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The World Wide Fund for Nature is an international non-governmental organization founded on April 29, 1961, and is working on issues regarding the conservation, research and restoration of the environment. It was formerly named the World Wildlife Fund, which remains its official name in Canada and the United States. It is the world's largest conservation organization with over 5 million supporters worldwide, working in more than 100 countries, supporting around 1,300 conservation and environmental projects. WWF is a foundation, in 2010 deriving 57% of funding from individuals and bequests, 17% from government sources and 11% from corporations.The group's mission is "to stop the degradation of the planet’s natural environment and to build a future in which humans live in harmony with nature." Currently, much of its work focuses on the conservation of three biomes that contain most of the world's biodiversity: oceans and coasts, forests, and freshwater ecosystems. Among other issues, it is also concerned with endangered species, pollution and climate change. Wikipedia.

Tobler M.W.,Institute for Conservation Research | Powell G.V.N.,World Wildlife Fund
Biological Conservation | Year: 2013

Camera traps have become the main method for estimating jaguar (Panthera onca) densities. Over 74 studies have been carried out throughout the species range following standard design recommendations. We reviewed the study designs used by these studies and the results obtained. Using simulated data we evaluated the performance of different statistical methods for estimating density from camera trap data including the closed-population capture-recapture models Mo and Mh with a buffer of 1/2 and the full mean maximum distance moved (MMDM) and spatially explicit capture-recapture (SECR) models under different study designs and scenarios. We found that for the studies reviewed density estimates were negatively correlated with camera polygon size and MMDM estimates were positively correlated. The simulations showed that for camera polygons that were smaller than approximately one home range density estimates for all methods had a positive bias. For large polygons the Mh MMDM and SECR model produced the most accurate results and elongated polygons can improve estimates with the SECR model. When encounter rates and home range sizes varied by sex, estimates had a negative bias for models that did not include sex as a covariate. Based on the simulations we concluded that the majority of jaguar camera trap studies did not meet the requirements necessary to produce unbiased density estimates and likely overestimated true densities. We make clear recommendations for future study designs with respect to camera layout, number of cameras, study length, and camera placement. Our findings directly apply to camera trap studies of other large carnivores. © 2012 Elsevier Ltd. Source

Davis A.K.,University of Georgia | Rendon-Salinas E.,World Wildlife Fund
Biology Letters | Year: 2010

Every autumn the entire eastern North American population of monarch butterflies (Danaus plexippus) undergoes a spectacular migration to overwintering sites in the mountains of central Mexico, where they form massive clusters and can number in the millions. Since their discovery, these sites have been extensively studied, and in many of these studies, monarchs were captured and sexes recorded. In a recent effort to compile the sex ratio data from these published records, a surprising trend was found, which appears to show a gradual decline in proportion of females over time. Sex ratio data from 14 collections of monarchs, all spanning 30 years and totaling 69 113 individuals, showed a significant negative correlation between proportion of females and year (r = -0.69, p = 0.007). Between 1976 and 1985, 53 per cent of overwintering monarchs were female, whereas in the last decade, 43 per cent were female. The relationship was significant with and without weighting the analyses by sampling effort. Moreover, analysis of a recent three-year dataset of sex ratios revealed no variation among nine separate colonies, so differences in sampling location did not influence the trend. Additional evidence from autumn migration collections appears to confirm that proportions of females are declining, and also suggests the sex ratio is shifting on breeding grounds. While breeding monarchs face a number of threats, one possibility is an increase in prevalence of the protozoan parasite, Ophryocystis elektroscirrha, which recent evidence shows affects females more so than males. Further study will be needed to determine the exact cause of this trend, but for now it should be monitored closely. © 2009 The Royal Society. Source

Pennington D.N.,University of Minnesota | Pennington D.N.,World Wildlife Fund | Blair R.B.,University of Minnesota
Diversity and Distributions | Year: 2011

