14 results on '"Pimm, Stuart L."'
Search Results
2. The distribution and numbers of cheetah (Acinonyx jubatus) in southern Africa
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Weise, Florian J., Vijay, Varsha, Jacobson, Andrew P., Schoonover, Rebecca F., Groom, Rosemary J., Horgan, Jane, Keeping, Derek, Klein, Rebecca, Marnewick, Kelly, Maude, Glyn, Melzheimer, Jörg, Mills, Gus, van der Merwe, Vincent, van der Meer, Esther, van Vuuren, Rudie J., Wachter, Bettina, Pimm, Stuart L., and Roberts, David
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0106 biological sciences ,0301 basic medicine ,Population ,Endangered species ,lcsh:Medicine ,Distribution ,010603 evolutionary biology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Species of concern ,Crowd-sourcing ,Leslie Matrix model ,Southern Africa ,Cheetah ,biology.animal ,Acinonyx jubatus ,IUCN Red List ,education ,education.field_of_study ,biology ,business.industry ,General Neuroscience ,lcsh:R ,General Medicine ,15. Life on land ,Fishery ,030104 developmental biology ,Geography ,Habitat ,Threatened species ,Livestock ,General Agricultural and Biological Sciences ,business - Abstract
Assessing the numbers and distribution of threatened species is a central challenge in conservation, often made difficult because the species of concern are rare and elusive. For some predators, this may be compounded by their being sparsely distributed over large areas. Such is the case with the cheetahAcinonyx jubatus.The IUCN Red List process solicits comments, is democratic, transparent, widely-used, and has recently assessed the species. Here, we present additional methods to that process and provide quantitative approaches that may afford greater detail and a benchmark against which to compare future assessments. The cheetah poses challenges, but also affords unique opportunities. It is photogenic, allowing the compilation of thousands of crowd-sourced data. It is also persecuted for killing livestock, enabling estimation of local population densities from the numbers persecuted. Documented instances of persecution in areas with known human and livestock density mean that these data can provide an estimate of where the species may or may not occur in areas without observational data. Compilations of extensive telemetry data coupled with nearly 20,000 additional observations from 39 sources show that free-ranging cheetahs were present across approximately 789,700 km2of Namibia, Botswana, South Africa, and Zimbabwe (56%, 22%, 12% and 10% respectively) from 2010 to 2016, with an estimated adult population of 3,577 animals. We identified a further 742,800 km2of potential cheetah habitat within the study region with low human and livestock densities, where another ∼3,250 cheetahs may occur. Unlike many previous estimates, we make the data available and provide explicit information on exactly where cheetahs occur, or are unlikely to occur. We stress the value of gathering data from public sources though these data were mostly from well-visited protected areas. There is a contiguous, transboundary population of cheetah in southern Africa, known to be the largest in the world. We suggest that this population is more threatened than believed due to the concentration of about 55% of free-ranging individuals in two ecoregions. This area overlaps with commercial farmland with high persecution risk; adult cheetahs were removed at the rate of 0.3 individuals per 100 km2per year. Our population estimate for confirmed cheetah presence areas is 11% lower than the IUCN’s current assessment for the same region, lending additional support to the recent call for the up-listing of this species from vulnerable to endangered status.
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- 2017
3. Erratum to: Habitat fragmentation and biodiversity conservation: key findings and future challenges
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Wilson, Maxwell C, Chen, Xiao-Yong, Corlett, Richard T, Didham, Raphael K, Ding, Ping, Holt, Robert D, Holyoak, Marcel, Hu, Guang, Hughes, Alice C, Jiang, Lin, Laurance, William F, Liu, Jiajia, Pimm, Stuart L, Robinson, Scott K, Russo, Sabrina E, Si, Xingfeng, Wilcove, David S, Wu, Jianguo, and Yu, Mingjian
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Ecology ,Earth Sciences ,Biological Sciences ,Environmental Sciences - Published
- 2016
4. Quantitative analysis of forest fragmentation in the atlantic forest reveals more threatened bird species than the current red list
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Schnell, Jessica K., Harris, Grant M., Pimm, Stuart L., and Russell, Gareth J.
