Suchergebnisse

Intro -- Foreword -- Preface -- History Is Important -- What This Book Is, and Is Not -- Predator-Free New Zealand 2050 -- Acknowledgements -- Contents -- About the Author -- List of Figures -- List of Tables -- Part I: The Years Before Cook -- Chapter 1: Introduction (82 Million Years Ago to AD 1280) -- Life on a Lonely Island -- The Story of New Zealand Wildlife -- The Gondwanan Fauna (82-c.55 Million Years Ago) -- The Zealandian Fauna (55-25 Million Years Ago) -- The Late Tertiary Fauna (25 Million-11,700 Years Ago) -- The Holocene Fauna (11,700 Years Ago to the Present) -- Advantages and Perils of Flightlessness -- Summary -- Chapter 2: The Māori Era (1280-1769) -- Aotearoa Discovered by People -- Pacific Rat, Kiore -- Polynesian Dog, Kuri -- The Fourteenth-Century Transformation -- Losses of Endemic Birds -- Moa Hunting -- Aotearoa at the Height of the Classic Māori Era -- Summary -- Part II: The Years of Accidental Invasions -- Chapter 3: Reconstructing Invasion Histories from European Shipping Records (1769-1900) and Genetics (Since 2000) -- Shipping Records -- Establishment of the Port of Sydney, 1788 -- Imported Food Supplies and Rodent Invasion Opportunities, 1788-1820 -- The China Fur Market, 1790-1810 -- Sealing and Whaling in Southern New Zealand, 1792-1830s -- The Development of Trans-Tasman Trade, 1800-1840 -- Outlying Islands -- Genetics as a Historical Tool -- Summary -- Chapter 4: European Rats (Since 1769) -- Norway Rats -- Norway Rats on Sailing Ships -- Norway Rats in New Zealand -- Kāpiti Island -- Campbell Island -- Ship Rats -- Ship Versus Norway Rats on Ships -- Competition Between Norway and Ship Rats -- Ship Rats in New Zealand -- Big South Cape Island (Taukihepa) -- Rats Versus Mustelids -- Summary -- Chapter 5: House Mice (Since About 1792) -- History of West European Mice in New Zealand.

Infrared (wavelengths >750 nm) light-emitting equipment is commonly used worldwide to monitor nocturnal predator and prey behaviour. However, it is possible that the infrared (IR)-light wavelengths emitted from the equipment are so close to the spectral threshold of some key species that the light may be detected. An operant procedure was used to test whether five male ferrets (Mustela furo) could see an IR light with peak wavelengths of 870 and 920 nm. First, the ferrets were taught to press a lever under a lit white light for food reinforcement (overall mean response accuracy was 89%). Changing the properties (wavelength and intensity) of the light did not disrupt the ferrets' abilities to perform the learned task. When the light was changed to IR (870 nm), four of five ferrets responded to the light at levels significantly higher than chance (mean = 68%, n = 4188, P < 0.01). When glare from a red trial-starting light was removed, two of the five ferrets (S3 and S4) showed strong evidence (response accuracies of 84% and 78%, respectively, P < 0.01) that they could see IR at 870 nm; however, S3 definitely could not see IR at 920 nm (n = 124, mean = 47%, P = 0.53). We conclude that at least some ferrets can see the light emitted from standard monitoring equipment that uses IR wavelengths of ~870 nm. To ensure nocturnal predator and prey behaviours are not altered by IR surveillance, field programs should use only high-wavelength IR diodes (at least 920 nm).

This book offers a sweeping history of Pureora Forest Park, one of the most significant sites of natural and cultural history interest in New Zealand. The authors review the geological history of the volcanic zone, its flora and fauna, and the history of Maori and European utilization of forest resources. Chapter-length discussions cover management of the native forest by the New Zealand Forest Service; the forest village and its sawmills; the intensive timber harvesting, and the conflicts with conservationists and expensive compensation agreements that ensued. Separate chapters cover initiatives to protect the forest from introduced herbivores; to guard protected species, especially birds, from predators; the facilities for recreational hunting; the development of the Timber Trail, an 83 km cycleway through the forest and along old logging tramways, complete with detailed interpretation signs illustrating the history of logging; and the family recreation areas and tracks. The final chapter gathers conclusions and advances prospects for the future of Pureora Forest. In sum, the book demonstrates how ecological study, combined with a respect for people and for nature plus a flexible, interdisciplinary approach to both local history and current scientific priorities, can be welded into a consistently effective strategy for addressing the pressing forest-ecology questions of our time

Pest mammals are completely excluded from Maungatautari Ecological Island, New Zealand, by a 47-km Xcluder pest-proof fence; however, they are commonly sighted directly outside, along the fenceline. Permanent pest exclusion relies on maintaining fence integrity, and enhancing knowledge of pest activity and behaviour at fenced reserves. We describe summer and winter periods of activity and behaviour of mammalian pests directly adjacent to the pest-proof fence. We (1) tested for the effects of adjacent habitat type, breach type and season on the rate of mammalian pest sightings directly at the fence, (2) determined how quickly pest mammals may locate a fence breach, and how likely they are to exploit it, and (3) developed a predictive model to help assess the probability of a pest gaining entry to the sanctuary if repair to a fence breach is delayed. Observations inside the rolled fence hood provided firm evidence that rats travel and forage extensively in this artificial although highly acceptable aboveground habitat, much more than on the ground. We confirm and emphasise that mammalian pests are constantly testing the pest-proof fence. Pests are very common directly outside the fence, and within 24 h there is a very high likelihood that a fence breach will be located and exploited. The greatest threat of reinvasion comes (1) nocturnally, (2) from rodents and (3) in the summer; however, these results also confirm that there is constant risk from multiple pest species, regardless of time of day or season.

