bluuebunny/crossref_metadata_2025_split huggingface dataset:
Faunal Changes and Bottomland Hardwood Forest Loss in the Tensas Watershed, Louisiana
Authors: BURDICK DAVID M. , CUSHMAN DOUGLAS , HAMILTON ROBERT , GOSSELINK JAMES G. 
Published: April 2005

Abstract:We attempted to associate differences in faunal populations in the Tensas watershed with differences in bottomland hardwood forest area using existing data sets. The Tensas watershed was part of the original range of several species that are now absent red wolf, Florida panther, and Ivory‐Billed Woodpecker The Louisiana black bear and Bachman's Warbler are also threatened with extinction. Bird surveys provided the best faunal data, and comparisons of bird populations (1) with decreases in bottomland hardwood forest over time and (2) in areas with different amounts of forest support the hypotheses that the number of forest species and the population densities of forest interior species decreased with cumulative losses of forest area We have shown the deterioration of indigenous faunal populations using existing bird surveys and qualitative data, demonstrating the utility of a cumulative impact approach at the watershed scale. By insuring the conservation of required habitats, a cumulative impact management plan would reduce further extinctions within this watershed
Genetic Conservation in Feral Populations of Livestock
Authors: van VUREN DIRK , HEDRICK PHILIP W. 
Published: April 2005

Abstract:Feral livestock may be sources of genetic variation with potential commercial, scientific historical, or aesthetic value. Important variants may include primitive traits absent in modern breeds and novel or rare adaptations; the presence of these variants may be suggested directly by morphological markers, quantitative traits, fitness characters, or rare or unique alleles, and indirectly by the extent and duration of isolation, founder number, ancestry, or environmental conditions. Both direct and indirect evidence indicated potentially valuable traits in a population of feral sheep on Santa Cruz Island California and recently 18 lambs were captured to found a mainland population. We discuss several genetic goals important in maintaining a feral population, but caution that such goals must not conflict with the preservation of natural diversity threatened by feral livestock.
Hybridization in the Island Endemic, Catalina Mahogany
Authors: RIESEBERG LOREN H. , ZONA SCOTT , ABERBOM LINDA , MARTIN TERRENCE D. 
Published: April 2005

Abstract: Allozyme data, combined with traditional morphological and anatomical data, were used to evaluate the genetic status of the island endemic, Cercocarpus traskiae (Catalina mahogany). Comprising only seven adult plants and close to 70 seedlings, C. traskiae is confined to Wild Boar Gully on the southwest side of Santa Catalina Island in Los Angeles County, California Electrophoretic examination of 22 enzyme loci revealed that all but two of the seven adult C. traskiae trees were unique allozymically. Furthermore four of the seven C. traskiae individuals were morphologically and/or anatomically intermediate between “true”C. traskiae and the more abundant Cercocarpus species on Santa Catalina, C. betuloides var, blancheae. Further electrophoretic analyses revealed that two of these four individuals possessed an additive “hybrid” enzyme phenotype indicating that these individuals were hybrid. Twenty‐five of the seedlings were also assayed but none of the seedlings displayed hybrid enzyme phenotypes.Given the evidence for hybridization described herein, we make two suggestions to enhance the long‐term preservation of C. traskiae. First, it may be desirable to eliminate the single C. betuloides var.: blancheae individual in Wild Boar Gully. Second, we suggest that established cuttings of true C. traskiae be transplanted to areas on Santa Catalina where the probability of hybridization is minimal Our data further demonstrate that accurate taxonomic identification and an understanding of population genetic structure are necessary for the enlightened management of small relict populations or island endemics.
Genetic Polymorphisms and Their Relationships with Inbreeding and Breed Structure in Rare British Sheep: The Portland, Manx Loghtan, and Hebridean
Authors: CLARKE S. W. , TUCKER E. M. , HALL S. J. G. 
Published: April 2005

