Amy L. Whitehead

Integrating Biological and Social Values When Prioritizing Places for Biodiversity Conservation

The consideration of information on social values in conjunction with biological data is critical for achieving both socially acceptable and scientifically defensible conservation planning outcomes. However, the influence of social values on spatial conservation priorities has received limited attention and is poorly understood. We present an approach that incorporates quantitative data on social values for conservation and social preferences for development into spatial conservation planning. We undertook a public participation GIS survey to spatially represent social values and development preferences and used species distribution models for 7 threatened fauna species to represent biological values. These spatially explicit data were simultaneously included in the conservation planning software Zonation to examine how conservation priorities changed with the inclusion of social data. Integrating spatially explicit information about social values and development preferences with biological data produced prioritizations that differed spatially from the solution based on only biological data. However, the integrated solutions protected a similar proportion of the species distributions, indicating that Zonation effectively combined the biological and social data to produce socially feasible conservation solutions of approximately equivalent biological value. We were able to identify areas of the landscape where synergies and conflicts between different value sets are likely to occur. Identification of these synergies and conflicts will allow decision makers to target communication strategies to specific areas and ensure effective community engagement and positive conservation outcomes.

Removal of livestock alters native plant and invasive mammal communities in a dry grassland-shrubland ecosystem

The impacts of domesticated herbivores on ecosystems that did not evolve with mammalian grazing can profoundly influence community composition and trophic interactions. Also, such impacts can occur over long time frames by altering successional vegetation trajectories. Removal of domesticated herbivores to protect native biota can therefore lead to unexpected consequences at multiple trophic levels for native and non-native species. In the eastern South Island of New Zealand large areas of seral grassland–shrubland have had livestock (sheep and cattle) removed following changes in land tenure. The long-term (>10xa0years) outcomes for these communities are complex and difficult to predict: land may return to a native-dominated woody plant community or be invaded by exotic plants and mammals. We quantified direct and indirect effects of livestock removal on this ecosystem by comparing plant and invasive mammal communities at sites where grazing by livestock ceased c.10–35xa0years ago (conservation sites) with paired sites where pastoralism has continued to the present (pastoral sites). There was higher total native plant richness and reduced richness of exotic plants on conservation sites compared with pastoral sites. Further, there were differences in the use of conservation and pastoral sites by invasive mammals: rabbits and hedgehogs favoured sites grazed by livestock whereas house mice, brushtail possums and hares favoured conservation sites. Changes in the relative abundance of invasive mammal species after removal of domesticated livestock may compromise positive outcomes for conservation in successional plant communities with no evolutionary history of mammalian grazing.

Variation in productivity of Grey-faced Petrels (Pterodroma gouldi) with local burrow density and breeding island

Abstract For long-lived birds, estimates of productivity can be effective indicators of environmental change or responses to management. Such estimates are also valuable in modelling population growth. We report estimates of nest survival for burrow-nesting Grey-faced Petrels (Pterodroma gouldi) from four islands off the north-eastern coast of New Zealand. We surveyed the contents of breeding burrows for up to four breeding seasons and followed the fates of 1371 eggs. We used a logistic-exposure modelling approach to investigate the effects of island, year, local burrow density and occupancy rate on nest survival. Daily nest survival varied between years and islands but declined with increasing local burrow density across all islands. Local burrow occupancy rate had no detectable effect. We estimated overall rates of breeding success on our island groups of 11% (95% confidence interval 9–14%) to 28% (26–30%). The negative density-dependent relationships between local burrow densities and productivity add to the growing evidence for this effect in burrow-nesting seabirds worldwide, in contrast to trends in surface-breeding species. The variation in productivity between our study colonies may be linked to the restoration histories of the islands and suggests that data from one location should be used cautiously when guiding management of the same species elsewhere.

South Polar Skua breeding populations in the Ross Sea assessed from demonstrated relationship with Adélie Penguin numbers

In the Ross Sea region, most South Polar Skuas (Stercorarius maccormicki) nest near Adélie Penguin (Pygoscelis adeliae) colonies, preying and scavenging on fish, penguins, and other carrion. To derive a relationship to predict skua numbers from better-quantified penguin numbers, we used distance sampling to estimate breeding skua numbers within 1000xa0m of 5 penguin nesting locations (Cape Crozier, Cape Royds, and 3 Cape Bird locations) on Ross Island in 3 consecutive years. Estimated numbers of skua breeding pairs were highest at Cape Crozier (270,000 penguin pairs; 1099 and 1347 skua pairs in 2 respective years) and lowest at Cape Royds (3000 penguin pairs; 45 skua pairs). The log–log linear relationship (R2xa0=xa00.98) between pairs of skuas and penguins was highly significant, and most historical estimates of skua and penguin numbers in the Ross Sea were within 95xa0% prediction intervals of the regression. Applying our regression model to current Adélie Penguin colony sizes at 23 western Ross Sea locations predicted that 4635 pairs of skuas now breed within 1000xa0m of penguin colonies in the Ross Island metapopulation (including Beaufort Island) and northern Victoria Land. We estimate, using published skua estimates for elsewhere in Antarctica, that the Ross Sea South Polar Skua population comprises ~50xa0% of the world total, although this may be an overestimate because of incomplete data elsewhere. To improve predictions and enable measurement of future skua population change, we recommend additional South Polar Skua surveys using consistent distance-sampling methods at penguin colonies of a range of sizes.

Grey-faced petrel (Pterodroma gouldi) productivity unaffected by kiore (Pacific rats, Rattus exulans) on a New Zealand offshore island.

Burrow-nesting seabird populations are vulnerable to predation by introduced rats, because of their nesting habits and slow life histories. We investigated whether control of kiore (Pacific rats, Rattus exulans) by removal trapping, and during an unsuccessful community-led island-wide eradication attempt, had any effects on nest survival of grey-faced petrels (Pterodroma gouldi) on Ririwha (Stephenson Island), northeastern New Zealand. We compared nest survival between two plots at which rats were trapped and six un-trapped plots in 2010, as well as at all plots during and after the poisoning programme in 2011–2012. Neither mean rates of breeding burrow occupancy nor nest survival differed between trapped and un-trapped plots in 2010. We found no significant differences between years or between plots throughout the poisoning programme. Extrapolation of daily nest survival rates to the full 172-day combined egg and chick period gave an estimate of mean annual productivity for all plots combined of 0.285 (95% confidence interval 0.252–0.318), which is higher than on comparable predator-free islands. Although the absence of a detectable effect of kiore on breeding grey-faced petrels on Ririwha is reassuring, we can be less sure that smaller burrow-nesting seabirds on the island are secure.

Communicating biophysical conditions across New Zealand's rivers using an interactive webtool

ABSTRACT Scientific research is often targeted towards predicting broad-scale patterns in biophysical variables, with spatial data traditionally communicated using static figures and written descriptions in scientific journals and reports. However, inaccessibility and lack of flexibility mean that these communication methods have often hindered research uptake by resource managers and decision-makers. We used R shiny to develop an interactive webtool that maps estimates of 109 biophysical variables, including hydrology, ecology and water quality metrics across the New Zealand digital river network. NZ River Maps is freely available online and can be used to visualise regional patterns, identify site-specific characteristics and overlay regional planning layers. Interactive webtools improve on traditional communication methods by allowing inspection of predictions for selected sites and plotting of spatial patterns. The ability to quickly visualise and quantify relevant spatial data has enabled better communication of research outputs to provide robust and transparent inputs into environmental management.