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Journal: Conservation biology : the journal of the Society for Conservation Biology

41

The IUCN Red List categories and criteria are the most widely used framework for assessing the relative extinction risk of species. The criteria are based on quantitative thresholds relating to the size, trends and structure of species' distributions and populations. However, data on these parameters are sparse and uncertain for many species and unavailable for others, potentially leading to their misclassification, or classification as Data Deficient. Here we propose an approach combining data on land-cover change and species-specific habitat preferences, population abundance and dispersal distance to estimate key parameters (extent of occurrence, maximum area of occupancy, population size and trend, and degree of fragmentation) and hence IUCN Red List categories. We demonstrate the applicability of our approach for non-pelagic birds and terrestrial mammals globally (∼15,000 species), generating predictions fairly consistent with published Red List assessments, but more optimistic overall. We predict 4.2% of species (467 birds and 143 mammals) to be more threatened than currently assessed, and 20.2% of Data Deficient species (10 birds and 114 mammals) to be at risk of extinction. However, incorporating the habitat fragmentation sub-criterion reduced these predictions 1.5-2.3% and 6.4-14.9% (depending on the quantitative definition of fragmentation) of threatened and Data Deficient species respectively, highlighting the need for improved guidance to Red List assessors on applying this aspect of the Red List criteria. Our approach can be used to complement traditional methods of estimating parameters for Red List assessments. Furthermore, it can readily provide an early warning system to identify species potentially warranting changes in their extinction risk category based on periodic updates of land cover information. Given that our method relies on optimistic assumptions about species distribution and abundance, all species predicted to be more at risk than currently evaluated should be prioritized for reassessment. This article is protected by copyright. All rights reserved.

36

Ingestion of marine debris can have lethal and sublethal effects on sea turtles and other wildlife. Although researchers have reported on ingestion of anthropogenic debris by marine turtles and implied incidences of debris ingestion have increased over time, there has not been a global synthesis of the phenomenon since 1985. Thus, we analyzed 37 studies published from 1985 to 2012 that report on data collected from before 1900 through 2011. Specifically, we investigated whether ingestion prevalence has changed over time, what types of debris are most commonly ingested, the geographic distribution of debris ingestion by marine turtles relative to global debris distribution, and which species and life-history stages are most likely to ingest debris. The probability of green (Chelonia mydas) and leatherback turtles (Dermochelys coriacea) ingesting debris increased significantly over time, and plastic was the most commonly ingested debris. Turtles in nearly all regions studied ingest debris, but the probability of ingestion was not related to modeled debris densities. Furthermore, smaller, oceanic-stage turtles were more likely to ingest debris than coastal foragers, whereas carnivorous species were less likely to ingest debris than herbivores or gelatinovores. Our results indicate oceanic leatherback turtles and green turtles are at the greatest risk of both lethal and sublethal effects from ingested marine debris. To reduce this risk, anthropogenic debris must be managed at a global level. Análisis Global de la Ingesta de Residuos Antropogénicos por Tortugas Marinas.

Concepts: Ingestion, Sea turtles, Costa Rica, Kemp's Ridley, Hawksbill turtle, Green turtle, Leatherback turtle, Sea turtle

34

The rise of the Internet as a trade platform has resulted in a shift in the illegal wildlife trade. As a result of increased scrutiny that illegal wildlife trade is receiving, there are concerns that the online trade will move onto the darkweb. In this preliminary study, we provide a baseline of illegal wildlife trade on the darkweb. We downloaded and archived 9,852 items from the darkweb, then searched these based on a list of 121 keywords associated with illegal online wildlife trade, including 30 keywords associated with illegally traded elephant ivory on the surface web. Results were compared with known illegally traded items, specifically cannabis, cocaine and heroin. Of these 121 keywords, only four resulted in hits, of which only one was potentially linked to illegal wildlife trade. This sole case was the sale and discussion of Echinopsis pachanoi (San Pedro cactus), which has hallucinogenic properties. This negligible level of activity on the darkweb, compared to the open and burgeoning trade on the surface web, may indicate a lack of successful enforcement against illegal wildlife trade on the surface web, although other hypothesis are considered and explored. This article is protected by copyright. All rights reserved.

