussel farms buoys were used by king shags as temporary resting sites only. King shags were recorded on 36% of the farms (n = 44) from 13 surveys within inner Admiralty Bay. The low number of sightings within mussel farms suggests that farms are not important foraging or resting areas for king shags, at least in Admiralty Bay. The foraging range and density of king shags was not known before farms were developed, so no direct comparison or impact assessment can be made. Boat-based surveys were used to estimate the density of foraging shags, which showed that daily locations of foraging birds at sea can vary considerably on consecutive days and over the season. Previous environmental surveys to assess impacts of mussel farms on foraging areas are therefore unlikely to adequately represent the entire foraging range or most important feeding areas. The number of breeding pairs, chicks and nests was also found to vary considerably at colonies, dependent on when counts were undertaken during their protracted breeding season. Open water mid-bay aquaculture (shellfish and finfish) potentially poses a greater threat to king shags than ‘coastal ribbon development’, in terms of loss of open water habitat from farm structures, and loss of foraging habitat through modification to the water column (e.g., turbidity) and seabed. Given the lack of knowledge about the king shag population dynamics, diet and prey availability, there is an urgent requirement for more research to fill these gaps and also understand how we can conserve important shag feeding areas and associated marine environment through sustainable management of aquaculture.

The South Island snipe (Coenocorypha iredalei) was described by Walter Rothschild in 1921 based on 3 specimens collected on Jacky Lee I, off Stewart I, in 1897 & 1898 and purchased from Henry Travers. The last 3 birds were seen 43 years later on Big South Cape I, and the species is considered extinct following introductions of weka (Gallirallus australis) or ship rats (Rattus rattus) to its 2 last strongholds. I surveyed surviving museum skins, literature, and personal accounts of the South Island snipe, including a previously unpublished account from the type locality, to learn more of the bird’s discovery and extinction. Seven only of the 24 known specimens had correct locality data associated with them; as a result, many were assumed until recently to be Snares Island snipe (C. huegeli). Based on specimen records, historic correspondence, and forensic examination of specimen labels, I conclude that Henry Travers never visited Jacky Lee I, and that the unknown collector of the type specimens of C. iredalei also collected bird specimens from Rangatira I in the Chatham Is in 1899 and 1900.

Sexual differences in vocalisations of the Vanuatu petrel (Pterodroma occulta) are described. Qualitative differences in burrow calls could be used to sex adults with 63-100% accuracy in listening experiments. Males sounded “clear” and females sounded “hoarse”. Higher accuracy is possible with the aid of spectrograms. Playback experiments demonstrated a male-bias in responses of incubating Vanuatu petrels to “war-whooping” and flight calls. Acoustic methods have practical and ethical advantages over handling breeding petrels and further studies of the vocal behaviour of gadfly-petrels are encouraged.

Edgar Stead (1881-1949) documented avian diversity on the islands around Stewart I during the 1930s and 1940s, and named 3 new passerine subspecies in 1936. Between 1912 and 1950, 6 other newly-recognised bird taxa were given the epithet ‘steadi’. Four of these were indisputably named after Edgar Stead: Stictocarbo steadi Oliver, 1930, Pseudoprion turtur steadi Mathews, 1932, Thalassarche cauta steadi Falla, 1933, and Petroica (Miro) australis steadi Fleming, 1950. Carbo carbo steadi Mathews & Iredale, 1913 was probably named after Edgar Stead. It is suggested that Procellaria aequinoctialis steadi Mathews, 1912 was most likely named after the Australian naturalist David Stead (1877-1957). Among the birds named by or for Edgar Stead, only Thalassarche cauta steadi Falla, 1933, Xenicus longipes variabilis Stead, 1936, and Bowdleria punctata wilsoni Stead, 1936 are recognised as valid taxa in the 2010 Checklist of the birds of New Zealand. Stictocarbo steadi Oliver, 1930 is permanently invalid. A list of type specimens collected by Stead is presented, representing 6 currently recognised taxa.

Food preferences of the bellbird (Anthornis melanura), an endemic honeyeater, were determined by comparing the proportional use of plant species for nectar, fruit, and invertebrate feeding with the proportional availability (foliar cover) of plant species in forest remnants on the Port Hills, near the city of Christchurch, New Zealand. Of 529 feeding observations throughout the year, 56% were on invertebrates, 29% on nectar, and 15% on fruit. Invertebrate feeding predominated in all months except August to November, when nectar feeding predominated. Kunzea ericoides, Fuchsia excorticata, and Hoheria angustifolia were used more than expected from their foliar cover for invertebrate feeding, while F. excorticata, Sophora microphylla, Pseudopanax arboreus, and Phormium tenax were used more than expected for nectar feeding, and Coprosma robusta and Myrsine australis more than expected for fruit feeding. Little nectar was available in winter, which may explain why some bellbirds moved from the hills to the city at the end of the breeding season. However, more research is needed on the influence of temperature on these movements and on the resources used by bellbirds in the city.