Search

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: The world's islands support disproportionate levels of endemic avian biodiversity despite suffering numerous extinctions. While intensive recent research has focused on island bird conservation or extinction, few global syntheses have considered these factors together from the perspective of morphological trait diversity. Here, we provide a global summary of the status and ecology of extant and extinct island birds, the threats they face and the implications of species loss for island functional diversity. Location: Global. Taxon: Birds. Methods: We provide a review of the literature on threatened and extinct island birds, with a particular focus on global studies that have incorporated functional diversity. Alongside this, we analyse IUCN Red List data in relation to distribution, threats and taxonomy. Using null models and functional hypervolumes, in combination with morphological trait data, we assess the functional diversity represented by threatened and extinct island endemic birds. Results and main conclusions: We find that almost half of all island endemic birds extant in 1500 CE are currently either extinct or threatened with extinction, with the majority of threatened extant species having declining population trends. We also found evidence of 66 island endemic subspecies extinctions. The primary threats to extant island endemic birds currently are agriculture, biological resource use, and invasive species. While there is overlap between the hotspots of threatened and extinct island endemics birds, there are some notable differences, including the Philippines and Indonesia, which support a substantial number of threatened species but have no recorded post‐1500 CE bird extinctions. Traits associated with threatened island endemic birds are large body mass, flightlessness, aquatic predator, omnivorous and vertivorous trophic niches, marine habitat affinity, and, paradoxically, higher dispersal ability. Critically, we find that threatened endemics (i) occupy distinct areas of beak morphospace, and (ii) represent substantial unique areas of the overall functional space of island endemics. We caution that the loss of threatened species may have severe effects on the ecological functions birds provide on islands. [ABSTRACT FROM AUTHOR]

Wetlands, one of the most biodiverse ecosystems in the world, are increasingly subjected to area loss and degradation due to land-use and climate changes. These factors impact their unique biodiversity, including numerous invertebrates that depend on them. Here we investigated the current and future habitat suitability of the aquatic spiders Argyroneta aquatica and Dolomedes plantarius. We evaluated future trends in their geographic range, aiming at assessing their extinction risk according to the International Union for Conservation of Nature (IUCN) Red List criteria, at both global and regional levels. We investigated present and future distribution ranges using species distribution models for two integrated emission scenarios (SSP1-2.6 and SSP5-8.5) and combining three general circulation models. These were combined with knowledge on species' dispersal limitation to account for the possibility that these species will not be able to move beyond the current range in the next decades. We found a significant future northern shift in the geographic range and a global reduction in habitat suitability for both species, corresponding to a loss of 28.9 % for A. aquatica and 38.1 % for D. plantarius in the next 10 years. The application of the IUCN criteria qualifies A. aquatica as Near Threatened and D. plantarius as Vulnerable. Regional assessments provided similar patterns of range reductions and population vulnerability across all European regions, particularly for Central-Eastern and Western Europe. Conversely, Northern Europe is expected to become a climatic refugium for both species. This work goes beyond the available studies on the conservation of these species by taking account their dispersal abilities in quantifying future trends in their habitat suitability using the most up to date knowledge. Conservation strategies should be directed towards limiting the impact of climatic and non-climatic stressors on wetlands, and towards implementing management plans and restoration programmes to increase habitat suitability and connectivity among wetland patches. [Display omitted] • Argyroneta aquatica and Dolomedes plantarius are charismatic species of wetlands subjected to habitat loss and degradation. • A future northern shift in geographic range and a global reduction in habitat suitability is forecasted for both species. • The predicted loss is 28.9 % for A. aquatica and 38.1 % for D. plantarius in the next 10 years. • The application of the IUCN criteria qualifies A. aquatica as Near Threatened and D. plantarius as Vulnerable. • Regional assessments provided similar patterns of range reductions and population vulnerability across all European regions. [ABSTRACT FROM AUTHOR]