Concepts: Hordenine, All rights reserved, Copyright, Echinopsis lageniformis, Echinopsis peruviana, Psychedelic drug, Echinopsis pachanoi, Echinopsis

31

A key measure of humanity’s global impact is by how much it has increased species extinction rates. Familiar statements are that these are 100-1000 times pre-human or background extinction levels. Estimating recent rates is straightforward, but establishing a background rate for comparison is not. Previous researchers chose an approximate benchmark of 1 extinction per million species per year (E/MSY). We explored disparate lines of evidence that suggest a substantially lower estimate. Fossil data yield direct estimates of extinction rates, but they are temporally coarse, mostly limited to marine hard-bodied taxa, and generally involve genera not species. Based on these data, typical background loss is 0.01 genera per million genera per year. Molecular phylogenies are available for more taxa and ecosystems, but it is debated whether they can be used to estimate separately speciation and extinction rates. We selected data to address known concerns and used them to determine median extinction estimates from statistical distributions of probable values for terrestrial plants and animals. We then created simulations to explore effects of violating model assumptions. Finally, we compiled estimates of diversification-the difference between speciation and extinction rates for different taxa. Median estimates of extinction rates ranged from 0.023 to 0.135 E/MSY. Simulation results suggested over- and under-estimation of extinction from individual phylogenies partially canceled each other out when large sets of phylogenies were analyzed. There was no evidence for recent and widespread pre-human overall declines in diversity. This implies that average extinction rates are less than average diversification rates. Median diversification rates were 0.05-0.2 new species per million species per year. On the basis of these results, we concluded that typical rates of background extinction may be closer to 0.1 E/MSY. Thus, current extinction rates are 1,000 times higher than natural background rates of extinction and future rates are likely to be 10,000 times higher. Estimación de la Tasa Normal de Extinción de Especies.

Concepts: Conservation biology, Approximation, Plant, Normal distribution, Speciation, Extinction, Species, Evolution

30

Large marine protected areas (MPAs), each hundreds of thousands of square kilometers, have been set up by governments around the world over the last decade as part of efforts to reduce ocean biodiversity declines, yet their efficacy is hotly debated. The Chagos Archipelago MPA (640,000 km(2) ) (Indian Ocean) lies at the heart of this debate. We conducted the first satellite tracking of a migratory species, the green turtle (Chelonia mydas), within the MPA and assessed the species' use of protected versus unprotected areas. We developed an approach to estimate length of residence within the MPA that may have utility across migratory taxa including tuna and sharks. We recorded the longest ever published migration for an adult cheloniid turtle (3979 km). Seven of 8 tracked individuals migrated to distant foraging grounds, often ≥1000 km outside the MPA. One turtle traveled to foraging grounds within the MPA. Thus, networks of small MPAs, developed synergistically with larger MPAs, may increase the amount of time migrating species spend within protected areas. The MPA will protect turtles during the breeding season and will protect some turtles on their foraging grounds within the MPA and others during the first part of their long-distance postbreeding oceanic migrations. International cooperation will be needed to develop the network of small MPAs needed to supplement the Chagos Archipelago MPA. Uso de los Patrones de Migración a Larga Distancia de una Especie en Peligro de Extinción para Informar a la Planeación de la Conservación del Área Marina Protegida más Grande.

Concepts: Biodiversity, Turtle soup, Leatherback turtle, Bird migration, Marine Protected Area, Protected area, Coral reef, Human migration