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Metapopulation Dynamics ,Conservation of Natural Resources ,Ecological Metrics ,Science ,Population Dynamics ,Models, Biological ,Trees ,Birds ,Ornithology ,ddc:570 ,Animals ,Passeriformes ,Biology ,Species Extinction ,Ecosystem ,Conservation Science ,Population Density ,Ecology ,Population Biology ,Geography ,Endangered Species ,Computational Biology ,Biodiversity ,Extinction Risk ,Medicine ,Population Ecology ,Zoology ,Algorithms ,Brazil ,Research Article - Abstract
Habitat loss and attendant fragmentation threaten the existence of many species. Conserving these species requires a straightforward and objective method that quantifies how these factors affect their survival. Therefore, we compared a variety of metrics that assess habitat fragmentation in bird ranges, using the geographical ranges of 127 forest endemic passerine birds inhabiting the Atlantic Forest of Brazil. A common, non-biological metric - cumulative area of size-ranked fragments within a species range - was misleading, as the least threatened species had the most habitat fragmentation. Instead, we recommend a modified version of metapopulation capacity. The metric links detailed spatial information on fragment sizes and spatial configuration to the birds' abilities to occupy and disperse across large areas (100,000+ km(2)). In the Atlantic Forest, metapopulation capacities were largely bimodal, in that most species' ranges had either low capacity (high risk of extinction) or high capacity (very small risk of extinction). This pattern persisted within taxonomically and ecologically homogenous groups, indicating that it is driven by fragmentation patterns and not differences in species ecology. Worryingly, we found IUCN considers some 28 of 58 species in the low metapopulation capacity cluster to not be threatened. We propose that assessing the effect of fragmentation will separate species more clearly into distinct risk categories than does a simple assessment of remaining habitat.
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- 2013
5. The trees, if not the woods The Sixth Extinction: An Unnatural History Elizabeth Kolbert (Henry Holt and Co., New York, NY; 2014) ISBN-10: 0805092994
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Pimm, Stuart L.
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Unknown
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6. Incorporating explicit geospatial data shows more species at risk of extinction than the current Red List
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Ocampo-Peñuela, Natalia, Jenkins, Clinton N., Vijay, Varsha, Li, Binbin V., and Pimm, Stuart L.
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remote sensing ,threatened species ,Red List ,birds ,conservation ,14. Life underwater ,15. Life on land ,GIS - Abstract
The IUCN (International Union for Conservation of Nature) Red List classifies species according to their risk of extinction, informing global to local conservation decisions. Unfortunately, important geospatial data do not explicitly or efficiently enter this process. Rapid growth in the availability of remotely sensed observations provides fine-scale data on elevation and increasingly sophisticated characterizations of land cover and its changes. These data readily show that species are likely not present within many areas within the overall envelopes of their distributions. Additionally, global databases on protected areas inform how extensively ranges are protected. We selected 586 endemic and threatened forest bird species from six of the world’s most biodiverse and threatened places (Atlantic Forest of Brazil, Central America, Western Andes of Colombia, Madagascar, Sumatra, and Southeast Asia). The Red List deems 18% of these species to be threatened (15 critically endangered, 29 endangered, and 64 vulnerable). Inevitably, after refining ranges by elevation and forest cover, ranges shrink. Do they do so consistently? For example, refined ranges of critically endangered species might reduce by (say) 50% but so might the ranges of endangered, vulnerable, and nonthreatened species. Critically, this is not the case. We find that 43% of species fall below the range threshold where comparable species are deemed threatened. Some 210 bird species belong in a higher-threat category than the current Red List placement, including 189 species that are currently deemed nonthreatened. Incorporating readily available spatial data substantially increases the numbers of species that should be considered at risk and alters priority areas for conservation., Science Advances, 2 (11), ISSN:2375-2548
7. Batch-produced, GIS-informed range maps for birds based on provenanced, crowd-sourced data inform conservation assessments
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Claudia Hermes, Stuart H. M. Butchart, Clinton N. Jenkins, Ryan M. Huang, Hannah Wheatley, Stuart L. Pimm, Alison Johnston, Christopher L. Wood, Binbin V. Li, Natalia Ocampo-Peñuela, Wilderson Medina, John W. Fitzpatrick, Thomas M. Brooks, Daniel J. Lebbin, Michael J. Parr, David A. Wiedenfeld, Huang, Ryan M [0000-0002-1198-8611], Hermes, Claudia [0000-0002-5106-0869], Jenkins, Clinton N [0000-0003-2198-0637], Wheatley, Hannah [0000-0003-0042-7365], Pimm, Stuart L [0000-0003-4206-2456], Apollo - University of Cambridge Repository, and University of St Andrews. Statistics
