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Kinds of Wildlife Terms modified by Wildlife Selected AbstractsUSING RESERVES TO PROTECT FISH AND WILDLIFE SIMPLIFIED MODELING APPROACHESNATURAL RESOURCE MODELING, Issue 2 2005OLA FLAATEN ABSTRACT. This paper investigates theoretically to what extent a nature reserve may protect a uniformly distributed population of fish or wildlife against negative effects of harvesting. Two objectives of this protection are considered: avoidance of population extinction and maintenance of population, at or above a given precautionary population level. The pre-reserve population is assumed to follow the logistic growth law and two models for post-reserve population dynamics are formulated and discussed. For Model A by assumption the logistic growth law with a common carrying capacity is valid also for the post-reserve population growth. In Model B, it is assumed that each sub-population has its own carrying capacity proportionate to its distribution area. For both models, migration from the high-density area to the low-density area is proportional to the density difference. For both models there are two possible outcomes, either a unique globally stable equilibrium, or extinction. The latter may occur when the exploitation effort is above a threshold that is derived explicitly for both models. However, when the migration rate is less than the growth rate both models imply that the reserve can be chosen so that extinction cannot occur. For the opposite case, when migration is large compared to natural growth, a reserve as the only management tool cannot assure survival of the population, but the specific way it increases critical effort is discussed. [source] EXPLOITING MARINE WILDLIFE IN QUEENSLAND: THE COMMERCIAL DUGONG AND MARINE TURTLE FISHERIES, 1847,1969AUSTRALIAN ECONOMIC HISTORY REVIEW, Issue 3 2008Ben Daley commercial fisheries; dugongs; Great Barrier Reef; marine turtles; Australia The historical exploitation of marine resources in Queensland has only been partially documented. In particular, the history of the commercial fishing of dugongs and marine turtles has received comparatively little scholarly attention. Since European settlement in Queensland, various human activities have exploited these resources. We present documentary and oral history evidence of the scale of those industries. Based on extensive archival and oral history research, we argue that diverse fishing practices occurred and that the sustained exploitation of dugongs, green turtles, and hawksbill turtles led to observable declines in the numbers of these animals , now species of conservation concern. [source] GM Sugar Beets Benefit WildlifeCONSERVATION, Issue 2 2005Article first published online: 8 MAR 200 No abstract is available for this article. [source] The Ecological Future of the North American Bison: Conceiving Long-Term, Large-Scale Conservation of WildlifeCONSERVATION BIOLOGY, Issue 2 2008ERIC W. SANDERSON Bison bison; conservación de especies; Declaración de Vermejo; metas de conservación; representación ecológica Abstract:,Many wide-ranging mammal species have experienced significant declines over the last 200 years; restoring these species will require long-term, large-scale recovery efforts. We highlight 5 attributes of a recent range-wide vision-setting exercise for ecological recovery of the North American bison (Bison bison) that are broadly applicable to other species and restoration targets. The result of the exercise, the "Vermejo Statement" on bison restoration, is explicitly (1) large scale, (2) long term, (3) inclusive, (4) fulfilling of different values, and (5) ambitious. It reads, in part, "Over the next century, the ecological recovery of the North American bison will occur when multiple large herds move freely across extensive landscapes within all major habitats of their historic range, interacting in ecologically significant ways with the fullest possible set of other native species, and inspiring, sustaining and connecting human cultures." We refined the vision into a scorecard that illustrates how individual bison herds can contribute to the vision. We also developed a set of maps and analyzed the current and potential future distributions of bison on the basis of expert assessment. Although more than 500,000 bison exist in North America today, we estimated they occupy <1% of their historical range and in no place express the full range of ecological and social values of previous times. By formulating an inclusive, affirmative, and specific vision through consultation with a wide range of stakeholders, we hope to provide a foundation for conservation of bison, and other wide-ranging species, over the next 100 years. Resumen:,Muchas especies de mamíferos de distribución amplia han experimentado declinaciones significativas durante los últimos 200 años; la restauración de estas especies requerirá esfuerzos de recuperación a largo plazo y a gran escala. Resaltamos 5 atributos de un reciente ejercicio de gran visión para la recuperación ecológica del bisonte de Norte América (Bison bison) que son aplicables en lo general a otras especies y objetivos de restauración. El resultado del ejercicio, la "Declaración de Vermejo", explícitamente es (1) de gran escala, (2) de largo plazo, (3) incluyente, (4) satisfactor de valores diferentes y (5) ambicioso. En parte, establece que "En el próximo siglo, la recuperación ecológica del Bisonte de Norte América ocurrirá cuando múltiples manadas se desplacen libremente en los extensos paisajes de todos los hábitats importantes en su rango de distribución histórica, interactúen de manera significativa ecológicamente con el conjunto más completo de otras especies nativas e inspiren, sostengan y conecten culturas humanas." Refinamos esta visión en una tarjeta de puntuación que ilustra cómo las manadas de bisonte individuales pueden contribuir a la visión. También desarrollamos un conjunto de mapas y analizamos las distribuciones actuales y potencialmente futuras del bisonte con base en la evaluación de expertos. Aunque actualmente existen más de 500,000 bisontes en Norte América, estimamos que ocupan <1% de su distribución histórica y no expresan el rango completo de valores ecológicos y culturales de otros tiempos. Mediante la formulación de una visión incluyente, afirmativa y específica basada en la consulta a una amplia gama de interesados, esperamos proporcionar un fundamento para la conservación del bisonte, y otras especies de distribución amplia, para los próximos 100 años. [source] Wildlife and Politics: CAMPFIRE in ZimbabweDEVELOPMENT AND CHANGE, Issue 3 2000Jocelyn Alexander CAMPFIRE programmes have been hailed internationally for the innovative ways in which they have sought to confront the challenges of some of Africa's most marginal regions through the promotion