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Many neglected tropical zoonotic pathogens are maintained by introduced mammals, and on islands the most common introduced species are rodents, cats, and dogs. Management of introduced mammals, including control or eradication of feral populations, which is frequently done for ecological restoration, could also reduce or eliminate the pathogens these animals carry. Understanding the burden of these zoonotic diseases is crucial for quantifying the potential public health benefits of introduced mammal management. However, epidemiological data are only available from a small subset of islands where these introduced mammals co-occur with people. We examined socioeconomic and climatic variables as predictors for disease burdens of angiostrongyliasis, leptospirosis, toxoplasmosis, toxocariasis, and rabies from 57 islands or island countries. We found strong correlates of disease burden for leptospirosis, Toxoplasma gondii infection, angiostrongyliasis, and toxocariasis with more than 50% of the variance explained, and an average of 57% (range = 32–95%) predictive accuracy on out-of-sample data. We used these relationships to provide estimates of leptospirosis incidence and T. gondii seroprevalence infection on islands where nonnative rodents and cats are present. These predicted estimates of disease burden could be used in an initial assessment of whether the costs of managing introduced mammal reservoirs might be less than the costs of perpetual treatment of these diseases on islands.

Predators play a critical role in ecosystems; however, when overly abundant, they can disrupt natural processes and cause extinctions of species. In particular, oceanic islands have endured many impacts of introduced mammalian predators. Whereas knowledge and management of introduced mammalian predators on islands is well advanced in natural landscapes, in inhabited landscapes, spanning rural and urban environments, comparatively less is known. We summarise key issues from the natural and social sciences in the management of introduced mammalian predators in inhabited landscapes of Aotearoa–New Zealand. We describe the shift in focus over the past few decades from management of introduced mammalian herbivores to predators in rural environments, and the growth in management of introduced mammalian predators in urban environments, both seeking to emulate conservation gains made in forested landscapes. We discuss the circumstances around companion animal management at the interface of the natural and social sciences. We summarise surveys of attitudes towards introduced mammalian predators, the role of biodiversity comanagement between Ma¯ori and Pakeha, and the importance of also considering non-biodiversity benefits from introduced predator management. We describe the rise of community predator control and large landscape projects aspiring for a ‘Predator Free New Zealand’, and how such an aspiration must be concurrent with habitat restoration. We make recommendations for further research on the basic population biology of predators in inhabited landscapes, and more long-term studies. Such studies should be integrated with examination of the motivations for predator management, as well as the biodiversity and social outcomes of such management. We conclude by remarking that introduced predator management is only one component of a robust national strategy for conservation of native biodiversity in New Zealand.

Eradication of introduced species from inhabited islands requires consideration of both technical and social feasibility. Historically, biologists have struggled to engage successfully in the social components of eradication planning. Island communities have unique features that require consideration in eradication planning. Social impact assessment is a powerful planning tool used widely outside of wildlife management. We outline the core components of a social impact assessment as it could be applied to eradication planning on inhabited islands. We summarise previous experience in social impact assessment and community engagement for introduced predator eradication on inhabited islands, and as an example develop a social profile for inhabited islands of the Hauraki Gulf of New Zealand. We conclude that social impact assessment has great potential to improve eradication feasibility assessment, and should be applied routinely in eradication scoping on inhabited islands.

The eradication of some introduced pests such as rats, stoats and possums in New Zealand seems increasingly feasible with successful action to date in various cities (e.g. Wellington City) and with the government’s national 2050 predator-free goal. Here we specifically detail the potential benefits of urban rat eradication and find these cover a wide range of topics including a potentially reduced risk of infection from at least seven zoonotic diseases (e.g. leptospirosis, toxoplasmosis, trichinellosis, murine typhus; and three enteric diseases). Other potential benefits include: psychological benefits from increased native bird life in cities; reduced damage to food supplies; reduced rat damage to building insulation and to building walls and roofing; and reduced fires in buildings associated with rat damage. However, there is considerable uncertainty on the size of such impacts and so we outline a tentative research agenda as a first step towards quantification of the likely key public health benefits of rat eradication.