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Species Delimitation ,Conservation Biology ,Range (biology) ,QH301 Biology ,Speciation ,Endangered species ,Forests ,Critically endangered ,SDG 13 - Climate Action ,Vulnerable species ,Psychology ,QA ,SDG 15 - Life on Land ,Conservation Science ,Numerical Analysis ,Multidisciplinary ,Near-threatened species ,Ecology ,Animal Behavior ,FOS: Social sciences ,Eukaryota ,Terrestrial Environments ,Habitats ,Physical sciences ,Geography ,Habitat ,Vertebrates ,Medicine ,Crowdsourcing ,Research Article ,Evolutionary Processes ,Science ,Ecology and environmental sciences ,FOS: Physical sciences ,Ecosystems ,Social sciences ,Birds ,QH301 ,Animals ,QA Mathematics ,Evolutionary Biology ,Behavior ,Biology and life sciences ,Endangered Species ,Least concern ,Organisms ,DAS ,Interpolation ,Threatened species ,Amniotes ,Geographic Information Systems ,Animal Migration ,Physical geography ,Zoology ,Mathematics - Abstract
Accurate maps of species ranges are essential to inform conservation, but time-consuming to produce and update. Given the pace of change of knowledge about species distributions and shifts in ranges under climate change and land use, a need exists for timely mapping approaches that enable batch processing employing widely available data. We develop a systematic approach of batch-processing range maps and derived Area of Habitat maps for terrestrial bird species with published ranges below 125,000 km2 in Central and South America. (Area of Habitat is the habitat available to a species within its range.) We combine existing range maps with the rapidly expanding crowd-sourced eBird data of presences and absences from frequently surveyed locations, plus readily accessible, high resolution satellite data on forest cover and elevation to map the Area of Habitat available to each species. Users can interrogate the maps produced to see details of the observations that contributed to the ranges. Previous estimates of Areas of Habitat were constrained within the published ranges and thus were, by definition, smaller—typically about 30%. This reflects how little habitat within suitable elevation ranges exists within the published ranges. Our results show that on average, Areas of Habitat are 12% larger than published ranges, reflecting the often-considerable extent that eBird records expand the known distributions of species. Interestingly, there are substantial differences between threatened and non-threatened species. Some 40% of Critically Endangered, 43% of Endangered, and 55% of Vulnerable species have Areas of Habitat larger than their published ranges, compared with 31% for Near Threatened and Least Concern species. The important finding for conservation is that threatened species are generally more widespread than previously estimated.
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- 2021
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8. Conservation Through Population Assessments Across Variable Landscapes
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Huang, Ryan and Pimm, Stuart L
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Seabirds ,Conservation biology ,Wildlife conservation ,Corridors ,Wildlife management ,Mangroves ,Metapopulation ,Conservation ,Population biology - Abstract
Dissertation, Few areas of the planet are untouched by human actions, be they marine or terrestrial. Marine habitats face disturbance from overexploitation of fisheries and pollution while terrestrial habitats face significant threat from land cover conversion and degradation. To address these threats, conservationists utilize a variety of population viability analyses to both assess and manage species’ health. The results of these analyses often play a key role in determining when intervention is necessary and which actions will be the most successful. Within this dissertation, I used several population modeling approaches to advance our understanding of changes in the landscape on the persistence of populations and by extension, species.This dissertation may be broadly divided into two halves, the first assessing a single, local population and the second evaluating metapopulations. In Chapter 2, I combined telemetry data on sooty terns (Onychoprion fuscatus) with a long-term capture-mark-recapture dataset from the Dry Tortugas National Park to map the movements at sea for this species, calculate estimates of mortality, and investigate the impact of hurricanes on a migratory seabird. Included in the latter analysis is information on the locations of recovered bands from deceased individuals wrecked by tropical storms. I present the first known map of sooty tern migration in the Atlantic Ocean. The results indicate that the birds had minor overlaps with areas affected by the major 2010 oil spill and a major shrimp fishery. Indices of hurricane strength and occurrence are positively correlated with annual mortality and indices of numbers of wrecked birds. As climate change may