of local control over wildlife management. In Zimbabwe, CAMPFIRE has been cast as an antidote to the colonial legacy of technocratic and authoritarian development which had undermined people's control over their environment and criminalized their use of game. This article explores why such a potentially positive programme went so badly wrong in the case of Nkayi and Lupane districts, raising points of wider significance for comparable initiatives. Local histories and institutional politics need careful examination. The first part of the article thus investigates the historical forces which shaped attitudes to game, while the second part considers the powerful institutional and economic forces which conspired to sideline these historically formed local views. CAMPFIRE in Nkayi and Lupane was further shaped by the legacies of post-independence state violence in this region, and the failure of earlier wildlife projects. This range of factors combined to create deep distrust of CAMPFIRE, and quickly led to open confrontation. [source] 5th International Symposium on Physiology, Behaviour and Conservation of Wildlife, Berlin 2004ETHOLOGY, Issue 2004Article first published online: 2 DEC 200 First page of article [source] Conservation and collection efforts for the endangered Alabama sturgeon (Scaphirhynchus suttkusi)JOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2007S. J. Rider Summary The Alabama sturgeon (Scaphirhynchus suttkusi) is the rarest and most endangered sturgeon species in North America. Over an 8-year period, the Alabama Division of Wildlife and Freshwater Fisheries, U.S. Army Corps of Engineers, and U.S. Fish and Wildlife Service cumulatively expended 2447 man-days in efforts to collect Alabama sturgeon broodstock in an attempt to initiate a conservation propagation program. Out of nearly 29 000 fishes collected between March 1997 and May 2005, only five were Alabama sturgeon. Attempts to spawn and propagate these sturgeons were unsuccessful, and all have since died in captivity. In context with past collection efforts and anecdotal accounts, these results indicate that the Alabama sturgeon is becoming increasingly rare with the passage of time. Although there is evidence that some level of recruitment continued to occur in the Alabama River during the past decade, the increasing rarity of Alabama sturgeon suggests that mortality rates are exceeding recruitment. [source] Expansion of human settlement in Kenya's Maasai Mara: what future for pastoralism and wildlife?JOURNAL OF BIOGEOGRAPHY, Issue 6 2004Richard H. Lamprey Abstract Aim, Wildlife and pastoral peoples have lived side-by-side in the Mara ecosystem of south-western Kenya for at least 2000 years. Recent changes in human population and landuse are jeopardizing this co-existence. The aim of the study is to determine the viability of pastoralism and wildlife conservation in Maasai ranches around the Maasai Mara National Reserve (MMNR). Location, A study area of 2250 km2 was selected in the northern part of the Serengeti-Mara ecosystem, encompassing group ranches adjoining the MMNR. Emphasis is placed on Koyake Group Ranch, a rangeland area owned by Maasai pastoralists, and one of Kenya's major wildlife tourism areas. Methods, Maasai settlement patterns, vegetation, livestock numbers and wildlife numbers were analysed over a 50-year period. Settlement distributions and vegetation changes were determined from aerial photography and aerial surveys of 1950, 1961, 1967, 1974, 1983 and 1999. Livestock and wildlife numbers were determined from re-analysis of systematic reconnaissance flights conducted by the Kenya Government from 1977 to 2000, and from ground counts in 2002. Corroborating data on livestock numbers were obtained from aerial photography of Maasai settlements in 2001. Trends in livestock were related to rainfall, and to vegetation production as indicated by the seasonal Normalized Difference Vegetation Index. With these data sets, per capita livestock holdings were determined for the period 1980,2000, a period of fluctuating rainfall and primary production. Results, For the first half of the twentieth century, the Mara was infested with tsetse-flies, and the Maasai were confined to the Lemek Valley area to the north of the MMNR. During the early 1960s, active tsetse-control measures by both government and the Maasai led to the destruction of woodlands across the Mara and the retreat of tsetse flies. The Maasai were then able to expand their settlement area south towards MMNR. Meanwhile, wildebeest (Connochaetes taurinus) from the increasing Serengeti population began to spill into the Mara rangelands each dry season, leading to direct competition between livestock and wildlife. Group ranches were established in the area in 1970 to formalize land tenure for the Maasai. By the late 1980s, with rapid population growth, new settlement areas had been established at Talek and other parts adjacent to the MMNR. Over the period 1983,99, the number of Maasai bomas in Koyake has increased at 6.4% per annum (pa), and the human population at 4.4% pa. Over the same period, cattle numbers on Koyake varied from 20,000 to 45,000 (average 25,000), in relation to total rainfall received over the previous 2 years. The rangelands of the Mara cannot support a greater cattle population under current pastoral practices. Conclusions, With the rapid increase in human settlement in the Mara, and with imminent land privatization, it is probable that wildlife populations on Koyake will decline significantly in the next 3,5 years. Per capita livestock holdings on the ranch have now fallen to three livestock units/reference adult, well below minimum pastoral subsistence requirements. During the 1980s and 90s the Maasai diversified their livelihoods to generate revenues from tourism, small-scale agriculture and land-leases for mechanized cultivation. However, there is a massive imbalance in tourism incomes in favour of a small elite. In 1999 the membership of Koyake voted to subdivide the ranch into individual holdings. In 2003 the subdivision survey allocated plots of 60 ha average size to 1020 ranch members. This land privatization may result in increased cultivation and fencing, the exclusion of wildlife, and the decline of tourism as a revenue generator. This unique pastoral/wildlife system will shortly be lost unless land holdings can be managed to maintain the free movement of livestock and wildlife. [source] Translocations: Providing Outcomes for Wildlife, Resource Managers, Scientists, and the Human CommunityRESTORATION ECOLOGY, Issue 2 2008Kevin A. Parker Abstract The World Conservation Union (1987) defines a translocation as a release of animals with the intention of establishing, reestablishing, or augmenting an existing population. Despite frequent use as a tool for the management of threatened