Aspects of the breeding biology of the grey petrel (Procellaria cinerea) were studied on Antipodes Island between April and June 2001. The island was surveyed to determine grey petrel distribution and four 2,500 m2 census grids were established. The survey suggested that the distribution of grey petrels was restricted to steep, well-draining areas dominated by Poa litorosa tussock (approximately 510 ha of the 2,025 ha island). Occupied burrow density within the 4 census grids ranged from 31 to 44 burrows (0.01 burrows per square metre). Extrapolating from the census grid density to the total grey petrel habitat resulted in a population estimate of 114,730 birds: 53,000 breeding pairs (range = 32,000- 73,000) and 8,670 non-breeding-birds (range = 4,000-16,320) were present on Antipodes Island. Aspects of the behaviour of the species were recorded. Comparisons are made with other members of the genus Procellaria.
The Chatham Islands tomtit (Petroica macrocephala chathamensis) is a small forest passerine with a threat ranking of nationally endangered. It is restricted to 2 islands of the Chathams group that are free of introduced predators (Rangatira and Mangere Islands), and 1 with mice (Mus musculus) and feral cats (Felis catus) (Pitt Island). We carried out a translocation of 35 juvenile tomtits from Rangatira (10 male, 10 female) and Pitt Islands (6 male, 9 female) to Awatotara Valley, Chatham Island in January 2011. Mean weight at capture of Pitt Island tomtits was lighter than that of the Rangatira Island tomtits. Tomtits were held captive in aviaries for 1-3 days on the source islands and 2-4 days at the release site. Weight loss of tomtits in captivity prior to transfer averaged 1.8% of body mass per day held and was more pronounced in birds sourced from Rangatira than Pitt Island. Two birds died during the first night after transfer, but the other 33 were released in apparently good health. Eighteen of the released birds were seen at least once, and 11 regularly until 28 March (at least 55 days after release). During the following 12 days, all 11 of these tomtits disappeared. We discuss possible reasons for their disappearance, and aspects of the translocation that may be useful for future translocations of tomtits and other species with a similar ecology.
This paper surveys molecular and morphological work on parrots over the last 20 years and we show how it has re-shaped popular and scientific views regarding endemic New Zealand taxa. Recent research has shown the kakapo (Strigops habroptilus) is not closely related to apparent counterparts in Australia but in fact is a member of an ancient and exclusively New Zealand clade together with the kea and the kaka (Nestor spp.). Superficially similar Australian nocturnal taxa, the night parrot (Pezoporus occidentalis) and the ground parrot (P. wallicus) are members of an altogether different family. At the same time, the parrots as a worldwide group have more or less retained their sense of Gondwanan ancestry, but with an increased focus on Australasia as a centre of origin. The previous paradigm explaining contemporary parrot diversity that suggested evolution was brought about exclusively by vicariant speciation has been supplanted with a synergistic model of dispersal and vicariance following the demonstration that multiple dispersal events have occurred, for example from Australia across the chain of Indian Ocean Islands to Africa.
An annotated checklist of birds recorded or reported on the Aleipata Is, Samoa is presented. Nu’utele and Nu’ulua Is were the focus of an attempt to eradicate Pacific rats (Rattus exulans) in 2009. The data presented are from bird surveys intended to provide baseline information to determine the effect of rodent eradication on the bird fauna. Fanuatapu or Namu’a Is were surveyed as experimental controls. A total of 42 species were recorded or reported, comprised of 24 species of land birds (including 3 introduced species) and 18 species of seabirds and shorebirds. Morphometric data are also presented from Friendly ground-doves (Gallicolumba stairi) that were removed from Nu’utele I and held in captivity during the rat eradication attempt.
Orange-fronted parakeets (Cyanoramphus malherbi) are New Zealand’s rarest parakeet species with a global population of less than 500 individuals on remnant mainland populations and reintroduced populations on offshore islands. Since there is limited information about habitat preferences by this species on offshore islands I characterised habitat use on Maud Island, where captive-bred parakeets were introduced in 2007. I compared the vegetation characteristics of 29 plots (each 25 m2) where parakeets were encountered and 23 plots randomly selected. Parakeets were observed foraging in 96.6% of the plots. Plots used by parakeets showed significantly higher density of stems under 20 cm dbh and a higher canopy than random plots. Used plots also tended to have greater canopy cover and lower understory and ground vegetation covers. These results indicate that orange-fronted parakeets use ecotones of broadleaf coastal forest-manuka scrub, and pine plantations-manuka scrub for foraging highlighting the potential value of islands with mixed patches of these vegetation types as future refuges for this critically endangered species.