lead to an increase in severity and frequency of major hurricanes, this may pose a long-term problem for this colony.In the latter half of this dissertation, I utilized a variety of metapopulation analyses for conservation at multiple scales. As a landscape becomes increasingly fragmented through habitat loss, the individual patches become smaller and more isolated and thus less likely to sustain a local population. Metapopulation theory is appropriate for analyzing fragmented landscapes because it combines empirical landscapes features with species-specific information to produce direct information on population extinction risks. Combining a spatially explicit metapopulation model with empirical data on endemic species’ ranges and maps of habitat cover, I could calculate the metapopulation capacity— a measure of a landscape’s ability to sustain a metapopulation. Mangroves provide an ideal, model landscape for my analysis in Chapter 3. Of conservation concern, one can easily delineate their patch boundaries. I calculated metapopulation capacity for 99 metapopulations from 32 different mangrove-endemic bird species globally in the years 2000 and 2015. Northern Australia and South East Asia have the highest richness of mangrove-endemic birds, with some hotspots also occurring in Guyana and French Guiana. The areas with the highest metapopulation loss are the Caribbean, the Pacific coast of Central America, Madagascar, Borneo, and isolated patches in Southeast Asia in Burma and Malaysia. Regions with the highest loss of habitat area are not necessarily those with the highest loss of metapopulation capacity. Often it is not a matter of how much, but how the habitat is lost since fragmentation of patches has a complicated relationship with extinction risk. After analyzing the effects of habitat loss and fragmentation on a species’ risk of extinction, it is natural to examine the reverse, the restoration of habitat. In Chapter 4, I used metapopulation models to prioritize locations for potential habitat corridors. I compared these results to standard connectivity models that have grown in popularity to illustrate how together they provide a more complete set of recommendations for the recovery of species. For this chapter, I use the golden lion tamarin (Leontopithecus rosalia) as the focal species. Endemic to the highly fragmented Atlantic coastal forest of Brazil, the golden lion tamarins are a highly studied species of top conservation concern. I identified the best locations for habitat restoration to increase metapopulation capacity and how they compare with movement of individuals in the current landscape. I also evaluated how a previous corridor restoration ranked according to these methods and how it effects future conservation planning. While large, occupied patches are significant for both sets of models, metapopulation models also indicate the importance of nearby, medium-sized empty patches that if connected by a corridor would facilitate the growth and recovery of tamarin populations.In summary, I applied a suite of population modeling techniques to an assortment of landscapes and species for conserving biodiversity. Despite the variety of models used, I illustrate the flexibility and utility of population ecology to conservation management.
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- 2019
9. Conservation of endemic species in China
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Binbin, LI and Pimm, Stuart L
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Conservation biology ,protected area ,endemic species ,giant panda ,priority setting ,non-invasive survey method ,biodiversity - Abstract
China is one of the most biodiverse countries in the world, harboring more than 10% of the species in the world. Among them, 11% of the vertebrate genera and 7% plant genera are endemic to China. During its rapid social and economic development, increasing habitat loss and fragmentation have occurred. However, it wakes up to the threats of biodiversity in recent years. Protected areas, as an essential conservation tool to reduce habitat loss and species extinction have expanded dramatically in China. Protected areas with various other concepts such as umbrella species and payment for ecosystem services have been promoted to conserve the biodiversity. However, questions remain that whether they work, how they work and how we could do better. It is crucial to answer these questions with the data and technology that are more available to us now. Thus, my dissertation divides into four chapters and tackles the following four questions. 1) Where do the most of the endemic species concentrate in China? Do umbrellas species such as giant pandas effectively protect other species? 2) With the increasing of tree plantation and available remote sensing data, how does it change the available habitat for forest species, their threat levels and priority setting? 3) Within the conservation priority areas, new threats that are hardly detected by traditional evaluation index such as forest cover emerge. How does a prevalent human disturbance - livestock grazing impact the conservation of giant pandas? What are the socio-economic drivers and solutions to this issue? 