and endangered wildlife, the full benefits of translocations often go unrealized. In this article, I demonstrate how translocations can achieve outputs for conservation management, conservation science, and the wider human community, using North Island (NI) Saddleback or Tieke (Philesturnus rufusater) as an illustrative example. From a conservation management perspective, NI Saddleback have been salvaged from a relic population of less than 500 birds on 484-ha Hen Island to a metapopulation of approximately 6,000 birds on 13 offshore islands and at two mainland New Zealand sites. These translocations have reduced the risk of global extinction for this species and helped restore the ecosystems involved. All these translocations have occurred in the past 42 years from known source populations and with known numbers of birds released. The resulting replicated serial population bottlenecks provide numerous scientific opportunities for conservation and biological research. Although the first Saddleback translocations were to reserves closed to the public, subsequent translocations have been to open reserves, providing the wider human community with an opportunity to see and be actively involved in the management of a threatened endemic species. This has raised the profile of both NI Saddleback and other species and has provided wider community conservation benefits. These three outputs illustrate the value of translocations for resource management and conservation science and for increasing community interest, participation, and investment in biological conservation. [source] Duck Hunting and Wetland Conservation: Compromise or Synergy?CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2003Jeff Bennett Duck hunting is an issue , often controversial , that generates both benefits and costs to society. Hunters enjoy benefits from engaging in their sport, while those who have ethical concerns regarding the shooting of ducks endure costs. Some in the community fear that duck hunting puts pressure on the continued ecological viability of the hunted species, while others argue that the demand for hunting provides sufficient economic incentive for wetland conservation. Whether society as a whole should permit or restrict duck hunting is to some extent an empirical question: Are the costs to society of allowing duck hunting greater or less than the benefits it generates? Evidence presented in this paper addresses this question. The benefits enjoyed by people who hunt ducks in the upper south east of South Australia are estimated using the travel cost method. The ethical costs borne by the general community because of duck hunting are estimated using the choice modeling technique. Finally a threshold value analysis is used to assess the activities of Wetlands and Wildlife, a not-for-profit organization that manages wetlands in part for hunting. La chasse au canard est un sujet qui prête souvent à controverse et qui est une source de coûts et d'avantages pour la société. Les chasseurs profitent des avantages que leur procure leur sport, tandis que ceux qui ont des préoccupations d'ordre moral touchant à la chasse subissent des coûts. Certaines personnes dans la communauté craignent que la chasse au canard ne fasse pression sur la viabilitéécologique des espèces chassées. Est-ce que la société dans son ensemble devrait permettre ou limiter la chasse au canard est dans une certaine mesure une question empirique: est-ce que les coûts pour la société de permettre la chasse excèdent ou non les avantages qu'elle procure? Les données présentées dans cet article répondent à cette question. Les avantages reçus par ceux qui chassent le canard dans le haut du sud-est de l'Australie du Sud sont estimés en utilisant la méthode du coût de transport. Les coûts d'ordre moral subis par la communauté dans son ensemble à cause de la chasse au canard sont estimés en utilisant la technique de modélisation des choix. Enfin, une analyse de valeur seuil est utilisée pour évaluer les activités de Zones Aquifères et Nature, un organisme bénévole qui gère les zones aquifères en partie pour la chasse. [source] Developmental toxicity of estrogenic chemicals on rodents and other speciesCONGENITAL ANOMALIES, Issue 2 2002Taisen Iguchi ABSTRACT, Antenatal sex-hormone exposure induces lesions in mouse reproductive organs, which are similar to those in humans exposed in utero to a synthetic estrogen, diethylstilbestrol. The developing organisms including rodents, fish and amphibians are particularly sensitive to exposure to estrogenic chemicals during a critical window. Exposure to estrogens during the critical period induces long-term changes in reproductive as well as non-reproductive organs, including persistent molecular alterations. The antenatal mouse model can be utilized as an indicator of possible long-term consequences of exposure to exogenous estrogenic compounds including possible environmental endocrine disrupters. Many chemicals released into the environment potentially disrupt the endocrine system in wildlife and humans, some of which exhibit estrogenic activity by binding to the estrogen receptors. Estrogen responsive genes, therefore, need to be identified to understand the molecular basis of estrogenic actions. In order to understand molecular mechanisms of estrogenic chemicals on developing organisms, we are identifying estrogen responsive genes using cDNA microarray, quantitative RT-PCR, and differential display methods, and genes related to the estrogen-independent vaginal changes in mice induced by estrogens during the critical window. In this review, discussion of our own findings related to endocrine distuptor issue will be provided. [source] Endocrine disruptor issues in JapanCONGENITAL ANOMALIES, Issue 2 2002Taisen Iguchi ABSTRACT, Monitoring of environmental chemicals in Japan has revealed that several endocrine active chemicals are in river water, sediments, and wildlife as well as in the human umbilical cord. In 2001, risk assessments of tributyltin and nonylphenol have been conducted by the Ministry of the Environment, Japan. Risk assessments of di(2-ethylhexyl)phthalate and di-isononyl phthalate have also been performed by the Ministry of Health, Labour and Welfare using a toxicological point of view in 2001. In this review, an overview of recent progress in endocrine disruptor research in Japan will be provided. [source] Forks in the Road: Choices in Procedures for Designing Wildland LinkagesCONSERVATION BIOLOGY, Issue 4 2008PAUL BEIER análisis de sensibilidad; conectividad; corredor de vida silvestre; enlace; diseño de reservas Abstract:,Models are commonly used to identify lands that will best maintain the ability of wildlife to move between wildland blocks through matrix lands after the remaining matrix has become incompatible with wildlife movement. We offer