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.
Mohua (Mohoua ochrocephala) are endemic to the South Island of New Zealand but they have declined in both range and abundance. The causes of decline include predation from introduced predators and forest clearance. Mohua have survived in reasonable numbers in the Dart Valley in west Otago. In this paper we describe the relationship between the presence of mohua breeding territories and vegetation at a 1 ha scale within low altitude, red beech-dominated forest. The extent of shrub or regeneration was found to have the strongest association with the presence/absence of breeding mohua. Other factors which increase leaf volume, such as forest-edge and broken canopy were also important in explaining the presence of mohua. Milling was found to have a long lasting negative impact (>70 years) on mohua presence. Management which reduces grazing and increases the shrub and regeneration forest component is likely to increase mohua carrying capacity.
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.
Information on the relevant spatial scale for controlling pest birds causing significant crop damage is generally lacking. Here, we assess the potential of 2 radiotracking systems (hand-held vs. elevated twin-Yagi antennae) for monitoring pest bird ranging behaviour on and around an arable farm. Radio-transmitters were fitted to 19 European greenfinches (Carduelis chloris) in the summer and 25 house sparrows (Passer domesticus) in the winter. Greenfinches were most likely to be detected in or near Brassica seed crops, particularly on the study farm, but 12% travelled large distances (>3 km) between Brassica crops in the landscape. Even though house sparrow home ranges were widely dispersed across the landscape, most overlapped with the farm boundary and were positively associated with woody vegetation. Relative to hand-held antennae, the elevated twin-Yagi system increased the detection radius for tagged birds from 100 m to 2000 m and also the number of location data, albeit over a more restricted area.
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.
The diet of the Australasian gannet (Morus serrator) at Farewell Spit, New Zealand, was studied by the analysis of 70 regurgitations collected from the 1995 to 2001 breeding seasons. Surface schooling pilchard (Sardinops neopilchardus) was the main prey, followed by anchovy (Engraulis australis). The composition of the diet was similar in most seasons examined except in 1996 in which anchovy was the main prey item. Such a change in diet could be linked with a pilchard mass mortality in New Zealand in August 1995. The estimated annual prey consumption by birds at the Farewell Spit gannetry was 852 tonnes. Although annual catches of pilchard and anchovy by commercial fisheries in the area are still relatively small, an increase may interfere with prey availability, and in turn, increase competition between marine predators and influence the breeding success. Our analyses of diet are consistent with previous studies showing that Australasian gannets as flexible foragers and they highlight their importance as bioindicators of fish stocks in New Zealand.