30

Hybridization between endangered species and more common species is a significant problem in conservation biology because it may result in extinction or loss of adaptation. The historical reduction in abundance and geographic distribution of the American plains bison (Bison bison bison) and their recovery over the last 125 years is well documented. However, introgression from domestic cattle (Bos taurus) into the few remaining bison populations that existed in the late 1800s has now been identified in many modern bison herds. We examined the phenotypic effect of this ancestry by comparing weight and height of bison with cattle or bison mitochondrial DNA (mtDNA) from Santa Catalina Island, California (U.S.A.), a nutritionally stressful environment for bison, and of a group of age-matched feedlot bison males in Montana, a nutritionally rich environment. The environmental and nutritional differences between these 2 bison populations were very different and demonstrated the phenotypic effect of domestic cattle mtDNA in bison over a broad range of conditions. For example, the average weight of feedlot males that were 2 years of age was 2.54 times greater than that of males from Santa Catalina Island. In both environments, bison with cattle mtDNA had lower weight compared with bison with bison mtDNA, and on Santa Catalina Island, the height of bison with cattle mtDNA was lower than the height of bison with bison mtDNA. These data support the hypothesis that body size is smaller and height is lower in bison with domestic cattle mtDNA and that genomic integrity is important for the conservation of the American plains bison. Efectos Fenotípicos del ADN Mitocondrial de Ganado en el Bisonte Americano.

Concepts: Beef, Cattle, Bos, Gaur, Bovinae, Extinction, American Bison, Bison

29

Indian Himalayan basins are earmarked for widespread dam building, but aggregate effects of these dams on terrestrial ecosystems are unknown. We mapped distribution of 292 dams (under construction and proposed) and projected effects of these dams on terrestrial ecosystems under different scenarios of land-cover loss. We analyzed land-cover data of the Himalayan valleys, where dams are located. We estimated dam density on fifth- through seventh-order rivers and compared these estimates with current global figures. We used a species-area relation model (SAR) to predict short- and long-term species extinctions driven by deforestation. We used scatter plots and correlation studies to analyze distribution patterns of species and dams and to reveal potential overlap between species-rich areas and dam sites. We investigated effects of disturbance on community structure of undisturbed forests. Nearly 90% of Indian Himalayan valleys would be affected by dam building and 27% of these dams would affect dense forests. Our model projected that 54,117 ha of forests would be submerged and 114,361 ha would be damaged by dam-related activities. A dam density of 0.3247/1000 km(2) would be nearly 62 times greater than current average global figures; the average of 1 dam for every 32 km of river channel would be 1.5 times higher than figures reported for U.S. rivers. Our results show that most dams would be located in species-rich areas of the Himalaya. The SAR model projected that by 2025, deforestation due to dam building would likely result in extinction of 22 angiosperm and 7 vertebrate taxa. Disturbance due to dam building would likely reduce tree species richness by 35%, tree density by 42%, and tree basal cover by 30% in dense forests. These results, combined with relatively weak national environmental impact assessment and implementation, point toward significant loss of species if all proposed dams in the Indian Himalaya are constructed. Efectos Potenciales del Desarrollo Hidroeléctrico Actual y Propuesto sobre la Diversidad Biológica Terrestre en el Himalaya Hindú

Concepts: Impact assessment, Hydroelectricity, Himalayas, River, Extinction, Environmental impact assessment, Biodiversity, Dam

28

That at least some aspects of nature possess intrinsic value is considered by some an axiom of conservation. Others consider nature’s intrinsic value superfluous or anathema. This range of views among mainstream conservation professionals potentially threatens the foundation of conservation. One challenge in resolving this disparity is that disparaging portrayals of nature’s intrinsic value appear rooted in misconceptions and unfounded presumptions about what it means to acknowledge nature’s intrinsic value. That acknowledgment has been characterized as vacuous, misanthropic, of little practical consequence to conservation, adequately accommodated by economic valuation, and not widely accepted in society. We reviewed the philosophical basis for nature’s intrinsic value and the implications for acknowledging that value. Our analysis is rooted to the notion that when something possesses intrinsic value it deserves to be treated with respect for what it is, with concern for its welfare or in a just manner. From this basis, one can only conclude that nature’s intrinsic value is not a vacuous concept or adequately accommodated by economic valuation. Acknowledging nature’s intrinsic value is not misanthropic because concern for nature’s welfare (aside from its influence on human welfare) does not in any way preclude also being concerned for human welfare. The practical import of acknowledging nature’s intrinsic value rises from recognizing all the objects of conservation concern (e.g., many endangered species) that offer little benefit to human welfare. Sociological and cultural evidence indicates the belief that at least some elements of nature possess intrinsic value is widespread in society. Our reasoning suggests the appropriateness of rejecting the assertion that nature’s intrinsic value is anathema to conservation and accepting its role as an axiom. Evaluar si el Valor Intrínseco de la Naturaleza es un Axioma o un Anatema para la Conservación.