a roadmap of 16 choices and assumptions that arise in designing linkages to facilitate movement or gene flow of focal species between 2 or more predefined wildland blocks. We recommend designing linkages to serve multiple (rather than one) focal species likely to serve as a collective umbrella for all native species and ecological processes, explicitly acknowledging untested assumptions, and using uncertainty analysis to illustrate potential effects of model uncertainty. Such uncertainty is best displayed to stakeholders as maps of modeled linkages under different assumptions. We also recommend modeling corridor dwellers (species that require more than one generation to move their genes between wildland blocks) differently from passage species (for which an individual can move between wildland blocks within a few weeks). We identify a problem, which we call the subjective translation problem, that arises because the analyst must subjectively decide how to translate measurements of resource selection into resistance. This problem can be overcome by estimating resistance from observations of animal movement, genetic distances, or interpatch movements. There is room for substantial improvement in the procedures used to design linkages robust to climate change and in tools that allow stakeholders to compare an optimal linkage design to alternative designs that minimize costs or achieve other conservation goals. Resumen:,Los modelos son utilizados comúnmente para identificar tierras que mantengan la habilidad de la vida silvestre para moverse entre bloques de tierras silvestres a través de una matriz de tierras que habían sido incompatibles con el movimiento de vida silvestre. Ofrecemos 16 opciones y supuestos que se originan en el diseño de enlaces para facilitar el movimiento o el flujo de genes de especies focales entre 2 o más bloques de tierras silvestres predefinidos. Recomendamos el diseño de enlaces que sirvan a múltiples (y solo a una) especies focales que funjan como una sombrilla colectiva para todas las especies nativas y los procesos ecológicos, que explícitamente admitan supuestos no comprobados y que utilicen análisis de incertidumbre para ilustrar efectos potenciales de la incertidumbre del modelo. La mejor forma de mostrar tal incertidumbre a los interesados es mediante mapas de los enlaces modelados bajo diferentes suposiciones. También recomendamos modelar a habitantes de corredores (especies que requieren más de una generación para mover sus genes entre bloques de tierra silvestre) de manera diferente que las especies pasajeras (un individuo se puede mover entre bloques de tierras silvestres en unas cuantas semanas). Identificamos un problema, que denominamos el problema de traducción subjetiva, que surge porque un analista debe decidir subjetivamente cómo traducir medidas de selección de recursos a resistencia. Este problema puede ser sobrepuesto mediante la estimación de la resistencia a partir de observaciones de movimientos de animales, distancias genéticas o movimientos entre fragmentos. Hay espacio para la mejora sustancial de los procedimientos utilizados para diseñar enlaces robustos ante el cambio climático y en herramientas que permiten que los interesados comparen un diseño óptimo con diseños alternativos que minimicen costos o alcancen otras metas de conservación. [source] Discrepancies in Reported Levels of International Wildlife TradeCONSERVATION BIOLOGY, Issue 6 2005ARTHUR G. BLUNDELL aduanas; CITES; especies en peligro; programa de aranceles armonizados Abstract:,The international wildlife trade is a principal cause of biodiversity loss, involving hundreds of millions of plants and animals each year, yet wildlife trade records are notoriously unreliable. We assessed the precision of wildlife trade reports for the United States, the world's largest consumer of endangered wildlife, by comparing data from the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) with U.S. Customs data. For both U.S. imports and exports, CITES and Customs reported substantially different trade volumes for all taxa in all years. Discrepancies ranged from a CITES-reported volume 376% greater than that reported by Customs (live coral imports, 2000) to a Customs' report 5202% greater than CITES (conch exports, 2000). These widely divergent data suggest widespread inaccuracies that may distort the perceived risk of targeted wildlife exploitation, leading to misallocation of management resources and less effective conservation strategies. Conservation scientists and practitioners should reexamine assumptions regarding the significance of the international wildlife trade. Resumen:,El comercio internacional de vida silvestre es una causa principal de la pérdida de biodiversidad, ya que involucra a cientos de millones de plantas y animales cada año; no obstante eso, los registros del comercio son notoriamente poco confiables. Evaluamos la precisión de los registros de comercio de vida silvestre de Estados Unidos, el mayor consumidor de vida silvestre en peligro en el mundo, mediante la comparación de datos del Convenio Internacional para el Comercio de Especies de Flora y Fauna Silvestre en Peligro (CITES) con datos de la Aduana de E.U.A. Tanto para importaciones como exportaciones, CITES y Aduana reportaron volúmenes de comercio de todos los taxa sustancialmente diferentes en todos los años. Las discrepancias abarcaron desde un volumen reportado por CITES 376% más grande que el reportado por la Aduana (importaciones de coral vivo, 2000) hasta un reporte de la Aduana 5202% mayor que el de CITES (exportaciones de caracol, 2000). Estos datos ampliamente divergentes sugieren imprecisiones generalizadas que pueden distorsionar el riesgo percibido por la explotación de vida silvestre, lo que conducirá a la incorrecta asignación de recursos para la gestión y a estrategias de conservación menos efectivas. Los científicos y profesionales de la conservación deberían reexaminar sus suposiciones respecto al significado del comercio internacional de vida silvestre. [source] Physiological and Behavioral Differences in Magellanic Penguin Chicks in Undisturbed and Tourist-Visited Locations of a ColonyCONSERVATION BIOLOGY, Issue 5 2005BRIAN G. WALKER corticoesterona; ecoturismo; perturbación humana; Spheniscus magellanicus Abstract:,Studies examining anthropogenic effects on wildlife typically focus on adults and on behavioral responses rather than the physiological consequences of human disturbances. Here we examined how Magellanic Penguin ( Spheniscus magellanicus) chicks living in either tourist-visited or undisturbed areas of a breeding colony were affected by human visitation by comparing the baseline and stress-induced levels of corticosterone during three periods of the breeding season. Newly hatched chicks in visited areas had higher corticosterone stress