Abstract: 320 sheep of three rare British breeds were typed for blood group and biochemical polymorphism. Genetic distance was least between the Manx Loghtan and Hebridean (D = 0.1241, supporting historical evidence of a close relationship between the breeds. Distances to the Portland breed were 0.144 and 0.186, respectively. The claim that the Portland is related to the Dorset Horn was substantiated by the fact that both breeds possess the i blood group allele. Pedigree analysis showed that most rare or unusual alleles in the three bee could be traced to particular ancestors, which had been accepted for registration as foundation stocks, i. e., there was little evidence of genetic introgression from other breeh. Highly inbred sheep showed the predicted lack of heterozygosity.When these sheep were first registered (1973), foundation stocks were defined comprising animals of correct breed type. Today, the pedigree of each sheep reveals the percentages of its ancestry attributable to each foundation stock Sheep were classified according to these percentages into subgroups, each of which, therefore corresponds to a strain within the breed Genetic distances were calculated among these subgroups within each breed For the Portland these distances were rather large (D up to 0.069), but distances were rather small for the other two breeds (D up to 0.027). The Manx Loghtan and Hebridean breeds are therefore relatively homogeneous while the genetic distances among Portland subgroups reveal the genetic consequences of the reproductive isolation of certain important flocks
Allocating Scarce Resources for Conservation of Endangered Subspecies: Partitioning Zoo Space for Tigers
Authors: MAGUIRE LYNN A. , LACY ROBERT C. 
Published: April 2005

Abstract:All remaining subspecies of tigers (Panthera tigris) are endangered in the wild and space for captive breeding in western zoos is limited How should this space be allocated to enhance survival and retention of genetic variation in the face of uncertainty about genetic relationships among tiger subspecies and about the future of tigers in the wild? We solicited expert judgments on subspecies population trends and on the ratio of effective to census size in captivity and analyzed different scenarios for dividing the 1000 captive spaces among four tiger subspecies To maximize survival and retention of gene dimity in individual subspecies, it is best to divide the space equally among the four subspecies To maximize retention of gene diversity for the species as whole, it is better to allocate more space to the subspecies that appears most variable on the basis of limited electrophoretic data (p. t. tigris). Allocating half of the captive space to tigris and dividing the remainder equally among the other three subspecies is a satisfactory compromise between species welfare and subspecies welfare that ensures survival of all four subspecies (at least in captivity) and retains about 80 percent of existing gene diversity within subspecies and about 93 percent of diversity for the species as a whole. Sensitivity analyses showed that our recommendations were robust to uncertainty about the demographic and genetic status of tiger subspecies. For other species with several endangered subspecies; such as rhinos, resource limitations may be too severe to permit an easy compromise between species and subspecies welfare and acquiring better genetic data becomes critical.
An Environment‐metapopulation Approach to Population Viability Analysis for a Threatened Invertebrate
Authors: MURPHY DENNIS D. , FREAS KATHY E. , WEISS STUART B. 
Published: April 2005

Abstract: Most previous population viability analyses of endangered species have focused on large vertebrates: long‐lived species with low rates of population increase, long generation times, and comparatively low habitat specificity. Habitat fragmentation not only reduces the distribution of such species, but reduces population densities to levels at which genetic and demographic constraints threaten population persistence. Many other endangered species, in contrast, are characterized by small body size, high rates of population increase, short generation times, and high habitat specificity. Habitat fragmentation reduces distributions of such species, but within remnant habitats population densities may continue to be high. Population viability analyses for these species — which include many small vertebrates, invertebrates, and plants — must focus on the environmental factors and metapopulation characteristics that determine population persistence. Population viability analysis for the threatened Bay checkerspot butterfly (Euphydryas editha bayensis) exemplifies the environment‐metapopulation approach. Variation in thermal conditions and rainfall through time (macroclimate) and across local topography (topoclimate) drives the population dynamics of this insect. Because of the great sensitivity of larvae and host plants to thermal differences between slope exposures and to annual variation in rainfall, extinction of local butterfly populations is common. Both habitat patch quality (size, topographic diversity, and resource abundance) and distance from a reservoir population affect the likelihood of patch occupancy. An understanding of metapopulation dynamics, therefore, is necessary to explain the regional distribution of the butterfly at any given time.Although parameterization of key life stages of the Bay checkerspot butterfly is not yet complete, insights from previous studies can be used to help make decisions in reserve design and management of the species.
Management Options for Preserving Genetic Diversity: Reintroduction of Guam Rails to the Wild
Authors: HAIG SUSAN M. , BALLOU JONATHAN D. , DERRICKSON SCOTT R. 
Published: April 2005

