In response to growing demand for ecosystem‐level risk assessment in biodiversity conservation, and rapid proliferation of locally tailored protocols, the IUCN recently endorsed new Red List criteria ...as a global standard for ecosystem risk assessment. Four qualities were sought in the design of the IUCN criteria: generality; precision; realism; and simplicity. Drawing from extensive global consultation, we explore trade‐offs among these qualities when dealing with key challenges, including ecosystem classification, measuring ecosystem dynamics, degradation and collapse, and setting decision thresholds to delimit ordinal categories of threat. Experience from countries with national lists of threatened ecosystems demonstrates well‐balanced trade‐offs in current and potential applications of Red Lists of Ecosystems in legislation, policy, environmental management and education. The IUCN Red List of Ecosystems should be judged by whether it achieves conservation ends and improves natural resource management, whether its limitations are outweighed by its benefits, and whether it performs better than alternative methods. Future development of the Red List of Ecosystems will benefit from the history of the Red List of Threatened Species which was trialed and adjusted iteratively over 50 years from rudimentary beginnings. We anticipate the Red List of Ecosystems will promote policy focus on conservation outcomes in situ across whole landscapes and seascapes.
An understanding of risks to biodiversity is needed for planning action to slow current rates of decline and secure ecosystem services for future human use. Although the IUCN Red List criteria ...provide an effective assessment protocol for species, a standard global assessment of risks to higher levels of biodiversity is currently limited. In 2008, IUCN initiated development of risk assessment criteria to support a global Red List of ecosystems. We present a new conceptual model for ecosystem risk assessment founded on a synthesis of relevant ecological theories. To support the model, we review key elements of ecosystem definition and introduce the concept of ecosystem collapse, an analogue of species extinction. The model identifies four distributional and functional symptoms of ecosystem risk as a basis for assessment criteria: A) rates of decline in ecosystem distribution; B) restricted distributions with continuing declines or threats; C) rates of environmental (abiotic) degradation; and D) rates of disruption to biotic processes. A fifth criterion, E) quantitative estimates of the risk of ecosystem collapse, enables integrated assessment of multiple processes and provides a conceptual anchor for the other criteria. We present the theoretical rationale for the construction and interpretation of each criterion. The assessment protocol and threat categories mirror those of the IUCN Red List of species. A trial of the protocol on terrestrial, subterranean, freshwater and marine ecosystems from around the world shows that its concepts are workable and its outcomes are robust, that required data are available, and that results are consistent with assessments carried out by local experts and authorities. The new protocol provides a consistent, practical and theoretically grounded framework for establishing a systematic Red List of the world's ecosystems. This will complement the Red List of species and strengthen global capacity to report on and monitor the status of biodiversity.
The newly developed IUCN Red List of Ecosystems is part of a growing toolbox for assessing risks to biodiversity, which addresses ecosystems and their functioning. The Red List of Ecosystems standard ...allows systematic assessment of all freshwater, marine, terrestrial and subterranean ecosystem types in terms of their global risk of collapse. In addition, the Red List of Ecosystems categories and criteria provide a technical base for assessments of ecosystem status at the regional, national, or subnational level. While the Red List of Ecosystems criteria were designed to be widely applicable by scientists and practitioners, guidelines are needed to ensure they are implemented in a standardized manner to reduce epistemic uncertainties and allow robust comparisons among ecosystems and over time. We review the intended application of the Red List of Ecosystems assessment process, summarize 'best-practice' methods for ecosystem assessments and outline approaches to ensure operational rigour of assessments. The Red List of Ecosystems will inform priority setting for ecosystem types worldwide, and strengthen capacity to report on progress towards the Aichi Targets of the Convention on Biological Diversity. When integrated with other IUCN knowledge products, such as the World Database of Protected Areas/Protected Planet, Key Biodiversity Areas and the IUCN Red List of Threatened Species, the Red List of Ecosystems will contribute to providing the most complete global measure of the status of biodiversity yet achieved.