Invasive alien species (IASs) on islands have broad impacts across biodiversity, agriculture, economy, health and culture, which tend to be stronger than on continents. Across small-island developing states (SIDSs), although only a small number of IASs are widely distributed, many more, including those with greatest impact, are found on only a small number of islands. Patterns of island invasion are not consistent across SIDS geographic regions, with differences attributable to correlated patterns in island biogeography and human development. We identify 15 of the most globally prevalent IASs on islands. IAS impacts on islands are exacerbated through interactions with a number of other global change threats, including over-exploitation, agricultural intensification, urban development and climate change. Biosecurity is critical in preventing IAS invasion of islands. Eradication of IASs on islands is possible at early stages of invasion, but otherwise is largely restricted to invasive mammals, or otherwise control is the only option. Future directions in IAS management and research on islands must consider IASs within a broader portfolio of threats to species, ecosystems and people’s livelihoods on islands. We advocate for stronger collaborations among island countries and territories faced with the same IASs in similar socio-ecological environments.

Global biodiversity loss is disproportionately rapid on islands, where invasive species are a major driver of extinctions. To inform conservation planning aimed at preventing extinctions, we identify the distribution and biogeographic patterns of highly threatened terrestrial vertebrates (classified by the International Union for Conservation of Nature) and invasive vertebrates on ~465,000 islands worldwide by conducting a comprehensive literature review and interviews with more than 500 experts. We found that 1189 highly threatened vertebrate species (319 amphibians, 282 reptiles, 296 birds, and 292 mammals) breed on 1288 islands. These taxa represent only 5% of Earth's terrestrial vertebrates and 41% of all highly threatened terrestrial vertebrates, which occur in 1% of islands worldwide. Information about invasive vertebrates was available for 1030 islands (80% of islands with highly threatened vertebrates). Invasive vertebrates were absent from 24% of these islands, where biosecurity to prevent invasions is a critical management tool. On the 76% of islands where invasive vertebrates were present, management could benefit 39% of Earth’s highly threatened vertebrates. Invasive mammals occurred in 97% of these islands, with Rattus as the most common invasive vertebrate (78%; 609 islands). Our results provide an important baseline for identifying islands for invasive species eradication and other island conservation actions that reduce biodiversity loss.

Disturbances that remove primary producers and alter substrate chemistry commonly influence ecosystem carbon dynamics. Because coastal wetlands are especially effective in sequestering carbon, quantifying how disturbances may alter their ability to perform this climate-regulating function is important for assessing their carbon storage potential. Here, we quantified soil respiration, litter decomposition, and soil organic carbon (SOC), as a proxy for carbon storage, in areas disturbed by invasive feral hogs Sus scrofa and in adjacent, undisturbed areas within 3 southeastern US salt marshes. Contrary to our hypothesis that hog overturning of soils would stimulate soil respiration, this metric was lower and both surface and subsurface litter decomposition rates were similar in disturbed relative to undisturbed areas across all sites. SOC was lower in disturbed versus undisturbed areas at 2 sites as hypothesized, but higher at 1 site. Surveys and analyses reveal that lower and less variable infauna, plant, and benthic algae densities likely suppressed soil respiration in hog-disturbed versus undisturbed areas, while the offsetting effects of lower invertebrate densities and higher soil temperature likely caused decomposition to be consistent within and outside of disturbed areas. . These findings suggest that hog removal of plants and disruption of soils can cause tracts of marsh to transition from carbon sinks to sources where these disturbances are intense enough to prohibit rapid plant recovery and promote the gradual respiration of carbon stocks from denuded soils.