4) To better monitor the population and evaluate conservation efforts, new techniques need to be added. Can we use footprints from wild pandas to identify individuals and provide a cost-effective alternative to the current methods?In Chapter 1, I first used detailed data on geographical ranges for endemic forest species to identify patterns of species richness. After refining each species' range by its known elevational range and remaining forest habitats as determined from remote sensing, I identified the top 5% richest areas as the centers of endemism. Over 96% of the panda habitat overlapped the endemic centers. Thus, investing in almost any panda habitats will benefit many other endemics. Existing panda national nature reserves cover all but one of the endemic species that overlap with the panda’s distribution. For whole China, of particular interest are 14 mammal, 20 bird, and 82 amphibian species that are inadequately protected. Most of these the IUCN currently deems threatened. But 7 mammal, 3 bird, and 20 amphibian species are currently non-threatened, yet their geographical ranges are In Chapter 2, I used remote sensing data to differentiate oil palm and rubber plantation from natural forests in Southeast Asia and reevaluated the threat level of endemic forest species identified by IUCN. Tropical, mainland Southeast Asia is under exceptional threat, yet relatively poorly known. This region contains over 122, 183, and 214 endemic mammals, birds, and amphibians, respectively, of which the IUCN considers 37, 21, and 37 threatened. When corrected for the amount of remaining natural habitats, the average sizes of species ranges shrink to Chapter three focuses on a specific threat - livestock grazing in the endemic center that I identified in the first chapter. With the Natural Forest Conservation Program and Grain to Green programs, the deforestation that was once the biggest threat to pandas has been halted. However, a previously unrecognized threat is emerging. Livestock grazing has become the most prevalent human disturbance throughout panda habitats. I applied field sign survey, vegetation survey, GPS collar tracking, and species distribution modeling to study how the livestock grazing impacts the habitat use of giant pandas. This study shows that livestock grazing especially from horses has caused a dramatic decline in bamboos and reduced its regeneration. In the past 15 years, pandas have changed its habitat use and are driven out of areas that are heavily used by livestock. 49% of panda habitat has been lost especially in the lower elevation areas from 2004 till now due to impacts of livestock. Loss of income because of the policies Natural Forest Conservation Project and Grain for Green projects, reduced tourists because of dam construction and earthquake, encouraged horse riding practice during the development of ICDP have contributed to the increasing dependence on livestock sector. Livestock ban with payment for ecosystem services or feedlot operation could be possible solutions for this issue.Chapter four explores the innovative technique to identify giant panda individuals to facilitate better conservation. Two methods have been used previously to identify individuals and population for giant pandas, fecal bamboo bite size combined with home range analysis and microsatellite analysis of fecal DNA. However, the first one suffers from the lack of accuracy and the latter one is limited by the freshness of the fecal sample and high cost. I developed the footprint identification technique in JMP based on two multivariate methods: discriminant analysis and the canonical centroid plot method using the anatomy measurements of footprints. I used 30 captive pandas to develop the algorithm and 11 individuals for validation. The overall accuracy of FIT for individual identification is 90% and sex discrimination is 85%. This technique is embedded in FIT as an add-in and free for conservation practitioners now. In summary, this dissertation includes the following four papers. Chapter 1, Li and Pimm. 2016. China's endemic vertebrates sheltering under the protective umbrella of the giant panda. Conservation Biology 30:329-339.Chapter 2, Li et al., 2016. Remotely sensed data informs Red List evaluations and conservation priorities in Southeast Asia. PloS one, 11(8), e0160566.Chapter 3, Li et al., Emerging threat from livestock on giant panda conservationChapter 4, Li et al., Identifying individual and sex of giant pandas through Footprint Identification Technique.With supporting information from the following publication during my Ph.D.:Li, B. et al. 2014. Effects of feral cats on the evolution of anti-predator behaviours in island reptiles: insights from an ancient introduction. Proc. R. Soc. B 281: 20140339.Ocampo-Peñuela, N., Jenkins, C. N, Vijay, V., Li, B.V., & Pimm., S.L. 2016. Incorporating explicit geospatial data shows more species at risk of extinction than the current Red List. Science Advances, 2(11), e1601367.Pimm, S.L., Harris, G., Jenkins, C.N., Ocampo-Peñuela, N. & Li, B.V. 2016 Unfulfilled promise of data-driven approaches: response to Peterson et al. Conservation Biology, In press.