Context. Relative density indices assuming uniform distribution of the target species are often the only cost-effective method for monitoring a population over the long term and at landscape scale, and the only source of valuable historical data. Yet, theoretical models emphasise the dangers of ignoring spatial heterogeneity, especially in short-term field data.
Aims. To test whether Brown's index of patchiness (BIP) can offer a simple means of checking rodent and mustelid survey data for violations of the assumption of uniform distribution.
Methods. We use BIP to interrogate long-term legacy data collected by index trapping of mice (Mus musculus), rats (Rattus rattus and R. norvegicus) and stoats (Mustela erminea) in New Zealand forests.
Key results. We found evidence of moderately patchy distributions that were independent of abundance in all three species. In two South Island beech (Nothofagus) forest valleys, 19% (6 of 31) of mouse samples and 8% (3 of 36) of stoat samples were significantly patchy, correlated with a seedfall event; in mixed forest at Pureora in the North Island, significant patchiness in distribution of ship rats was recorded in 19% (16 of 84) of Fenn trap samples and 5% (2 of 42) of rodent trap samples.
Conclusions. Moderate patchiness is common. The consequences for any given study depend on the purpose of the work, but may be more important for practical management than for population modeling.

The technique most widely used to control the stoat, an introduced predator in New Zealand, is to set Fenn (kill) traps, usually in lines or (less often) in grids. There has been no analysis of trap response in stoats, nor of the extent of potential variation in probability of capture. We report the results of an analysis of mark–recapture data recorded from stoats observed during a period of high stoat and mouse density in January 1980 in the Eglinton and Hollyford Valleys (northern Fiordland), using livetraps set in lines at one per 400 m over 14 km in each valley. Over 8 days of trapping (1–11 January), 89 stoats were tagged. The daily probability of first capture for all ages, both sexes, was 0.14 (with 95% confidence intervals 0.07–0.25) and of recapture 0.10 (0.07–0.14).We also analysed a new set of mark–recapture data collected during a period of very low mouse density in the Grebe Valley (southern Fiordland) in December 2000, using 19 live-traps set in a line at one per kilometre over 20 km. In this study 21 adult stoats and no young of year were tagged. The daily probability of first capture for adult males was 0.12 (0.04–0.31), and of recapturing them, 0.15 (0.10–0.23). A month later, in late January 2001, 68 Fenn traps set at four per kilometre caught 48 previously unmarked stoats, plus 12 of the 21 marked stoats released alive.Heterogeneity in probability of recapture was investigated by taking a longer subset of the 1980 data (1–17 January) and grouping individuals by sex and age. In the best closed-captures models, ranked using AICc, first-capture probability was similar for all stoats (0.17 (0.12–0.24)), and evidence of variation in the probability of recapture between age and sex classes was present but weak. The confidence limits around the recapture probabilities for adult males and females overlapped completely. Recapture probabilities for young-of-the-year males remained about the same (0.14 (0.11–0.19)), while the recapture probability of young-of-the-year females halved after first capture (0.07 (0.04–0.11)).Pledger's finite-mixture models demonstrating individual heterogeneity in trappability produced lower AICc values than the closed-captures models partitioning variation in recapture probability by age and sex alone. The observed heterogeneity in trap response is therefore not due only to variable individual response to traps, but is also to opportunity, as might be expected in data collected from a line of traps where the edge effect on trap-encounter rate is high. However, the extent to which trap-encounter rate helps to explain the observed heterogeneity is unknown. Indeed, there may be other sources of individual heterogeneity that are not related to age/sex or to trap-encounter rate, and this is a potential problem for wildlife managers using conventional trap lines to remove stoats to protect native species.

Context
Management of suites of invasive mammal species can lead to perverse outcomes, such as meso-predator release, or can achieve desirable reductions in the abundance of top-order predators by controlling their prey. Predictive models for predator–prey systems require estimates of predator functional responses, i.e. predation rates as functions of prey density.

Aims
In New Zealand, estimates of the functional responses of stoats (Mustela erminea) to mice (Mus musculus) and ship (black) rats (Rattus rattus) are required to improve management models for these invasive species.

Methods
We derived fitted relationships between the presence or absence of mouse or ship-rat remains in stoat guts and corresponding indices of prey abundance in beech and podocarp forests, respectively. To convert field data on stoat-gut contents to minimum kill rates, we used data on feeding activity and estimates of gut-passage time, observed in captive stoats.

Key results
The most parsimonious fitted curves were Type II functional responses, with a steeper stoat–mouse curve for autumn–winter, indicating a more specialist feeding habit than that in spring–summer. Estimated kill rates of mice per stoat per day reached an asymptote of 1.13 during autumn–winter. Our maximum observed kill rate for spring–summer was 11% less than the extrapolated upper limit of 1.04 mice per stoat per day for New Zealand ecosystems. No asymptote was reached within the limits of the data for the stoat–rat relationship.

Conclusions
Recent models for trophic interactions between stoats and the primary rodent prey have overestimated kill rates by stoats in forested ecosystems, particularly at very low and very high densities of mice. We show how data on stoat-gut contents can be rescaled to estimate minimum kill rates of rodent prey.

Implications
The functional-response relationships we have derived can be used to improve modelled predictions of the effects of natural or management-driven perturbations of invasive stoats and their primary rodent-prey populations.