AIM: To apply mathematical models to the task of predicting extinction risk for species currently listed as ‘Data Deficient’ (DD) by the International Union for the Conservation of Nature (IUCN). We ...demonstrate this approach by applying it globally to amphibians, the vertebrate group recognized as being most extinction threatened and having the largest proportion of DD species. We combine model predictions with current extinction risk knowledge to highlight regions of greatest disparity between known and predicted risk, where potential species extinctions may be overlooked. LOCATION: Global. METHODS: Using global amphibian distribution data obtained from the IUCN and species trait data, we apply machine learning randomForest models to predict extinction risk of DD species from life history traits, environmental variables and habitat loss. These models are trained using data for species that have been assigned to an extinction risk category (other than DD) by the IUCN. We then combine predictions for DD species with IUCN assessment data in a GIS framework to highlight anomalies between current knowledge of amphibian extinction risk and our model predictions. RESULTS: We show that DD amphibian species are likely to be more threatened with extinction than their fully assessed counterparts. Regions in South America, central Africa and North Asia are particularly at risk due to lack of species knowledge and higher extinction risk than currently recognized. MAIN CONCLUSIONS: Application of predictive models ranking regions and species most in need of primary research allows prioritization of limited resources in an informed context, minimizing risk of unnoticed species' extinction.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NMLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Tropical forests continue to be felled and fragmented around the world. A key question is how rapidly species disappear from forest fragments and how quickly humans must restore forest connectivity ...to minimize extinctions. We surveyed small mammals on forest islands in Chiew Larn Reservoir in Thailand 5 to 7 and 25 to 26 years after isolation and observed the near-total loss of native small mammals within 5 years from < 10-hectare (ha) fragments and within 25 years from 10- to 56-ha fragments. Based on our results, we developed an island biogeographic model and estimated mean extinction half-life (50% of resident species disappearing) to be 13.9 years. These catastrophic extinctions were probably partly driven by an invasive rat species; such biotic invasions are becoming increasingly common in human-modified landscapes. Our results are thus particularly relevant to other fragmented forest landscapes and suggest that small fragments are potentially even more vulnerable to biodiversity loss than previously thought.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Most ecological processes now show responses to anthropogenic climate change. In terrestrial, freshwater, and marine ecosystems, species are changing genetically, physiologically, morphologically, ...and phenologically and are shifting their distributions, which affects food webs and results in new interactions. Disruptions scale from the gene to the ecosystem and have documented consequences for people, including unpredictable fisheries and crop yields, loss of genetic diversity in wild crop varieties, and increasing impacts of pests and diseases. In addition to the more easily observed changes, such as shifts in flowering phenology, we argue that many hidden dynamics, such as genetic changes, are also taking place. Understanding shifts in ecological processes can guide human adaptation strategies. In addition to reducing greenhouse gases, climate action and policy must therefore focus equally on strategies that safeguard biodiversity and ecosystems.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
The complex history of Southeast Asian islands has long been of interest to biogeographers. Dispersal and vicariance events in the Pleistocene have received the most attention, though recent studies ...suggest a potentially more ancient history to components of the terrestrial fauna. Among this fauna is the enigmatic archaeobatrachian frog genus Barbourula, which only occurs on the islands of Borneo and Palawan. We utilize this lineage to gain unique insight into the temporal history of lineage diversification in Southeast Asian islands.
Using mitochondrial and nuclear genetic data, multiple fossil calibration points, and likelihood and Bayesian methods, we estimate phylogenetic relationships and divergence times for Barbourula. We determine the sensitivity of focal divergence times to specific calibration points by jackknife approach in which each calibration point is excluded from analysis. We find that relevant divergence time estimates are robust to the exclusion of specific calibration points. Barbourula is recovered as a monophyletic lineage nested within a monophyletic Costata. Barbourula diverged from its sister taxon Bombina in the Paleogene and the two species of Barbourula diverged in the Late Miocene.
The divergences within Barbourula and between it and Bombina are surprisingly old and represent the oldest estimates for a cladogenetic event resulting in living taxa endemic to Southeast Asian islands. Moreover, these divergence time estimates are consistent with a new biogeographic scenario: the Palawan Ark Hypothesis. We suggest that components of Palawan's terrestrial fauna might have "rafted" on emergent portions of the North Palawan Block during its migration from the Asian mainland to its present-day position near Borneo. Further, dispersal from Palawan to Borneo (rather than Borneo to Palawan) may explain the current day disjunct distribution of this ancient lineage.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The taxonomic challenge posed by cryptic species (two or more distinct species classified as a single species) has been recognized for nearly 300 years, but the advent of relatively inexpensive and ...rapid DNA sequencing has given biologists a new tool for detecting and differentiating morphologically similar species. Here, we synthesize the literature on cryptic and sibling species and discuss trends in their discovery. However, a lack of systematic studies leaves many questions open, such as whether cryptic species are more common in particular habitats, latitudes or taxonomic groups. The discovery of cryptic species is likely to be non-random with regard to taxon and biome and, hence, could have profound implications for evolutionary theory, biogeography and conservation planning.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
6.
Climate change vulnerability assessment of species Foden, Wendy B.; Young, Bruce E.; Akçakaya, H. Resit ...