Abstract: Population management programs recognize the importance of managing genetic diversity in species that are candidates for eventual reintroduction to natural habitats. The planned 1989 release of captive‐born Guam rails (Rallus owstoni), extinct in the wild since 1986, to the Northern Mariana island of Rota provides an opportunity to evaluate various management options for selecting breeders to produce young rails for release. Six options were compared to determine which one best replicated genetic diversity in the original captive founder population. Heterozygosity, allelic dimity, founder contribution, and founder genome equivalents were used as indicators of genetic diversity.

Option 1: Randomly choose adults for breeding.
Option 2: Choose the most fecund captive breeders.
Option 3: Use allozyme data to choose parents that will produce the most genetically diverse chicks.
Option 4: Choose pairs to equalize founder contribution in the population.
Option 5: Choose pairs to maximize allelic diversity.
Option 6: Choose pairs to maximize founder genome equivalents.

Genetic management options based on pedigree analysis (#4, 5, 6) produced the most genetically diverse release populations for Rota. Managing founder genome equivalents produced a balance between equalizing founder contribution and maximizing allelic diversity, and provided the most genetically diverse population. Randomly selecting breeding pain, choosing the best captive breeding stock, or managing by allozyme data resulted in substantially reduced genetic diversity. Results illustrate that some of the most common approaches to population management or population reintroduction may produce significant loss of genetic diversity, whereas certain genetic management options may actually increase genetic diversity over current population levels.
Lands for Long‐Term Research in Conservation Biology
Authors: BILDSTEIN KEITH L. , BRISBIN I. LEHR 
Published: April 2005

Abstract: Success in conservation biology depends upon a synergistic combination of short‐term tactics and long‐term strategies. Although the former are often necessary to forestall immediate habitat losses, the latter provide the critical framework of understanding needed to develop effective short‐term priorities. Although many conservation biologists now emphasize short‐term tactics, prudence dictates the concomitant establishment of long‐term research projects aimed at answering fundamental ecological questions.One deterrent to amassing such long‐term data bases, aside from time and funding, is a lack of suitable sites where such studies can be conducted on a large scale. We describe two established major land‐holding networks in the United States that could serve as appropriate places to develop long‐term studies: the National Science Foundation's Long‐Term Ecological Research (LTER) sites, and the US. Department of Energy's National Environmental Research Parks (NERPs). Because they consist of established research facilities, both networks can provide conservation biologists with “low‐cost” baseline information on ecological processes, as well as access to a number of representative terrestrial and aquatic habitats under more or less “controlled” conditions suitable for long‐term studies. We recommend that conservation biologists explore the possibility of using these or similarly available sites in their research programs.
Assessing Extinction Threats: Toward a Reevaluation of IUCN Threatened Species Categories
Authors: MACE GEORGINA M. , LANDE RUSSELL 
Published: April 2005