responses than newly hatched chicks in undisturbed areas (p =0.007), but baseline levels were similar (p =0.61). By 40,50 days of age and around fledging time, both visited and undisturbed chicks showed a robust corticosterone stress response to capture. Tourist-visited chicks did not flee when approached by humans, however, whereas undisturbed chicks fled significantly sooner (i.e., when approached no closer than 9 m; p < 0.0001). Although it is unknown whether Magellanic Penguin chicks raised in visited areas suffer negative consequences from the elevation of the corticosterone stress response at hatching, they do exhibit behavioral habituation to human contact by the time they are ready to fledge. Unlike adults living in tourist areas, however, fledging chicks in visited areas do not have a decreased stress response to capture and restraint. Our results show that the coupling of behavioral and physiological habituation in Magellanic Penguins is complex and life-history context may greatly affect the ability of wildlife to adapt to anthropogenic disturbances. Resumen:,Los estudios de los efectos antropogénicos sobre la vida silvestre se centran típicamente en adultos y en las respuestas conductuales en lugar de las consecuencias fisiológicas de las perturbaciones humanas. Aquí examinamos el efecto de la visita de humanos sobre pollos de pingüino (Spheniscus magellanicus) en áreas visitadas por turistas o no perturbadas mediante la comparación de los niveles, base e inducidos por estrés, de corticoesterona durante tres períodos de la temporada reproductiva. Los pollos recién eclosionados en áreas visitadas tuvieron mayor respuesta de la corticoesterona al estrés que los pollos recién eclosionados en áreas no perturbadas (p =0.007), pero los niveles básicos fueron similares (p =0.61). A los 40,50 días y en la etapa de volantón, los pollos visitados y no perturbados mostraron una marcada respuesta de la corticoesterona al estrés al ser capturados. Sin embargo, los pollos visitados por turistas no huyeron cuando se les acercaron humanos, mientras que los pollos no perturbados huyeron significativamente antes (i.e., acercamiento a más de 9 m; p < 0.0001). Aunque se desconoce si los pollos de pingüino criados en áreas visitadas sufren consecuencias negativas por la elevación de la corticosterona en respuesta al estrés al eclosionar, si presentan acostumbramiento conductual al contacto con humanos al momento que están listos para dejar el nido. Sin embargo, a diferencia de adultos que viven en áreas turísticas, los pollos volantones en las áreas visitadas no tienen una disminución en la respuesta al estrés cuando son capturados y sujetados. Nuestros resultados muestran la complejidad de la combinación del acostumbramiento conductual y fisiológico en Spheniscus magellanicus y que el contexto de la historia de vida puede afectar a la habilidad de la vida silvestre para adaptarse a las perturbaciones antropogénicas. [source] Roads, Development, and Conservation in the Congo BasinCONSERVATION BIOLOGY, Issue 6 2000David Wilkie Research in the Republic of Congo shows that roads established and maintained by logging concessions intensify bushmeat hunting by providing hunters greater access to relatively unexploited populations of forest wildlife and by lowering hunters' costs to transport bushmeat to market. Reconciling the contrary effects of roads on economic development and biodiversity conservation is one of the key challenges to wildlife managers in all nations. As the Democratic Republic of Congo prepares to reconstruct its almost completely collapsed road system, the government, donors, and conservation organizations have a unique opportunity to strategically prioritize investment in segments of the network that would maximize local and national economic benefits while minimizing adverse effects on forest wildlife. Resumen: La densidad de carreteras está estrechamente ligada al acceso a mercados, el crecimiento económico, la explotación de recursos naturales, la fragmentación del hábitat, la deforestación y la desaparición de tierras y vida silvestre. Investigación en la República del Congo muestra que las carreteras establecidas y mantenidas por las concesiones para tala de árboles intensifican la cacería al proveer a los cazadores un mayor acceso a poblaciones forestales de vida silvestre relativamente sin explotar y al disminuir el costo de transporte de la carne obtenida por la caza hacia el mercado. La reconciliación de los efectos contrarios de las carreteras en el desarrollo económico y la conservación de la biodiversidad es uno de los retos clave para los manejadores de vida silvestre en todas las naciones. A medida que la República Democrática del Congo se prepara para reconstruir su casi completamente colapsado sistema carretero, el gobierno, los donadores y las organizaciones no gubernamentales conservacionistas tienen una oportunidad única para priorizar estratégicamente las inversiones en segmentos de la red carretera que podrían maximizar los beneficios económicos locales y nacionales al mismo tiempo que se minimicen los impactos adversos sobre la vida silvestre forestal. [source] Consumers' taste for rarity drives sturgeons to extinctionCONSERVATION LETTERS, Issue 5 2008Agnès Gault Abstract The international market for luxury goods puts pressure on many wildlife species, with potentially irreversible consequences for many of them. Although classical economic theory suggests that trade alone would not drive a rare species to extinction, in practice numerous species are being threatened by overexploitation. This is for example the case for sturgeons, exploited for their caviar, of which all 27 species are threatened with extinction. We performed a caviar-tasting experiment, combined with a modeling approach merging ecological theory and psychosociology. This allowed us to demonstrate that the human predisposition to place exaggerated value on rarity drives sturgeons' overexploitation, despite caviar's ever-increasing price and the imminent loss of these species. These findings suggest that this mechanism probably drives the entire market for wildlife based luxury goods. [source] Native wildlife on rangelands to minimize methane and produce lower-emission meat: kangaroos versus livestockCONSERVATION LETTERS, Issue 3 2008George R. Wilson Abstract Ruminant livestock produce the greenhouse gas methane and so contribute to global warming and biodiversity reduction. Methane from the foregut of cattle and sheep constitutes 11% of Australia's total greenhouse gas emissions (GHG). Kangaroos, on the other hand, are nonruminant forestomach fermenters that produce negligible amounts of methane. We quantified the GHG savings Australia could make if livestock were reduced on the rangelands where kangaroo harvesting occurs and kangaroo numbers increased to 