Wiley interdisciplinary reviews. Climate change,
January/February 2019, Volume:
10, Issue:
1
Journal Article
Peer reviewed
Open access
Assessing species' vulnerability to climate change is a prerequisite for developing effective strategies to conserve them. The last three decades have seen exponential growth in the number of studies ...evaluating how, how much, why, when, and where species will be impacted by climate change. We provide an overview of the rapidly developing field of climate change vulnerability assessment (CCVA) and describe key concepts, terms, steps and considerations. We stress the importance of identifying the full range of pressures, impacts and their associated mechanisms that species face and using this as a basis for selecting the appropriate assessment approaches for quantifying vulnerability. We outline four CCVA assessment approaches, namely trait‐based, correlative, mechanistic and combined approaches and discuss their use. Since any assessment can deliver unreliable or even misleading results when incorrect data and parameters are applied, we discuss finding, selecting, and applying input data and provide examples of open‐access resources. Because rare, small‐range, and declining‐range species are often of particular conservation concern while also posing significant challenges for CCVA, we describe alternative ways to assess them. We also describe how CCVAs can be used to inform IUCN Red List assessments of extinction risk. Finally, we suggest future directions in this field and propose areas where research efforts may be particularly valuable.
This article is categorized under:
Climate, Ecology, and Conservation > Extinction Risk
Assessing species' vulnerability to climate change is becoming a prerequisite for conservation planning, but choosing approaches, methods and data can be challenging. Key to informing such choices is consideration of the full range of climate change pressures and their likely mechanisms of impact on individuals, subpopulations and species. Navigate a sound path through do's and don'ts, and explore resources and future perspectives in this exciting field.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We describe a new species of very small (male body length 22.0–22.8 mm), green treefrog in the pelodryadid genus Litoria Tschudi from lowland rainforest on the southern margin of Papua New Guinea's ...central cordillera. The new species is morphologically most similar to Litoria leucova, a small green treefrog known only from the north-flowing Sepik River catchment in western Papua New Guinea. It differs from that species by having longer limbs (TL/SVL 0.56–0.60 vs. 0.53–0.55), a poorly defined (vs. prominent) tympanum, in having a distinct lemon yellow mid-lateral line, and in its unique advertisement call comprising a slowly repeated series of short clicks followed by a discrete group of pulses produced rapidly but with highly variable inter-pulse intervals. Although genetic data are not available, the new species' association with a fast-flowing rocky stream suggests that its relationships may lie with other torrent-dwelling Litoria species.
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FFLJ, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UL, UM, UPUK
The arboreal frog, Chiromantis hansenae (Family: Rhacophoridae), is one of only a handful of South‐East Asian amphibian species reported with parental care. We present the first systematic ...observational and experimental study confirming offspring benefits as a result of this care, which has a number of unusual life‐history characteristics. Eggs are unusually small, breeding takes place in large pools, and females attend the eggs. Field observations and an adult removal experiment demonstrated a critical contribution of egg attendance to offspring survivorship. Harsh environmental conditions for offspring appeared to be the prime mover of parental care in this species, with desiccation as the main source of mortality when attending adults are absent. Results confirm females to be the caregivers, making C. hansenae a rare case of maternal egg attendance in a non‐directly developing anuran.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Southeast Asia is a region of conservation concern due to heavy losses of its native habitats. In this overview, we highlight the conservation importance of Southeast Asia by comparing its degree of ...species endemism and endangerment, and its rate of deforestation with other tropical regions (i.e., Meso-America, South America, and Sub-Saharan Africa). Southeast Asia contains the highest mean proportion of country-endemic bird (9%) and mammal species (11%). This region also has the highest proportion of threatened vascular plant, reptile, bird, and mammal species. Furthermore, not only is Southeast Asia's annual deforestation rate the highest in the tropics, but it has also increased between the periods 1990-2000 and 2000-2005. This could result in projected losses of 13-85% of biodiversity in the region by 2100. Secondary habitat restoration, at least in certain countries, would allow for some amelioration of biodiversity loss and thus potentially lower the currently predicted extinction rates. Nonetheless, urgent conservation actions are needed. Conservation initiatives should include public education, sustaining livelihoods, and ways to enhance the sustainability of agriculture and increase the capacity of conservation institutions. Furthermore, these actions should be country-specific and not ignore areas heavily populated by humans, as they can also harbour high numbers of threatened species. We urge that cooperative conservation initiatives be undertaken and support (e.g., capacity-building) be given by more developed countries in the region and beyond.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The loss of biodiversity due to overexploitation is well known, but a review and regulation of species used in the frogs’ legs trade has yet to be accomplished. This problem relates to supply (the ...capture and trade of wild populations) and demand (the main consumer being the EU). The EU’s responsibility should not be ignored, since unsustainable imports of certain species drives population decline and increases risk of extinction. For most organisms, including frog species in the frogs’ legs trade, commercial international trade remains unregulated, includes species in extinction-threat categories on the IUCN Red List, and is not economically sustainable. With a tradition of frogs’ legs consumption anchored in western EU countries, demand for many species from the principal supplying countries (Indonesia, Vietnam, Turkey, Albania) has resulted in the overexploitation of the regional populations of many species. Unfortunately, legal trade takes place in the midst of numerous uncertainties, including unresolved taxonomic status for many frogs, no database or regulation of trade-relevant species, unknown population status, and no health standards for the animals involved in the trade. In addition, regional overharvest may increase the use of pesticides, there is uncertain but likely spread of disease along the trade chain, and certification schemes for frog farming operations are both not standardised and can lead to exotic invasive species escaping into naïve ecosystems. Mechanisms to help make the international trade in frogs’ legs sustainable are essential, and require international agreement and targeted efforts, ideally financed by the trade sector itself.
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