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- 2017
10. Using Bird Distributions to Assess Extinction Risk and Identify Conservation Priorities in Biodiversity Hotspots
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Ocampo-Penuela, Natalia and Pimm, Stuart L
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conservation priorities ,geographical ranges ,Ecology ,Conservation biology ,birds ,threat categories ,Colombia ,Geographic information science and geodesy ,biodiversity hotspots - Abstract
Habitat loss, fragmentation, and degradation threaten the World’s ecosystems and species. These, and other threats, will likely be exacerbated by climate change. Due to a limited budget for conservation, we are forced to prioritize a few areas over others. These places are selected based on their uniqueness and vulnerability. One of the most famous examples is the biodiversity hotspots: areas where large quantities of endemic species meet alarming rates of habitat loss. Most of these places are in the tropics, where species have smaller ranges, diversity is higher, and ecosystems are most threatened. Species distributions are useful to understand ecological theory and evaluate extinction risk. Small-ranged species, or those endemic to one place, are more vulnerable to extinction than widely distributed species. However, current range maps often overestimate the distribution of species, including areas that are not within the suitable elevation or habitat for a species. Consequently, assessment of extinction risk using these maps could underestimate vulnerability.In order to be effective in our quest to conserve the World’s most important places we must: 1) Translate global and national priorities into practical local actions, 2) Find synergies between biodiversity conservation and human welfare, 3) Evaluate the different dimensions of threats, in order to design effective conservation measures and prepare for future threats, and 4) Improve the methods used to evaluate species’ extinction risk and prioritize areas for conservation. The purpose of this dissertation is to address these points in Colombia and other global biodiversity hotspots.In Chapter 2, I identified the global, strategic conservation priorities and then downscaled to practical local actions within the selected priorities in Colombia. I used existing range maps of 171 bird species to identify priority conservation areas that would protect the greatest number of species at risk in Colombia (endemic and small-ranged species). The Western Andes had the highest concentrations of such species—100 in total—but the lowest densities of national parks. I then adjusted the priorities for this region by refining these species ranges by selecting only areas of suitable elevation and remaining habitat. The estimated ranges of these species shrank by 18–100% after accounting for habitat and suitable elevation. Setting conservation priorities on the basis of currently available range maps excluded priority areas in the Western Andes and, by extension, likely elsewhere and for other taxa. By incorporating detailed maps of remaining natural habitats, I made practical recommendations for conservation actions. One recommendation was to restore forest connections to a patch of cloud forest about to become isolated from the main Andes.For Chapter 3, I identified areas where bird conservation met ecosystem service protection in the Central Andes of Colombia. Inspired by the November 11th (2011) landslide event near Manizales, and the current poor results of Colombia’s Article 111 of Law 99 of 1993 as a conservation measure in this country, I set out to prioritize conservation and restoration areas where landslide prevention would complement bird conservation in the Central Andes. This area is one of the most biodiverse places on Earth, but also one of the most threatened. Using the case of the Rio Blanco Reserve, near Manizales, I identified areas for conservation where endemic and small-range bird diversity was high, and where landslide risk was also high. I further prioritized restoration areas by overlapping these conservation priorities with a forest cover map. Restoring forests in bare areas of high landslide risk and important bird diversity yields benefits for both biodiversity and people. I developed a simple landslide susceptibility model using slope, forest cover, aspect, and stream proximity. Using publicly available bird range maps, refined by elevation, I mapped concentrations of endemic and small-range bird species. I identified 1.54 km2 of potential restoration areas in the Rio Blanco Reserve, and 886 km2 in the Central Andes region. By prioritizing these areas, I facilitate the application of Article 111 which requires local and regional governments to invest in land purchases for the conservation of watersheds.Chapter 4 dealt with elevational ranges of montane birds and the impact of lowland deforestation on their ranges in the Western Andes of Colombia, an important biodiversity hotspot. Using point counts and mist-nets, I surveyed six altitudinal transects spanning 2200 to 2800m. Three transects were forested from 2200 to 2800m, and three were partially deforested with forest cover only above 2400m. I compared abundance-weighted mean elevation, minimum elevation, and elevational range width. In addition to analyzing the effect of deforestation on 134 species, I tested its impact within trophic guilds and habitat preference groups. Abundance-weighted mean and minimum elevations were not significantly different between forested and partially deforested transects. Range width was marginally different: as expected, ranges were larger in forested transects. Species in different trophic guilds and habitat preference categories showed different trends. These results suggest that deforestation may affect species’ elevational ranges, even within the forest that remains. Climate change will likely exacerbate harmful impacts of deforestation on species’ elevational distributions. Future conservation strategies need to account for this by protecting connected forest tracts across a wide range of elevations. In Chapter 5, I refine the ranges of 726 species from six biodiversity hotspots by suitable elevation and habitat. This set of 172 bird species for the Atlantic Forest, 138 for Central America, 100 for the Western Andes of Colombia, 57 for Madagascar, 102 for Sumatra, and 157 for Southeast Asia met the criteria for range size, endemism, threat, and forest use. Of these 586 species, the Red List deems 108 to be threatened: 15 critically endangered, 29 endangered, and 64 vulnerable. When ranges are refined by elevational limits and remaining forest cover, 10 of those critically endangered species have ranges < 100km2, but then so do 2 endangered species, seven vulnerable, and eight non-threatened ones. Similarly, 4 critically endangered species, 20 endangered, and 12 vulnerable species have refined ranges < 5000km2, but so do 66 non-threatened species. A striking 89% of these species I have classified in higher threat categories have