Abstract: IUCN categories of threat (Endangered Vulnerable, Rare, Indeterminate, and others) are widely used in‘Red lists’of endangered species and have become an important tool in conservation action at international, national, regional, and thematic levels. The existing definitions are largely subjective, and as a result, categorizations made by different authorities diyfer and my not accurately reflect actual extinction risks. We present proposals to redefine categories in tams of the probability of extinction within a specific time period based on the theory of extinction times for single populations and on meaningful time scales for conservation action. Three categories are proposed (CRITICAL, ENDANGE‐, VULNERABLE) with decreasing levels of threat over increasing time scales for species estimated to have at least a 10% probability of extinction within 100 years. The process of assigning species to categories may need to vay among different taxonomic groups, but we present some simple qualitative criteria based on population biology theory, which we suggest are appropriate at least for most large vertebrates. The process of assessing threat is clearly distinguished from that of setting priorities for conservation action, and only the former is discussed here.Resumen: La categorización de la Uniôn Internacional para la Conservación de la Naturaleza (UICN) de las especies amenazadas (en peligro, vulnerables, raras, indeteminadas y otras) son ampliamente utilizadas en las Listas Rojas de especies en peligro y se ban convertido en una herramienta importante para las acciones de conservacion al nivel internacional, nacional, regional y temático. Las definiciones de las categorias existentes son muy subjetivas y, como resultado, las categorizaciones hechas por diferentes autores dvieren y quizás no reflejen con certeza el riesgo real de extinción. Presentamos propuestas para re‐definir las categoryías en términos de la probabilidad de extinción dentro de un períod de tiempo especifico. Las propuestas estan basadas en la teoría del tiempo de extinción para poblaciones individuales y en escalas de tiempo que tengan significado para las acciones de conservación. Se proponen tres categoryías (CRITICA, EN PELIGRO, VULNERABLE) con niveles decrecientes de amenaza sobre escalas de tiempo en aumento para especies que se estima tengan cuando ménos un 10% deprobabilidad de extinción en 100 años. El proceso de asignar especies a categoryías puede que necesite variar dentro de los diferentes grupos taxóndmicos pero nosotros presentamos algunos criterios cualitativos simples basados en la teoría de la biología de las poblaciones, las cuales suger‐imos son apropiadas para cuando ménos la mayoría de los grandes vertebrados. El proceso de evaluar la amenaza se distingue claramente del de definir las prioridades para las acciones de conservación, sólamente el primero se discute aquí.
The Magnitude of Global Insect Species Richness
Authors: Gaston Kevin J. 
Published: April 2005

Abstract:Recent suggestions that insects number tens of millions of species have received much attention. Little consideration, however, has been given to how such estimates compare with what else we know about insect species richness. Perhaps most significantly, the specialist knowledge of the taxonomic community at large has generally been ignored Collation of published and unpublished information from this source provides little to encourage belief in truly vast numbers of undescribed species of insects. For the insect groups for which figures are available, estimates of global total numbers of species are typically less than ten times the numbers of described species. Although minimum global estimates are more readily constructed than upper estimates, these figures uniformly fail to support assertions that there are 30 million or more species of insects. Rather, a figure of less than ten million seems more tenable, and one of around five million feasible.Additional, more circumstantial, evidence tends to support the idea that insect species numbers may not be as vast as has been claimed First, the contribution of canopy specialists to global richness may be less than often suggested. Second, a higher proportion of species than commonly entertained may have moderate to large geographic ranges. Third, the number of groups failing to increase in richness in the tropics may have been underestimated. Finally, the proportion of undescribed species encountered by many taxonomists seems insufficient to justify estimates of vast species numbers.
Japanese Perceptions of Wildlife
Authors: KELLERT STEPHEN R. 
Published: April 2005