175 million to produce same amount of meat. Removing 7 million cattle and 36 million sheep by 2020 would lower Australia's GHG emissions by 16 megatonnes, or 3% of Australia's annual emissions. However, the change will require large cultural and social adjustments and reinvestment. Trials are underway based on international experiences of managing free-ranging species. They are enabling collaboration between farmers, and if they also show benefits to sustainability, rural productivity, and conservation of biodiversity, they could be expanded to incorporate change on the scale of this article. Farmers have few options to reduce the contribution that livestock make to GHG production. Using kangaroos to produce low-emission meat is an option for the Australian rangelands which would avoid permit fees under Australia's Emissions Trading Scheme, and could even have global application. [source] Mutant Ecologies: Radioactive Life in Post,Cold War New MexicoCULTURAL ANTHROPOLOGY, Issue 4 2004Joseph Masco A political ecology of the nuclear age developed through a theorization of "mutation" interrogates the contemporary terms of radioactive nature in New Mexico. As an analytic, the value of "mutation" is its emphasis on multigenerational effects, enabling an assessment of biosocial transformations as, alternatively, injury, improvement, or noise. Cold War radiation experiments, the post,Cold War transformation of nuclear production sites into "wildlife reserves," and the expanding role that biological beings play as "environmental sentinels" in New Mexico are all sites where concerns about "species" integrity may be articulated in relation to radioactive nature. [source] Global Environmental Governance and the Challenge of Shadow States: The Impact of Illicit Sapphire Mining in MadagascarDEVELOPMENT AND CHANGE, Issue 5 2005Rosaleen Duffy The environment has become a key site of global governance because of its transboundary nature: forests, wildlife and oceans have all become central foci for networks of global governance which link international organizations, international financial institutions, states and non-governmental organizations. This article examines how contemporary forms of global governance can be challenged and even subverted. It uses the concept of shadow states introduced by William Reno to explore how invisible global networks flow through developing states, to show how they constitute important political and economic interest groups, and to assess what kinds of environmental impact they have. It explores how powerful these networks are, and whether they are able to challenge or subvert attempts to manage, control or govern the environment. The author provides an analysis of the ways in which the clandestine networks of shadow states impact on conservation initiatives in the developing world, focusing on the features of global environmental governance and the problems posed by illicit gem mining and trafficking in Madagascar. [source] Conservation Narratives in Costa Rica: Conflict and Co-existenceDEVELOPMENT AND CHANGE, Issue 1 2002Lisa M. Campbell This article examines narratives about nature conservation in Costa Rica, specifically those related to wildlife and biodiversity, and their evolution with the growth of tourism and bioprospecting industries. It outlines a traditional conservation narrative and two streams of an emerging counter-narrative, and discusses problems and prospects for each in contemporary Costa Rica. The use of narrative and counter-narrative follows Roe (1991, 1995), Fairhead and Leach (1995), and Leach and Mearns (1996). The article focuses particularly on the ways in which the narratives are increasingly drawing on, informing, and sometimes conflicting with one another; it is based on the author's research undertaken in various protected areas in Costa Rica since 1994 and on research published by others. [source] The spatial distribution of badgers, setts and latrines: the risk for intra-specific and badger-livestock disease transmissionECOGRAPHY, Issue 4 2008Monika Böhm The spatial distribution of wildlife hosts and the associated environmental distribution of their excretory products are important factors associated with the risk of disease transmission between wildlife and livestock. At a landscape scale, heterogeneous distribution of a wildlife host will create regional hot spots for disease risk, while at the farm level, distributional patterns of wildlife excretory products as well as habitat use are of primary importance to the assessment of disease risk to livestock. In the UK, badgers have been implicated in the transmission of bovine tuberculosis to cattle. In this study, we focus on the spatial and social organization and habitat use of badgers as well as the distributions of their excretions at latrine and sett sites to assess intra- and inter-species (badger,cattle) disease risk. Across the study site, badger latrines and setts were found in prominent clusters, at distances of up to 250 and 200 m respectively. This was partly due to small-scale clustering of latrines around sett sites, so that disease risk may be higher within the vicinity of setts. The clustered distribution suggests that sites of high risk for TB transmission may be localised within farms. Exclusion of cattle from the few sett and latrine sites within their grazing pasture is therefore likely to provide an effective way of reducing the risk of disease transmission. We also found evidence of social sub-division within badger social groups based on differences in the use of main and outlier setts. This may contribute to localised clusters of infection within the badger population, resulting in heterogeneous patterns of environmental disease risk to the wider host community. A greater understanding of variation in host behaviour and its implications for patterns of disease will allow the development of more targeted and effective management strategies for wildlife disease in group-living hosts. [source] Spillover edge effects: the dispersal of agriculturally subsidized insect natural enemies into adjacent natural habitatsECOLOGY LETTERS, Issue 5 2006Tatyana A. Rand Abstract The cross-edge spillover of subsidized predators from anthropogenic to natural habitats is an important process affecting wildlife, especially bird, populations in fragmented landscapes. However, the importance of the spillover of insect natural enemies from agricultural to natural habitats is unknown, despite the abundance of studies examining movement in the opposite direction. Here, we synthesize studies from various ecological sub-disciplines to suggest that spillover of agriculturally subsidized insect natural enemies may be an important process affecting prey populations in natural habitat fragments. This contention is based on (1) the ubiquity of agricultural,natural