- Published
- 2016
11. Remote Sensing of Fire, Flooding, and White Sand Ecosystems in the Amazon
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Adeney, Jennifer Marion, Pimm, Stuart L, and Christensen, Norman L
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remote sensing ,Wetlands ,conservation ,Biology, Ecology ,Hydrology ,Amazon ,fire ,tropical ecosystems - Abstract
Human and natural disturbance affect the Amazon basin at several spatial and temporal scales. In this thesis, I used satellite-detected hot pixels to examine patterns of human-caused disturbance and protected areas in the Brazilian Amazon from 1996-2006. Deforestation fires, as measured by hot pixels, declined exponentially with increasing distance from roads. Fewer deforestation fires occurred within protected areas than outside and this difference was greatest near roads. However, even within reserves, more deforestation fires occurred in regions with high human impact than in those with lower impact. El Niño-related droughts affected deforestation fires most outside of reserves and near roads. There was no significant difference in fire occurrence among inhabited and uninhabited reserve types. Within this context of disturbance in the Brazilian Amazon basin, I examined relatively undisturbed savanna-like `campina' ecosystems. I reviewed the literature on campinas and discussed their variation and their significance for beta diversity. As one of two case studies, I assessed spatio-temporal patterns of disturbance (fire and blowdowns), and vegetation change from 1987 to 2007 in campinas in the central Brazilian Amazon using Landsat imagery. In 2001 images, an increase in open areas corresponded with significantly more visible signs of disturbance, likely precipitated by the 1997-98 El Niño. Bird community data indicated a trend of more generalist/savanna species in more frequently disturbed campinas. As the second case study, I used daily 500 m resolution MODIS reflectance data to assess seasonal and inter-annual flooding in ~33,000 km2 of campinas in the Negro river basin. Flooding cycles of these wetland campinas critically influence regional ecosystem processes. Flooded areas ranged from 15,000 km2 at the end of the rainy season (August-Oct) to little, if any, open water in the driest times (Jan-Mar). Predictable seasonal flood pulses occurred, but also displayed high inter-annual variability. This variability was weakly correlated with the Multivariate El Niño Southern Oscillation Index (MEI). Campina ecosystems are an important, but largely overlooked, component of the biodiversity of the Amazon basin. My research shows that climate, particularly ENSO-associated droughts, strongly affects campinas even in remote areas, just as it increases fire frequencies in more populated regions of the Amazon.
- Published
- 2009
12. A tale of three disciplines: Navigating the Boundaries at the Nexus of Conservation Science, Policy, and Practice
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Hickey, Valerie and Pimm, Stuart L.
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Political Science, General ,Environmental Sciences - Abstract
Nature is under immediate and increasing threat. Tales of destruction and deforestation abound despite the myriad interventions and investments by government bureaucracies, non-government organizations, and private land-owners. As the extinction crisis looms larger and demands on the public purse grow greater, understanding how science becomes policy and policy practice is more important than ever. As a result, and in response to the increasing insularity of conservation biology that has consciously nourished a careful separation of knowledge and action, of scientist and actor, I use this dissertation to navigate the nexus of conservation science, policy, and practice. I employ case studies in forest hydrology and species conservation, as well as cognitive theory, to examine how conservation science becomes policy. I collected field data from Lake Mead National Recreation Area and from the World Bank to explore how policies are translated into practice. Current assumptions in conservation biology apportions these three separate but equal disciplines - science, policy, and practice - into one greater and two lesser, one that is pure and two that are sticky. But the transmission of knowledge from the Academy to the domains of conservation policy and practice, though difficult, is our mandate. As much as technical competence matters in conservation biology, so too does political literacy. After all, conservation occurs within a dynamic social, political, and institutional landscape. Nonetheless, the current emphasis in conservation biology is on answering questions in the natural sciences and, to a lesser degree, in economics. This focus is important, as is protecting scholarship from the daily pressures of a society that demands quick and ready answers. But scientific data is only one commodity among many that policy-makers and conservation practitioners trade in a tournament of values. Its usefulness lies in the wider social and political environment. Moreover, conservation biology is not simply an applied subset of biology or ecology. It is a mission-driven discipline that dedicates itself to the pursuit of science to save wildlife and wild lands. It encapsulates certain values as axioms. We hold these truths to be self-evident: that the diversity of life matters and that the struggle to end extinctions is meaningful. Therefore, though conservation science, the design of conservation policies, and the practice of conservation are separate disciplines, they are closely related. For we must understand their different rules of evidence, speak their distinctive languages, and achieve credibility in all three disciplines while maintaining a sense of intellectual integrity in each. This requires respect for their differences as well as recognizing their shared mission in the service of wildlife and wild lands.
