Gravel beaches are discrete, irregularly separated habitats along New Zealand’s coasts. They are one of a diverse range of small, disparate, naturally rare ecosystems that tend to occur in extreme environments, and provide critical habitat for threatened, rare and endemic species. New Zealand’s gravel beaches are threatened by urbanisation, weeds, adjacent agriculture, introduced animals and predicted sea-level rise.
Nectar is an important factor influencing the level and persistence of butterfly populations, but particular sources of nectar may not be optimal for all species. In a farmland context, it is not always clear whether nectar sources used by butterflies are good quality species. They may be used opportunistically in the absence of true preferences, therefore possibly limiting maximal reproduction.
Two conservation tools have been developed over the last 10–15 years for species on the New Zealand mainland that are vulnerable to introduced mammalian predators: landscape-scale predator trapping networks, and eradication of predators within mammal-proof exclosures. We tested whether these tools would allow population growth of critically endangered grand skinks (Oligosoma grande) and Otago skinks (O. otagense) over three years.
Invasive mammalian herbivores (e.g. deer, feral goats and brushtail possums; hereafter ‘herbivores’) are widespread throughout New Zealand and their control is important for conservation. In addition to known biodiversity benefits, it has recently been suggested that herbivore control could lead to measureable carbon gains when aggregated across a large area of conservation land. However, a significant amount of uncertainty exists regarding the potential effects of herbivore control on carbon, and the practicalities of successfully implementing such projects.
Kea (Nestor notabilis), large parrots endemic to hill country areas of the South Island, New Zealand, are subject to anthropogenic lead (Pb) exposure in their environment. Between April 2006 and June 2009 kea were captured in various parts of their range and samples of their blood were taken for blood lead analysis. All kea (n = 88) had been exposed to lead, with a range in blood lead concentrations of 0.014 – 16.55 ìmol L–1 (mean ± SE, 1.11 – 0.220 ìmol L–1). A retrospective analysis of necropsy reports from 30 kea was also carried out.
Conservation strategy for maintaining and protecting tuatara (Sphenodon punctatus), a rare endemic reptile from New Zealand, includes the reinstatement of populations through the past historical range. A proposal exists to translocate tuatara from Stephens Island in Cook Strait to the Orokonui Ecosanctuary (Te Korowai o Mihiwaka), a coastal site in southern New Zealand. The proposed site is within the former latitudinal range of the genus, but lies outside the current distribution of tuatara, where the climate is warmer.
A review of pest-exclusion fences throughout New Zealand shows that the goals of fence projects are frequently not achieved and cost-benefit analyses often do not adequately quantify ongoing costs. The creation of these sanctuaries enclosed by predator-proof fences often creates small expensive zoos surrounded by degraded habitat that will never be able to sustain the animal and plant species contained within the fence.
Opportunities now exist to establish pest-free areas on the mainland of New Zealand by eradicating introduced mammals from within predator-proof-fenced areas. This has increased opportunities to investigate how the native insect fauna responds to the eradication of introduced mammals. We examined the response of weta populations to mammal eradication in a before-after-control-impact (BACI) experiment within the southern exclosure on Maungatautari.
The contribution of exotic plantation forests to the conservation of New Zealand’s flora and fauna is a somewhat controversial issue, partly because the establishment of some plantations involved the conversion of indigenous vegetation. Such conversion no longer occurs within the professional forest industry and there is a growing appreciation of the contribution of ‘production’ land, including plantation forests, to the protection of New Zealand’s unique indigenous biodiversity.
Reintroduction programmes need to be monitored as a way of gauging potential causes of their success or failure. This, in turn, can be used to improve the likelihood of future translocation success. Since the 1990s, stitchbird (or hihi: Notiomystis cincta) translocations have been intensively monitored, with comparisons between two of these projects (Tiritiri Matangi Island – a successful introduction, and Mokoia Island – an unsuccessful introduction) often compared and contrasted as a means of identifying factors important in translocation success for this species.