Where conservation status of island non-marine molluscs is known, snails tend to be one of the most threatened faunal groups. However, published information regarding island gastropod conservation status, diversity and endemism is frequently unavailable despite the importance of this information for the formulation of biodiversity action plans and conservation strategy. Fiji, for example, has a diverse native land snail fauna (.240 species) with an endemism level of ,80%, but only within the last few years has any information about any of these species been available to the national biodiversity reporting repository. For one lineage in particular, members of the tree snail family Partulidae, with four endemic Fiji Island species, the conservation status of the group has never been assessed. However, based on the alarming extinction rates documented in partulid snail species on other Pacific Islands, information about the occurrence and status of these taxa is urgently needed for Fiji’s biodiversity action plan. To redress this information void, we formulated the Fijian Partulid Tree Snail Project, consisting of five components: (1) raising awareness; (2) locating populations and monitoring population trends; (3) elucidating patterns of genetic diversity; (4) creating action partnerships; and (5) conducting disturbance gradient analyses. The overall goal was to characterise mechanisms leading to persistence of partulids in the face of increasing anthropogenic disturbance. In the initial stages of this project, existing information on Fiji’s partulids was collated and two small, remote islands in the Fiji archipelago were surveyed to investigate whether tree snails persisted there. Living populations of Partula lanceolata and empty shells of Partula leefei were found on Cicia Island in Lau, and on Rotuma Island in the Rotuma Group, respectively. DNA analyses confirm a sister relationship between the two Partula species in north-eastern Lau, P. lirata and P. lanceolata, with both sharing a sister relationship with a member of the same genus in Vanuatu – P. auraniana Hartman, 1888. Prioritisation and further sampling of additional islands, and residual native habitat on less accessible islands and islets, is needed to fully assess the conservation status of all four Fijian species via the IUCN Red List process. Moreover, the basic descriptive information and associated studies reported here will serve to raise awareness of Fiji’s endemic tree snails particularly in communities that had no prior knowledge of their special conservation status; and also at a wider national, regional and global level. Community awareness is particularly vital as the willing support of land owners in the relevant small island communities is critical to implementing any future conservation action plans.

Harvesting, consumption and trade of forest meat are key causes of biodiversity loss. Successful mitigation programs are proving difcult to design, in part because anthropogenic pressures are treated as internationally uniform. Despite illegal hunting being a key conservation issue in the Pacifc Islands, there is a paucity of research. Here, we examine the dynamics of hunting of birds and determine how these contribute to biodiversity loss on the islands of Samoa. We focus on the interactive efects of hunting on two key seed dispersing bird species: the Pacifc pigeon (Ducula pacifca) and the critically endangered Manumea or tooth-billed pigeon (Didunculus strigiristris). We interviewed hunters, vendors and consumers and analyzed household consumption. Results suggest that over 22,000 pigeons were consumed per year and this is by primarily the richest people across the country. Indeed, the wealthiest 10% of households consumed 43% of all wild pigeon meat, and the wealthiest 40% of households consumed 80% of all pigeons. The Manumea was shot by 33% (n = 30) of the surveyed hunters while pursuing the Pacifc pigeon.

1. Anthropogenic disturbances particularly affect biodiversity in sensitive freshwater ecosystems by causing species loss. Thus, measuring the response of species to multiple disturbances is a key issue for conservation and environmental management. 2. As it is not practical to assess the response of every species in a community, we compared the performance of trait and taxonomic-based groupings of species for their abilities to predict species loss in a threatened freshwater fish assemblage. Specifically, we examined responses of a Fijian freshwater fish assemblage to deforestation, placement of anthropogenic barriers (overhanging culverts) and the presence of introduced cichlids. 3. Species grouped by traits showed more consistent responses to disturbances than taxonomic groups. In particular, species belonging to trait groups that were estuary associated favoured medium-to-hard substrate, while feeding specialists were highly likely to be absent in catchments with high deforestation and overhanging culverts. The presence of introduced cichlids (Oreochromis mossambicus and O. niloticus) had a smaller effect than deforestation and barriers, but was negatively associated with species richness of diadromous species with climbing ability and positively associated with presences of some piscivores. The trait groups also revealed that detritivores, species favouring soft substrate, and those with a broad dietary range were less sensitive to anthropogenic disturbances. 4. Our study indicates that using traits to predict species loss from disturbed environments can aid in detecting the responses of rare species to disturbance. In addition, we provided a method to estimate the consistency of species’ responses to disturbance. This study may ultimately help managers identify the most effective actions for conserving sensitive species that are seldom recorded in surveys.