- Published
- 2009
13. Conserving Moving Species under Changing Landscapes and Climates
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Loarie, Scott Robbins and Pimm, Stuart L
- Subjects
species distributions ,Statistics ,conservation ,Climate change ,ecology ,Environmental Sciences ,animal movement - Abstract
To conserve biodiversity, it is critical to understand the dynamic landscapes and climates through which species move and how the environment influences movement choices. In particular, I am interested in how species respond to human modifications to landscapes and climates. Chapter 1 uses datasets on the spatial and temporal coverage of remotely sensed land cover datasets to examine gaps in the monitoring of environmental priorities. Temporal gaps in Landsat and spatial gaps in commercial high resolution satellites such as QuickBird may hinder land cover change monitoring efforts.Chapter 2 uses Global Climate Models and museum specimens to projects the impact of climate change on the flora of California, a global biodiversity hotspot. With anticipated climate change, up to 66% may experience >80% reductions in range size within a century. These projections are less severe if plants are able to disperse in time. With no constraints on dispersal, plant centroids move an average of up to 150 km. The projections identify regions where species undergoing severe range reductions may persist. Protecting these potential future refugia and facilitating species dispersal may be essential to maintain biodiversity in the face of climate change.Chapter 3 analyzes the movements of 73 elephants fitted with GPS collars against 4 remotely sensed datasets spanning a strong rainfall gradient across 7 southern African countries. Movements show strong seasonal and geographic differences across the study area. Two major human interventions, artificial water and fences, distort these movement patterns by increasing dry season ranging patterns and increasing the density of wet season movements.Chapter 4 uses the datasets described in chapter 3 to explore elephant vegetation preferences. Elephants consistently prefer greener vegetation throughout the year. Vegetation preferences vary seasonally. Elephants prefer less variable vegetation such as forests in the dry season and ephemeral vegetation such as grasslands in the wet season.Chapter 5 uses telemetry and remotely sensed landcover data to ask how climatic factors - snow cover - and land cover - agriculture and roads - influence pronghorn movements in South Eastern Alberta. Analysis using a Bayesian movement model reveals that each of these features significantly influences pronghorn movement choices.
- Published
- 2008
14. Avian Distribution Patterns and Conservation in Amazonia
- Author
-
Vale, Mariana M, Pimm, Stuart L., and Alves, Maria Alice S.
- Subjects
Birds ,Amazonia ,Biology, Ecology ,Biodiversity ,Conservation ,Indigenous People - Abstract
In this dissertation, I address the distribution and conservation of the Amazonian avifauna at several different scales. In Chapter 1, I looked at how the spatial bias in ornithological collections affects our understanding of the patterns of diversity in Amazonia. I showed that Amazonia is massively under-collected, that biological collection sites cluster around points of access, and that the richness at collection localities is higher than would be expected at random. This greater richness in collected areas was associated with a higher proportion of species with small geographical ranges as compared to uncollected areas. These small range species are relevant for conservation, as they are especially prone to extinction. I concluded that the richness of the uncollected areas of Amazonia is seriously underestimated, and that current knowledge gaps preclude accurate selection of areas for conservation in Amazonia. With this in mind, I modeled the impacts of continued deforestation on the Amazonian endemic avifauna. To overcome knowledge gaps, I complemented bird range maps with a "bird-ecoregions." I identified several taxa and bird-ecoregions likely to face great threat in the near future, most of them associated with riverine habitats. To evaluate these predictions, I conducted a detailed study on two riverine species: the Rio Branco Antbird (Cercomacra carbonaria) and the Hoary-throated Spinetail (Synallaxis kollari). Both are threatened and endemic to the gallery forests of Roraima, Brazil. I predicted that both would lose critical habitat in the near future. I concluded that neither is categorized correctly in by The World Conservation Union and recommend the down-listing of the Rio-Branco-Antbird and the up-listing of the Hoary-throated Spinetail. I also explored the importance of indigenous reserves for the conservation of both species and emphasized the need for greater involvement of conservation biologists in the social issues related to their study organisms.
- Published
- 2007
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