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.
New Zealand conservation managers have a distinguished history in translocating forest birds, shorebirds and waterfowl to achieve conservation gains. Although New Zealand is a centre of seabird diversity, and many species are threatened and/or have suffered human-induced range reductions, until recently there had been few attempts to translocate seabirds. Reluctance to attempt translocations was due largely to the perceived risk of dispersal, and the expectation that birds would return to their source colony. Translocations have now been attempted with 10 species of burrow-nesting petrels in New Zealand, with chicks moved before they were likely to have developed awareness of their natal colony location, and hand-fed until they fledged. The translocation of 240 fairy prion chicks from Takapourewa (Stephens I) to Mana I in 2002-04 was one of few petrel translocation studies where systematic searches for returning translocated chicks at both the release site and the source colony were undertaken, and where a sample of marked control chicks allowed comparison of natural return rates with those of translocated chicks. Twenty translocated chicks returned to Mana I during 2004-12, and 25 were recovered at the source colony during 2005-08. Nearly identical proportions (c.20%) of translocated and control chicks were recovered, with higher recovery rates at the release site for each successive cohort. Birds appeared to develop their homing ability at different ages, and there was no apparent maximum age after which chicks should not be translocated. Exposing chicks to the source colony surface in daylight did not increase the risk of them returning to the source colony.
Translocations (deliberate movement and release of wildlife) have been of crucial importance in the management of New Zealand threatened birds, and as part of site restoration projects. We review attempts to translocate New Zealand birds for conservation reasons since 1863. Following an early pulse from 1895-1908, there was concerted and increasing effort (both in the number of translocations and the number of taxa translocated) and success since the early 1960s. Sixty- eight taxa (55 species) of New Zealand birds have been translocated in over 1100 separate releases, with new populations of 50 taxa (41 species) successfully established. Translocations of 9 further taxa (7 further species) are in progress. Overall, 61% of New Zealand’s extant endemic waterfowl, shorebird and landbird taxa have been translocated (51% of the total successfully, with an additional 4% in progress). Five taxa exist solely as translocated populations (little spotted kiwi Apteryx owenii, buff weka Gallirallus australis hectori, kakapo Strigops habroptilus, South Island saddleback Philesturnus carunculatus and black robin Petroica traversi), and 10 further taxa would be confined to single wild populations but for successful translocations. Most translocations were undertaken within historical ranges, however, 6 taxa have been established beyond their historical ranges, with attempts for 2 further taxa in progress.