edges in human dominated landscapes; (2) the substantial literature illustrating that crop and natural habitats share important insect predators; and (3) the clear importance of the landscape matrix, specifically distance to ecological edges, in influencing predator impacts in agroecosystems. Further support emerges from theory on the importance of cross-boundary subsidies for within site consumer,resource dynamics. In particular, high productivity and temporally variable resource abundance in agricultural systems are predicted to result in strong spillover effects. More empirical work examining the prevalence and significance of such natural enemy spillover will be critical to a broader understanding of fragmentation impacts on insect predator,prey interactions. [source] Parasites in the food web: linking amphibian malformations and aquatic eutrophicationECOLOGY LETTERS, Issue 7 2004Pieter T. J. Johnson Abstract Emerging diseases are an ever-growing affliction of both humans and wildlife. By exploring recent increases in amphibian malformations (e.g. extra or missing limbs), we illustrate the importance of food web theory and community ecology for understanding and controlling emerging infections. Evidence points to a native parasite, Ribeiroia ondatrae, as the primary culprit of these malformations, but reasons for the increase have remained conjectural. We suggest that the increase is a consequence of complex changes to aquatic food webs resulting from anthropogenic disturbance. Our results implicate cultural eutrophication as a driver of elevated parasitic infection: (1) eutrophication causes a predator-mediated shift in snail species composition toward Planorbella spp., (2) Planorbella are the exclusive first intermediate hosts of R. ondatrae and (3) Ribeiroia infection is a strong predictor of amphibian malformation levels. Our study illustrates how the effects of anthropogenic disturbance on epidemic disease can be mediated through direct and indirect changes in food web structure. [source] Effects of fires on butterfly assemblages in lowland dipterocarp forest in East KalimantanENTOMOLOGICAL SCIENCE, Issue 2 2007Toshiya HIROWATARI Abstract The post-fire butterfly fauna in lowland dipterocarp forest of the Bukit Soeharto Education Forest (BSEF), East Kalimantan, Indonesia, was assessed during the period November 1998,April 2000 by means of consecutive Malaise trap samples, with supplementary field observations for March,April 1999. A total of 514 butterflies belonging to 61 species and representing six families were caught in the traps. Melanitis leda (Nymphalidae: Satyrinae), Charaxes bernardus (Nymphalidae: Charaxinae), and Danaus genutia (Nymphalidae: Danainae) were the species most frequently caught (60, 52 and 47 individuals, respectively), representing 31% of the total. These three species are generalists and "disturbance indicators" for tropical rainforest, being characteristic of disturbed or secondary forests, being distributed widely, and having larvae that feed on a wide range of host plants. In contrast, other species, such as Trogonoptera brookiana and Troides amphrysus, were recorded before the fires but were not recorded again afterwards. The pre- and post-fire butterfly fauna of East Kalimantan were compared on the basis of butterfly specimens deposited in the Tropical Rain Forest Research Center that were collected in and around the Bukit Soeharto Education Forest before the fires (1988,1995). On the basis of the post-fire survey, based on Malaise trap samples and field observations, only 43% of the butterfly species (not including Lycaenidae and Hesperiidae) were confirmed to have persisted. The data suggest that refugia that are not affected by fire are necessary for the conservation of specialist butterflies, as well as many other forms of wildlife. [source] Aroclor 1254 alters morphology, survival, and gene expression in Xenopus laevis tadpolesENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2002Anna M. Jelaso Abstract PCBs are persistent environmental contaminants that cause a variety of adverse health effects in wildlife and humans. This article describes the use of signature gene expression patterns that link increased PCB exposure with progressive, adverse biological effects. Developing Xenopus laevis tadpoles of two age classes were exposed to the PCB mixture Aroclor 1254 for 2 days. Real-time PCR was used to quantitate mRNA expression for 11 physiologically relevant, potential bioindicator genes. Younger tadpoles (5 days postfertilization) were resistant to Aroclor 1254 and showed few changes in gross morphology, swimming behavior, survival, or gene expression. Older tadpoles (11 days postfertilization) were more susceptible to Aroclor 1254. Exposure to 25 and 50 ppm Aroclor 1254 caused alterations in gross morphology and swimming behavior and statistically significant decreases in survival. These tadpoles showed statistically significant decreases in gene expression for 9 out of the 11 genes measured. Tadpoles exposed to 10 ppm showed incipient health changes but had gene expression profiles similar to the tadpoles treated with higher doses of Aroclor 1254. Tadpoles exposed to 1 ppm did not exhibit any observable adverse health effects, yet statistically significant decreases in gene expression occurred in these tadpoles (4 out of 11 genes). After prolonged exposure, tadpoles exposed to 1 and 10 ppm Aroclor 1254 exhibited health effects similar to those exposed to higher concentrations. Therefore, changes in expression of specific genes may serve not only as molecular bioindicators of Aroclor 1254 exposure but also as predictors of impending adverse health effects. Environ. Mol. Mutagen. 40:24,35, 2002. © 2002 Wiley-Liss, Inc. [source] Persistent or not persistent?ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2009Polychlorinated biphenyls are readily depurated by grizzly bears (Ursus arctos horribilis) Abstract Major pharmacokinetic processes influencing polychlorinated biphenyl (PCB) accumulation in mammals include uptake, biotransformation, respiration, and excretion. We characterized some of the factors underlying PCB accumulation/loss by evaluating PCB concentrations and patterns in pre- and posthibernation grizzly bears (Ursus arctos horribilis) and their prey. The PCB congeners with vicinal meta - and para -chlorine unsubstituted hydrogen positions consistently showed loss both before and during hibernation, supporting the idea of a dominant role for biotransformation. Retention of all other studied congeners relative to that of PCB 194 varied widely (from <1 to 100%) and was highly correlated with log octanol--water partition coefficient (p < 0.0001). A lack of loss for most of these other congeners during hibernation supports the notion that excretion (e.g., fecal or urinary) or lack of