Abstract: The IUCN Red List is the most useful list of species that are at risk for extinction worldwide, as it relies on a number of objective criteria. Nevertheless, there is a taxonomic bias that excludes species with small body sizes, narrow distribution ranges and low dispersal abilities, which constitute the vast majority of the planet’s biota, particularly local endemics. By evaluating each IUCN criterion separately, we (i) identify the shortcomings for invertebrate applications, (ii) explain how risk categories may be wrongly applied due to inapplicable and/or misleading thresholds, (iii) suggest alternative ways of applying the existing criteria in a more realistic way and (iv) suggest possible new criteria that were not considered in the current evaluation framework but that could allow a more comprehensive and effective assessment of invertebrates. By adapting the criteria to rely more explicitly on the Area of Occupancy and the Extent of Occurrence, their respective trends and by using ecological modelling methods, the criteria’s applicability would be increased. The change in some thresholds or, eventually, the creation of sub-categories would further increase their adequacy. Additionally, co-extinction could be introduced as an explicit part of the classification process. As a case study, we evaluated 48 species of Azorean arthropods and Iberian spiders according to the current criteria. More than one-quarter (27%) of all evaluated species were classified as Critically Endangered, 19% as Endangered, 6% as Vulnerable and 8% as Least Concern. The remaining 40% did not have enough data to reach a classification. [Copyright &y& Elsevier]

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species is central in biodiversity conservation, but insufficient resources hamper its long-term growth, updating, and consistency. Models or automated calculations can alleviate those challenges by providing standardised estimates required for assessments, or prioritising species for (re-)assessments. However, while numerous scientific papers have proposed such methods, few have been integrated into assessment practice, highlighting a critical research–implementation gap. We believe this gap can be bridged by fostering communication and collaboration between academic researchers and Red List practitioners, and by developing and maintaining user-friendly platforms to automate application of the methods. We propose that developing methods better encompassing Red List criteria, systems, and drivers is the next priority to support the Red List. The IUCN Red List of Threatened Species plays a central role in monitoring biodiversity and informing conservation actions. To best inform conservation, the Red List must be frequently updated, become more taxonomically and geographically representative, and be consistent within and among taxonomic groups, but this is hampered by limited resources. A variety of models and automated calculations has been proposed in the literature to support Red List assessments, for instance using citizen science or remote-sensing data to predict extinction risk. We highlight a major research–implementation gap in the application of these methods, which could be bridged by providing assessors with easy access to the most relevant tools, hands-on training, and strengthening communication. Further efforts are needed to develop relevant methods to prioritise assessments or better predict extinction risk. [ABSTRACT FROM AUTHOR]

Animal parasites are species rich and ecologically diverse, some with complex life cycles and life histories and consequently many are vulnerable to extinction. While the conservation biology community is becoming cognisant of the plight of threatened parasites, coupled at times with potential host co-extinction, feasible criteria have not been developed to specifically assess their threat risk and methods to conserve them have also received limited attention. Methodologies and criteria are presented here to aid the assessment of the conservation status of threatened parasites in a way consistent with the criteria of the International Union for the Conservation of Nature (IUCN). Such assessments assist in prioritizing conservation efforts, a crucial task given parasites are integral to the functioning and survival of global ecosystems. • Animal parasites are ecologically important and highly vulnerable to extinction. • Available conservation rubrics are poorly suited for assessing animal parasites. • The first assessment framework designed for animal parasites is presented. • Widescale assessments of the conservation status of animal parasites can now occur. [ABSTRACT FROM AUTHOR]

Species differ in their biological susceptibility to extinction, but the set of traits determining susceptibility varies across taxa. It is yet unclear which patterns are common to all taxa, and which are taxon-specific, with consequences to conservation practice. In this study we analysed the generality of trait-based prediction of extinction risk across terrestrial (including freshwater) vertebrates, invertebrates and plants at a global scale. For each group, we selected five representative taxa and within each group we explored whether risk can be related to any of 10 potential predictors. We then synthesized outcomes across taxa using a meta-analytic approach. High habitat specificity was a consistent predictor across vertebrates, invertebrates and plants, being a universal predictor of risk. Slow life-history traits – large relative offspring size, low fecundity, long generation length –, and narrow altitudinal range were also found to be good predictors across most taxa, but their universality needs to be supported with additional data. Poor dispersal ability was a common predictor of extinction risk among invertebrate and plant taxa, but not consistently among vertebrates. The remaining traits (body size, microhabitat verticality, trophic level, and diet breadth) were useful to predict extinction risk but only at lower taxonomical levels. Our study shows that despite the idiosyncrasies among taxa, universal susceptibility to extinction exists and several traits might influence extinction risk for most taxa. Informing conservation prioritization at lower taxonomic scales should however include taxon-specific trait-based predictors of extinction risk. [ABSTRACT FROM AUTHOR]