Although most often considered independently, subsistence hunting, domestic trade, and international trade as components of illegal wildlife use (IWU) may be spatially correlated. Understanding how ...and where subsistence and commercial uses may co-occur has important implications for the design and implementation of effective conservation actions. We analyzed patterns in the joint geographical distribution of illegal commercial and subsistence use of multiple wildlife species in Venezuela and evaluated whether available data were sufficient to provide accurate estimates of the magnitude, scope, and detectability of IWU. We compiled records of illegal subsistence hunting and trade from several sources and fitted a random-forest classification model to predict the spatial distribution oflWUs. From 1969 to 2014, 404 species and 8,340,921 specimens were involved in IWU, for a mean extraction rate of 185,354 individuals/year. Birds were the most speciose group involved (248 spp.), but reptiles had the highest extraction rates (126,414 individuals/year vs. 3,133 individuals/year for birds). Eighty-eight percent of international trade records spatially overlapped with domestic trade, especially in the north and along the coast but also in western inland areas. The distribution of domestic trade was broadly distributed along roads, suggesting that domestic trade does not depend on large markets in cities. Seventeen percent of domestic trade records overlapped with subsistence hunting, but the spatial distribution of this overlap covered a much larger area than between commercial uses. Domestic trade seems to respond to demand from rural more than urban communities. Our approach will be useful for understanding how IWU works at national scales in other parts of the world. Aunque muchas veces son considerados independientemente, la caza de subsistencia y el comercio doméstico e internacional como componentes del uso ilegal de vida silvestre (UIVS) pueden estar correlacionados espacialmente. Entender cómo y dónde los usos comerciales y de subsistencia pueden co-ocurrir tiene implicaciones importantes para el diseño y la implementación de acciones efectivas de conservación. Analizamos los patrones en la distribución geográfica conjunta del uso ilegal comercial o por subsistencia de múltiples especies de vida silvestre en Venezuela y evaluamos si los datos disponibles eran suficientes para proporcionar estimaciones correctas de la magnitud, el alcance y la detectabilidad del UIVS. Compilamos los registros del comercio y la caza de subsistencia ilegales de varias fuentes y acoplamos un modelo de bosques aleatorios para predecir la distribución espacial del UIVS. De 1969 a 2014, 404 especies y 8,340,921 especímenes estuvieron involucrados en UIVS, para una tasa de extracción media de 185,354 individuos/año. Las aves fueron el grupo involucrado más rico en especies (248 spp.), pero los reptiles tuvieron las tasas de extracción más altas (126, 414 individuos/año contra 3,133 individuos/año para las aves). El 88% de los registros del comercio internacional se solapó espacialmente con el comercio doméstico, especialmente en el norte y a lo largo de la costa, pero también en las áreas occidentales tierra adentro. La extensión del comercio doméstico estuvo distribuida ampliamente a lo largo de las carreteras, lo que sugiere que el comercio doméstico no depende de un gran mercado en las ciudades. El 17% de los registros de comercio doméstico se solapó con la caza por subsistencia, pero la distribución espacial de este solapamiento cubrió un área mucho mayor que entre los usos comerciales. El comercio doméstico parece responder a la demanda rural más que a la demanda de las comunidades urbanas. Nuestra estrategia será útil para entender cómo funcionan los UIVS a escala nacional en otras partes del mundo.
Fisheries, either directed or via bycatch, are a major cause of decline in global populations of marine turtles. Although artisanal fisheries are often seen as lower-impact than industrial fisheries, ...they may be among the most serious threats to green turtles. Between 2005 and 2008, to better understand the impacts of such fisheries in the High Extraction Zone of the Gulf of Venezuela (HEZ-GV), an important feeding habitat for green turtles, we interviewed fishers, observed fishing activities directly, and counted, measured, and marked discarded turtle carapaces at fishing ports and traditional markets. From these, we estimated that at least 3,402 ± 247 turtles/year were extracted with artisanal nets, suggesting that the HEZ-GV artisanal turtle fishery may have been among the most active in the Caribbean at the time, with a CPUE of 0.04 turtles/km-net*hour ±0.014. However, capture was not selective, confirming prior anecdotal information suggesting that this fishery supplies mainly subsistence and not commercial use. Harvested turtles consisted mainly of juveniles (64%, CCLmin = 55.7 cm ± SE 0.9), and subadults (35%, CCLmin = 78.9 cm ± 0.6 cm), with very few adults (1%, CCLmin = 98 cm ± 0.6 cm). Our findings highlight the need for continued monitoring of the artisanal turtle fishery in the HEZ-GV, particularly given the possibility of increased reliance on aquatic bushmeat sources in Venezuela's present socio-economic crisis. More broadly, they also indicate that scientifically based catch guidelines for marine turtles may be just as important in artisanal as in commercial fisheries, to ensure sustainability and mitigate harvest impacts.