uptake during the feeding season underlies their lack of accumulation, because hibernating bears do not eat or excrete. We estimate that grizzly bears retain less than 10% of total PCBs taken up from their diet. Our results suggest that for grizzly bears, depuration of PCBs via biotransformation is important (explaining ,40% of loss), but that nonbiotransformation processes, such as excretion, may be more important (explaining ,60% of loss). These findings, together with the approximately 91% loss of the persistent PCB 153 congener relative to PCB 194 in grizzly bears, raise important questions about how one defines persistence of PCBs in wildlife and may have bearing on the interpretation of food-web biomagnification studies. [source] Disposition of perfluorinated acid isomers in sprague-dawley rats; Part 2: Subchronic doseENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2009Amila O. De Silva Abstract Two major industrial synthetic pathways have been used to produce perfluorinated acids (PFAs) or their precursors: Telomerization and electrochemical fluorination (ECF). Products of telomer and ECF origin can be distinguished by structural isomer profiles. A mixture of linear and branched perfluoroalkyl isomers is associated with ECF. Telomer products characteristically consist of a single perfluoroalkyl geometry, typically linear. In biota, it is unclear if the isomer profile is conserved relative to the exposure medium and hence whether PFA isomer profiles in organisms are useful for distinguishing environmental PFA sources. A companion study suggested isomer-specific disposition following a single oral gavage exposure to rats. To confirm these findings under a more realistic subchronic feeding scenario, male and female rats were administered PFA isomers by diet for 12 weeks, followed by a 12-week depuration period. The diet contained 500 ng/g each of ECF perfluorooctanoate (PFOA, ,80% n -PFOA), ECF perfluorooctane sulfonate (PFOS, ,70% n -PFOS), and linear and isopropyl perfluorononanoate (n - and iso -PFNA). Blood sampling during the exposure phase revealed preferential accumulation of n -PFOA and n -PFNA compared to most branched isomers. Female rats depurated all isomers faster than males. Both sexes eliminated most branched perfluorocarboxylate isomers more rapidly than the n -isomer. Elimination rates of the major branched PFOS isomers were not statistically different from n -PFOS. Two minor isomers of ECF PFOA and one branched PFOS isomer had longer elimination half-lives than the n-isomers. Although extrapolation of these pharmacokinetics trends in rats to humans and wildlife requires careful consideration of dosage level and species-specific physiology, cumulative evidence suggests that perfluorocarboxylate isomer profiles in biota may not be suitable for quantifying the relative contributions of telomer and ECF sources. [source] Dietary accumulation, disposition, and metabolism of technical pentabrominated diphenyl ether (DE-71) in pregnant mink (Mustela vison) and their offspring,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2008Si Zhang Abstract Concentrations of polybrominated diphenyl ethers (PBDEs) in humans and wildlife suggest significant bioaccumulation potential in mammals, but no quantitative biomagnification data from controlled experiments are currently available. As part of a larger study examining the effects of PBDEs on mink (Mustela vison) reproduction and development, we examined congener-specific tissue distribution, maternal transfer, biotransformation, and biomagnification of the technical penta-BDE mixture, DE-71, in farmed mink. Adult female mink were fed one of four concentrations of DE-71 (0-2.5 ,g/g) in the diet from breeding through gestation and until weaning at 6 weeks postparturition. Parent PBDEs were measured in tissues and excreta of adult mink, kits, and juveniles, whereas hydroxylated PBDEs (OH-PBDEs) were measured in juveniles only. Similar lipid-normalized concentrations of PBDEs were detected in most tissues of adult mink with the exception of brain, in which concentrations were significantly lower. Kits, however, had a higher proportion of PBDEs in brain compared with adults, presumably because of incomplete development of the blood-brain barrier. Maternal transfer favored lower-brominated PBDE congeners, and the bulk of the body burden in kits at weaning resulted from lactational rather than transplacental transfer. Lipid-normalized, whole-body biomagnification factors ranged from 0.5 to 5.2 for the major congeners and were highest for BDEs 47 and 153. Metabolism clearly limited the biomagnification of some PBDEs, and OH-PBDEs were detectable in plasma, liver, and feces. On a mass basis, OH-PBDEs accounted for 28 to 32% of the excreted fraction, indicating metabolism was an important elimination pathway. Further studies are required to understand the mechanisms of PBDE biotransformation. [source] Effects of brominated flame retardants and brominated dioxins on steroidogenesis in H295R human adrenocortical carcinoma cell lineENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2007Ling Ding Abstract Brominated flame retardants (BFRs) and brominated dioxins are emerging persistent organic pollutants that are ubiquitous in the environment and can be accumulated by wildlife and humans. These chemicals can disturb endocrine function. Recent studies have demonstrated that one of the mechanisms of endocrine disruption by chemicals is modulation of steroidogenic gene expression or enzyme activities. In this study, an in vitro assay based on the H295R human adrenocortical carcinoma cell line, which possesses most key genes or enzymes involved in steroidogenesis, was used to examine the effects of five bromophenols, two polybrominated biphenyls (PBBs 77 and 169), 2,3,7,8-tetrabromodibenzo- p -dioxin, and 2,3,7,8-tetrabromodibenzofuran on the expression of 10 key steroidogenic genes. The H295R cells were exposed to various BFR concentrations for 48 h, and the expression of specific genes,cytochrome P450 (CYP11A, CYP11B2, CYP17, CYP19, and CYP21), 3,-hydroxysteroid dehydrogenase (3,HSD2), 17,-hydroxysteroid dehydrogenase (17,HSD1 and 17,HSD4), steroidogenic acute regulatory protein (StAR), and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR),was quantitatively measured using real-time polymerase chain reaction. Cell viability was not affected at the doses tested. Most of the genes were either up- or down-regulated, to some extent, by BFR exposure. Among the genes tested, 3,HSD2 was the most markedly up-regulated, with a range of magnitude from 1.6- to 20-fold. The results demonstrate that bromophenol, bromobiphenyls, and bromodibenzo- p -dioxin/furan are able to modulate steroidogenic gene expression, which may lead to endocrine disruption. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||