Concepts: Morality, Intrinsic value, Logic, Ethics, Value theory, Endangered species, Sociology, Meaning of life

28

Conservation of sea snakes is virtually nonexistent in Asia, and its role in human-snake interactions in terms of catch, trade, and snakebites as an occupational hazard is mostly unexplored. We collected data on sea snake landings from the Gulf of Thailand, a hotspot for sea snake harvest by squid fishers operating out of the ports of Song Doc and Khanh Hoi, Ca Mau Province, Vietnam. The data were collected during documentation of the steps of the trading process and through interviewers with participants in the trade. Squid vessels return to ports once per lunar synodic cycle and fishers sell snakes to merchants who sort, package, and ship the snakes to various destinations in Vietnam and China for human consumption and as a source of traditional remedies. Annually, 82 t, roughly equal to 225,500 individuals, of live sea snakes are brought to ports. To our knowledge, this rate of harvest constitutes one of the largest venomous snake and marine reptile harvest activities in the world today. Lapemis curtus and Hydrophis cyanocinctus constituted about 85% of the snake biomass, and Acalyptophis peronii, Aipysurus eydouxii, Hydrophis atriceps, H. belcheri, H. lamberti, and H. ornatus made up the remainder. Our results establish a quantitative baseline for characteristics of catch, trade, and uses of sea snakes. Other key observations include the timing of the trade to the lunar cycle, a decline of sea snakes harvested over the study period (approximately 30% decline in mass over 4 years), and the treatment of sea snake bites with rhinoceros horn. Emerging markets in Southeast Asia drive the harvest of venomous sea snakes in the Gulf of Thailand and sea snake bites present a potentially lethal occupational hazard. We call for implementation of monitoring programs to further address the conservation implications of this large-scale marine reptile exploitation. Cosecha de Serpientes Marinas en el Golfo de Tailandia.

Concepts: Viperidae, Hydrophis, Vietnam, Venomous snake, Elapidae, Sea snakes, Sea snake, Snake

28

It is widely accepted that the main driver of the observed decline in biological diversity is increasing human pressure on Earth’s ecosystems. However, the spatial patterns of change in human pressure and their relation to conservation efforts are less well known. We developed a spatially and temporally explicit map of global change in human pressure over 2 decades between 1990 and 2010 at a resolution of 10 km(2) . We evaluated 22 spatial data sets representing different components of human pressure and used them to compile a temporal human pressure index (THPI) based on 3 data sets: human population density, land transformation, and electrical power infrastructure. We investigated how the THPI within protected areas was correlated to International Union for Conservation of Nature (IUCN) management categories and the human development index (HDI) and how the THPI was correlated to cumulative pressure on the basis of the original human footprint index. Since the early 1990s, human pressure increased 64% of the terrestrial areas; the largest increases were in Southeast Asia. Protected areas also exhibited overall increases in human pressure, the degree of which varied with location and IUCN management category. Only wilderness areas and natural monuments (management categories Ib and III) exhibited decreases in pressure. Protected areas not assigned any category exhibited the greatest increases. High HDI values correlated with greater reductions in pressure across protected areas, while increasing age of the protected area correlated with increases in pressure. Our analysis is an initial step toward mapping changes in human pressure on the natural world over time. That only 3 data sets could be included in our spatio-temporal global pressure map highlights the challenge to measuring pressure changes over time. Mapeo del Cambio en la Presión Humana Global en Tierra y Dentro de Áreas Protegidas.

Concepts: American Human Development Report, 1990s, Developed country, Population density, Natural environment, Category theory, Human Development Index, Nature