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•We estimated that 3,402 ± 247 turtles/year were extracted in the study area. with a CPUE of 0.04 turtles/km-net*hour ± 0.014.•Harvested green turtles were mostly immature-(99%). with few adults (1%).•Our results highlight the need for management and monitoring of the artisanal turtle fishery in the HEZ-GV.
Species distribution models (SDM) can be valuable for identifying key habitats for conservation management of threatened taxa, but anthropogenic habitat change can undermine SDM accuracy. We used ...data for the Red Siskin (Spinus cucullatus), a critically endangered bird and ground truthing to examine anthropogenic habitat change as a source of SDM inaccuracy. We aimed to estimate: (1) the Red Siskin's historic distribution in Venezuela; (2) the portion of this historic distribution lost to vegetation degradation; and (3) the location of key habitats or areas with both, a high probability of historic occurrence and a low probability of vegetation degradation. We ground‐truthed 191 locations and used expert opinion as well as landscape characteristics to classify species' habitat suitability as excellent, good, acceptable, or poor. We fit a Random Forest model (RF) and Enhanced Vegetation Index (EVI) time series to evaluate the accuracy and precision of the expert categorization of habitat suitability. We estimated the probability of historic occurrence by fitting a MaxLike model using 88 presence records (1960–2013) and data on forest cover and aridity index. Of the entire study area, 23% (20,696 km2) had a historic probability of Red Siskin occurrence over 0.743. Furthermore, 85% of ground‐truthed locations had substantial reductions in mean EVI, resulting in key habitats totaling just 976 km2, in small blocks in the western and central regions. Decline in Area of Occupancy over 15 years was between 40% and 95%, corresponding to an extinction risk category between Vulnerable and Critically Endangered. Relating key habitats with other landscape features revealed significant risks and opportunities for proposed conservation interventions, including the fact that ongoing vegetation degradation could limit the establishment of reintroduced populations in eastern areas, while the conservation of remaining key habitats on private lands could be improved with biodiversity‐friendly agri‐ and silviculture programs.
We present a useful approach combining species distribution models and vegetation time series to improve the identification of key habitats for conservation when information about habitat use and species ecology is limited. We demonstrate the approach using data on Red Siskin (Spinus cucullatus), a low abundance and critically endangered bird in Venezuela. Ongoing vegetation degradation could limit the establishment of reintroduced populations in eastern areas.
The yellow-shouldered parrot (
Amazona barbadensis) is listed in Venezuela as Endangered and internationally as Vulnerable, primarily due to poaching for the illegal pet trade. Various interventions ...have been implemented to reduce poaching (increasing the population from 700 in 1989 to 1600 in 2009), but poaching pressure is still high, and is ever-changing, requiring an evolving response. Between 2000 and 2003, our only intervention was environmental education in schools: in the short term, unsurprisingly, it had no impact on poaching, which reached 100% of nestlings in monitored nests. From 2004 onwards, we implemented a set of new field interventions. In 2004, 24
h field surveillance decreased poaching to 56%. In 2005, the addition of foster nests and a pilot test of “assisted breeding” brought the figure down to 18%. In 2006, assisted breeding was expanded, achieving 0% poaching. In 2007, poachers raided our “secure” site, and took 34 nestlings, bringing poaching up to 60%. A pilot study of artificial nests offered promising results. In 2008 and 2009, the addition of patrolling by local police reduced poaching to 16% and 1%, respectively. During 2004–2009, nestling poaching averaged 25%. Ensuring parrot recruitment in the future will require a combination of the strategies employed to date; in the short term, expanding the use of artificial nests to increase availability of nesting sites in easily-patrolled areas has the most potential to build on past successes.
