A comparison of abundance and distribution model outputs using camera traps and sign surveys for feral pigs

Two raster datasets are included that were developed using data derived from game camera traps (Oahu_pigcam_distribution.tif) and visual sign surveys (Oahu_pigsign_distribution.tif). These data were used as inputs in a species distribution modeling approach using environmental correlates (please find more detailed information in the referenced publication). The resulting raster datasets are a relative abundance index (0 - 100) of feral pigs on Oʻahu.Species distribution models play a central role in informing wildlife management. For models to be useful, they must be based on data that best represent the presence or abundance of the species. Data used as inputs in the development of these models can be obtained through numerous methods, each subject to different biases and limitations but, to date, few studies have examined whether these biases result in different predictive spatial models, potentially influencing conservation decisions. In this study, we compare distribution model predictions of feral pig (Sus scrofa) relative abundance using the two most common monitoring methods: detections from camera traps and visual surveys of pig sign. These data were collected during the same period using standardised methods at survey sites generated using a random stratified sampling design. We found that although site-level observed sign data were only loosely correlated with observed camera detections (R2 ¼ 0.32–0.45), predicted sign and camera counts from zero-inflated models were well correlated (R2 ¼ 0.78–0.88). In this study we show one example in which fitting two different forms of abundance data using environmental covariates explains most of the variance between datasets. We conclude that, as long as outputs are produced through appropriate modelling techniques, these two common methods of obtaining abundance data may be used interchangeably to produce comparable distribution maps for decision-making purposes. However, for monitoring purposes, sign and camera trap data may not be used interchangeably at the site level

Minimizing species extinctions through strategic planning for conservation fencing

Conservation fences are an increasingly common management action, particularly for species threatened by invasive predators. However, unlike many conservation actions, fence networks are expanding in an unsystematic manner, generally as a reaction to local funding opportunities or threats. We conducted a gap analysis of Australia's large predator-exclusion fence network by examining translocation of Australian mammals relative to their extinction risk. To address gaps identified in species representation, we devised a systematic prioritization method for expanding the conservation fence network that explicitly incorporated population viability analysis and minimized expected species’ extinctions. The approach was applied to New South Wales, Australia, where the state government intends to expand the existing conservation fence network. Existing protection of species in fenced areas was highly uneven; 67% of predator-sensitive species were unrepresented in the fence network. Our systematic prioritization yielded substantial efficiencies in that it reduced expected number of species extinctions up to 17 times more effectively than ad hoc approaches. The outcome illustrates the importance of governance in coordinating management action when multiple projects have similar objectives and rely on systematic methods rather than expanding networks opportunistically

Standardized reporting of the costs of management interventions for biodiversity conservation

Effective conservation management interventions must combat threats and deliver conservation benefits at costs that can be achieved within limited budgets. Considerable effort has focused on measuring the potential benefits of conservation interventions but explicit quantification of implementation costs has been rare. Even when costs have been quantified, haphazard and inconsistent reporting means that published values are difficult to interpret. This reporting deficiency hinders progress towards building a collective understanding of the costs of management interventions across projects, and thus limits our ability to identify efficient solutions to conservation problems or attract adequate funding. We address this challenge by proposing a standardized approach to describing costs reported for conservation interventions. These standards call for researchers and practitioners to ensure the cost data they collect and report on provide enough contextual information that readers and future users can interpret the data appropriately. We suggest these standards be adopted by major conservation organizations, conservation science institutions, and journals, so that cost reporting is comparable between studies. This would support shared learning and enhance our ability to identify and perform cost-effective conservation.Funding was provided by CEED (GDI and workshop), an ARC Laureate Fellowship (HPP, BM, VA and JM), Arcadia (WJS), the Natural Environment Research Council (LVD, NE/K015419/1; NE/N014472/1) and the Wildlife Conservation Society (AJP)

Survival of a Laughing Kookaburra (Dacelo novaeguineae) after the predation of a Cane Toad (Rhinella Marina)

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Australian birds could benefit from predator exclusion fencing

The use of predator exclusion fencing is widely recognized as one of the most effective mechanisms for protecting threatened fauna from introduced or overabundant predators. It is now used throughout the world to protect avian fauna. In Australia, where predator exclusion fencing is used extensively to protect threatened mammals, such fences for threatened avifauna are surprisingly sparse. In this perspective we demonstrate that (a) the use of predator exclusion fences for avifauna is popular in other countries with similar conservation problems, (b) a large number of Australian avian species could benefit from dedicated predator exclusion fences, and (c) despite legitimate concerns, if well designed, predator exclusion fences can pose little risk to threatened birds or are outweighed by the potential benefits. We believe wider use of predator exclusion fencing to protect Australian threatened birds could be highly beneficial and should be more regularly considered as a management action by conservation practitioners

Understanding the importance of small patches of habitat for conservation

Conservation activities in fragmented landscapes have largely focused on keeping remaining large patches intact, often disregarding the increasingly important role of smaller patches in the conservation of remaining vegetation. As habitat loss proceeds in fragmented landscapes, there is an increasing need to measure the relative contribution of all patches (large and small) to overall ecosystem persistence, in a way that helps deliver effective conservation strategies aimed at preventing the death of ecosystems by a thousand cuts. Using Australian vegetation communities as a case study, we calculated the historical change in the contribution of patches below different sized thresholds to overall extent. We introduced a new patch assessment metric based on the Gini coefficient that indicates how unequal the distribution of patch sizes is relative to historical distributions. At least 22% of major vegetation communities in Australia have >50% of their remaining extent in patches </p

Protecting Australian mammals from introduced cats and foxes: the current status and future growth of predator-free havens

Many Australian mammal species are highly susceptible to predation by introduced cats (Felis catus) and European red foxes (Vulpes vulpes). At least 34 Australian endemic mammal species have been made extinct since 1788, about 10% of Australia’s terrestrial mammal. Predation by introduced cats and foxes was a major contributor to most of those extinctions. The Australian mammal extinctions make up about one-third of all global mammal extinctions over the last ca. 500 years. Cats and foxes have also driven large distributional and population declines for many more surviving species. Cats now occur across the entire Australian mainland and Tasmania, and are present on many of the larger islands