Aim Urbanization is a leading threat to global biodiversity, yet little is known about how the spatial arrangement and composition of biophysical elements - buildings and vegetation - within a metropolitan area influence habitat selection. Here, we ask: what is the relative importance of the structure and composition of these elements on bird species across multiple spatial scales? Location The temperate metropolitan area of Cincinnati, Ohio, USA. Methods We surveyed breeding birds on 71 plots along an urban gradient. We modelled relative density for 48 bird species in relation to local woody vegetation composition and structure and to tree cover, grass cover and building density within 50-1000m of each plot. We used an information-theoretic approach to compare models and variables. Results At the proximate scale, native tree and understory stem frequency were the most important vegetation variables explaining bird distributions. Species' responses to landscape biophysical features and spatial scales varied. Most native species responded positively to vegetation measures and negatively to building density. Models combining both local vegetation and landscape information represented best or competitive models for the majority of species, while models containing only local vegetation characteristics were rarely competitive. Smaller spatial scales (≤500m) were most important for 36 species, and eight species had best models at larger scales (>500m); however, several species had competitive models across multiple scales. Main conclusions Habitat selection by birds within the urban matrix is the result of a combination of factors operating at both proximate and broader spatial scales. Efforts to manage and design urban areas to benefit native birds require both fine-scale (e.g., individual landowners and landscape design) and larger landscape actions (e.g., regional comprehensive planning). © 2011 Blackwell Publishing Ltd. Source

Barber-Meyer S.M.,World Wildlife Fund
Conservation Biology | Year: 2010

Illegal international trade in wildlife (excluding fisheries and timber) has been valued at more than US$20 billion. A more precise figure has not been determined in part because of the clandestine nature of the trade, and for this same reason even regional and local levels of wildlife trade are difficult to assess. The application of recent developments in wildlife field-survey methods (e.g., occupancy) now allows for a more-accurate estimation of wildlife trade occurrence, including its hidden components at a variety of scales (e.g., regional, local) and periods (e.g., single season, 1 year, multiple years). Occupancy models have been applied in wildlife field studies to address the problem of false absences when conducting presence-absence surveys. Occupancy surveys differ from traditional presence-absence surveys because they incorporate repeat surveys, allowing for the likelihood of detecting a species (the probability of detection) to be estimated explicitly (in contrast to traditional surveys that often incorrectly treat this probability as close to one to allow for estimation of presence). Occupancy methods can be applied to a variety of wildlife-trade surveys, including, for example, single-species availability, links between two illegally traded species (i.e., co-occurrence), and disease occurrence in live trade. In addition, free user-friendly software (i.e., PRESENCE) allows even nonstatisticians to adequately address this issue. I simulated a hypothetical wildlife-trade market survey that resulted in an apparent 20% decline in naïve occupancy (proportion of surveyed towns engaged in the trade) over 2 years, but when I accounted for change in probability of detection over the years the difference in occupancy was not statistically significant. As more sophisticated methods, such as occupancy, are applied to wildlife-trade market surveys, results will be more robust and defensible and therefore, theoretically, more powerful when presented to conservation policy and decision makers. ©2010 Society for Conservation Biology. Source

Ingwersen W.W.,U.S. Environmental Protection Agency | Stevenson M.J.,World Wildlife Fund
Journal of Cleaner Production | Year: 2012

When used to compare the relative environmental performance of different products, life cycle-based, quantitative environmental claims, such as carbon footprint claims and environmental product declarations require common rules in order for claims to be comparable within a category. Product category rules (PCRs), which are defined in the ISO 14025 standard, specify how life cycle environmental impacts should be estimated and reported for products within a given category. The standard has allowed for the development of multiple program operators in different countries, each with its own set of PCRs. We provide a global update on the development of PCRs, describing progress in existing programs and highlighting emerging efforts. As PCRs have begun to proliferate, challenges have arisen that could potentially undermine comparison of life-cycle-based claims for comparable products. These challenges include the definition of the product category, the lack of common data sources, limited geographic scope, and the format of the claim. We present some recommendations on overcoming these challenges and point out some potential mechanisms to support alignment internationally. © 2011 Elsevier Ltd. All rights reserved. Source

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