Long-term demographic data are valuable for assessing the effect of anthropogenic impacts on endangered species and evaluating recovery programs. Using a 2-state open robust design model, we analyzed ...mark-recapture data from green turtles Chelonia mydas sighted between 1979 and 2009 on Aves Island, Venezuela, a rookery heavily impacted by human activities before it was declared a wildlife refuge in 1972. Based on the encounter histories of 7689 nesting females, we estimated the abundance, annual survival, and remigration intervals for this population. Female survival varied from 0.14-0.91, with a mean of 0.79, which is low compared to survival of other populations from the Caribbean (mean = 0.84) and Australia (mean = 0.95), even though we partially corrected for tag loss, which is known to negatively bias survival estimates. This supports prior suggestions that Caribbean populations in general, and the Aves Island population in particular, may be more strongly impacted than populations elsewhere. It is likely that nesters from this rookery are extracted while foraging in remote feeding grounds where hunting still occurs. Despite its relatively low survival, the nesting population at Aves Island increased during the past 30 years from approx. 500 to >1000 nesting females in 2009. Thus, this population, like others in the Caribbean and the Atlantic, seems to be slowly recovering following protective management. Although these findings support the importance of long-term conservation programs aimed at protecting nesting grounds, they also highlight the need to extend management actions to foraging grounds where human activities may still impact green turtle populations.
Aim: To test a method for rapidly and reliably collecting species distribution and abundance data over large tropical areas known as Neotropical Biodiversity Mapping Initiative (NeoMaps), explicitly ...seeking to improve cost- and time-efficiencies over existing methods (i.e. museum collections, literature), while strengthening local capacity for data collection. Location: Venezuela. Methods: We placed a grid over Venezuela (0.5 × 0.5 degree cells) and applied a stratified sampling design to select a minimum set of 25 cells spanning environmental and biogeographical variation. We implemented standardized field sampling protocols for birds, butterflies and dung beetles, along transects on environmental gradients ('gradsects'). We compared species richness estimates from our field surveys at national, bioregional and cell scales to those calculated from data compiled from museum collections and the literature. We estimated the variance in richness, composition, relative abundance and diversity between gradsects that could be explained by environmental and biogeographical variables. We also estimated total survey effort and cost. Results: In one field season, we covered 8% of the country and recorded 66% of all known Venezuelan dung beetles, 52% of Pierid butterflies and 37% of birds. Environmental variables explained 27—60% of variation in richness for all groups and 13—43% of variation in abundance and diversity in dung beetles and birds. Bioregional and environmental variables explained 43—58% of the variation in the dissimilarity matrix between transects for all groups. Main conclusions: NeoMaps provides reliable estimates of richness, composition and relative abundance, required for rigorous monitoring and spatial prediction. NeoMaps requires a substantial investment, but is highly efficient, achieving survey goals for each group with 1-month fieldwork and about US$ 1—8 per km 2 . Future work should focus on other advantages of this type of survey, including the ability to monitor the changes in relative abundance and turnover in species composition, and thus overall diversity patterns.
Captive breeding and reintroduction can be effective conservation tools, but the origin of founders for such programs is key for success. The red siskin Spinus cucullatus, a bird from northern South ...America, is Critically Endangered in Venezuela due to decades of trapping for the illegal wildlife trade. As a result, many red siskins are held in captivity worldwide, but several potential problems with captive birds make considering founders from the wild more desirable. A recently discovered population of red siskins in Guyana presents such an opportunity, but, due to its disjunct distribution from the main range, the possibility of genetic differentiation is a concern. We used a variety of standard and novel analyses of amplified fragment length polymorphism (AFLP) and mitochondrial (mtDNA) markers to evaluate genetic divergence of the Guyana (GU) population, using 5 individuals from GU and 13 captive birds of presumed Venezuelan (‘VE’) origin. All analyses of nuclear loci revealed 2 clusters separating GU from ‘VE’ individuals, with FST values varying from 0.15 to 0.24, depending on assumptions about individual relatedness. Furthermore, all 5 GU birds shared an mtDNA haplotype that differed by 2 or more substitutions (0.11%) from the 3 ‘VE’ haplotypes. The GU population thus appears to be differentiated from the ‘VE’ population in both nuclear and mtDNA. While further genetic evidence is needed, these data suggest that the GU population is not an optimal source of founders for recovery efforts in Venezuela, and should be treated as a separate elemental conservation unit until additional data are available.
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