Abstract:This paper examines how the Japanese public perceives the natural world und its conservation, mainly wildlife. Limited comparisons are made to the United States. Data was collected in both countries using similar conceptual and methodological frameworks. Closed‐ended surveys were conducted of random samples of the Japanese and American publics, and in‐depth interviews were conducted with 50 environmentally knowledgeable Japanese.A central interest was the apparent inconsistency of a presumed special Japanese appreciation of nature concurrent with u pattern of widespread environmental abuse extensive@ reported in the literature. The results of this study partially elucidate this paradox. Japanese appreciation for nature was found to be very narrow and idealized, primarily focusing on single species and lacking an ecological and ethical perspective. The Japanese and American publics were both found to possess strong affection for particularly favored species and enjoyed direct experiential contact with individual aspects of the environment. Both cultures were similarly pragmatic toward nature, and somewhat indifferent regarding the environment when it possessed little emotional value. The Japanese public placed far greater value on satisfactions derived from control and mastery over nature. Additionally, the Japanese expressed far less ethical or ecological concern for nature and wildlife than citizens of the United States. Americans also had significantly greater knowledge of wildlife.
On the Ecology, Insect Seed‐Predation, and Conservation of a Rare and Endemic Plant Species: Ebenus amnitagei (Leguminosae)
Authors: HEGAZY AHMAD K. , EESA NAEEM MOHAMED 
Published: April 2005

Abstract: Ebcnus armitagei Schweiuf. et Taub(Leguminosae) is a perennial woody species endemic to the western Mediterranean coast of Egypt and Libya The species is uery rare and restricted to a narrow range of distribution. Growth, phenology, seed output, and predation by the bruchid beetle Callosobruchus maculatus F. (Bruchidae—Coleoptera) of a naturally growing population were monitored. Growth and phenology are highly seasonal and correlated with precipitation and temperature. Up to 48.4% of the population is in the juvenile stages, which experience high mortality. Seed predation is extraordinarily heauy. An auerage of 94.4% of seeds in different stages of maturity are consumed or damaged by C. maculatus. Habitat change and biotic factors within populations including seed predation are threatening the species’existence in the wild.The following are some possible measures for conservation of E. armitagci: (1) small scale habitat conservation (sanctuary), (2) establishment of new populations by artificial means, (3) establishment of a gene (seed) bank, (4) encouraging botanical gardens to conserue the species, and (5) field application of selective insecticides to control the seed predators but not to destroy beneficial insects.
Comparison of the Four Formulas of Adjusting QT Interval for the Heart Rate in the Middle‐Aged Healthy Turkish Men
Authors: Dogan Abdullah , Tunc Ercan , Varol Ercan , Ozaydin Mehmet , Ozturk Mustafa 
Published: April 2005

Objective: The aim of this study was to evaluate the QT intervals at different rest heart rates in healthy middle‐aged Turkish men and to compare the known four QT adjusting methods for heart rate. Methods and Results: The QT intervals were measured in electrocardiograms of 210 healthy men (mean age = 35–60 years). A curve relating QT intervals and heart rates from 45 to 135 beats/min was constructed for study population. Based on the formula of Bazett, Fridericia, and Framingham, adjusted QT intervals in these range of heart rates were separately estimated. An adjusting nomogram for different heart rates was created using a reference value, which was the measured QT interval at heart rate of 60 beats/min (QTNo= QT + correcting number). These four QT correction methods were compared with each other. The reference value of QT interval at heart rate of 60 beats/min was 382 ms. The relationship between QT and RR interval was linear (r = 0.66, P < 0.001). Nomogram method corrected QT interval most accurately for all the heart rates compared with other three adjusting methods. At heart rates of 60–100 beats/min, the equation of linear regression was QT = 237 + 0.158 × RR (P < 0.001). Bazett's formula gave the poorest results at all the heart rates. The formulas of Fridericia and Framingham were superior to Bazett's formula; however, they overestimated QT interval at heart rate of 60–110 beats/min (P < 0.01). At lower rates (<60 beats/min), all methods except nomogram method, underestimated QT interval (P = 0.03). Conclusion: Among four QT correction formulas, the nomogram method provides the most accurately adjusted values of QT interval for all the heart rates in healthy men. Bazett's formula fails to adjust the QT interval for all the heart rates.