Conservation Status (conservation + status)

Distribution by Scientific Domains
Distribution within Life Sciences


Selected Abstracts


Conservation Status as a Biodiversity Trend Indicator: Recommendations from a Decade of Listing Species at Risk in British Columbia

CONSERVATION BIOLOGY, Issue 4 2005
JAMES F. QUAYLE
especies amenazadas; especies en peligro; estado del ambiente Abstract:,Species conservation status is commonly used as a broad-scale indicator of the state of biological diversity. To learn about its value for tracking trends, we examined provincial lists of terrestrial vertebrate species and subspecies at risk in British Columbia, Canada, for 1992 and 2002 to see whether changes in these lists reflected changes in the status of the taxa they represent. Examination of the case histories of individual species and subspecies showed that 65% of additions and deletions to the British Columbia Red List were the result of improvement in knowledge of species status, changes in assessment procedures, and refinements in taxonomy rather than actual changes in a species' status. Comparison to an alternate set of rank scores provided by NatureServe for taxa that appeared on both 1992 and 2002 British Columbia Red Lists revealed changes in status that were not reflected by movement from the list. Estimates of historical conservation status for species on the 1992 British Columbia Red List demonstrated ambiguity around the natural baseline with regard to tracking changes in list composition over time. We discourage the continued use of indicators based solely on conservation status as a means of tracking biodiversity. Instead we recommend advancing strategic indicators around species at risk based on long-term monitoring data, deliberate and explicitly stated baselines, and consistent methods of conservation ranking. Resumen:,El estatus de conservación de las especies comúnmente es utilizado como un indicador de escala amplia del estado de la diversidad biológica. En un esfuerzo por aprender sobre su valor para el seguimiento de tendencias, examinamos listas provinciales, para 1992 y 2002, de especies y subespecies de vertebrados terrestres en riesgo en Columbia Británica, Canadá, para ver si los cambios en estas listas reflejaban cambios en el estatus de los taxa que representan. El examen de la historia del caso de especies y subespecies individuales mostró que 65% de las adiciones y supresiones en la Lista Roja de Columbia Británica fueron el resultado de avances en el conocimiento del estatus de la especie, de cambios en los procedimientos de evaluación y de refinamientos en la taxonomía y no de cambios en el estatus de una especie. La comparación con un conjunto alternativo de valores de clasificación proporcionado por NatureServe para taxa que aparecieron tanto en la Lista Roja de Columbia Británica de 1992 como de 2002 reveló cambios en el estatus que no se reflejaron en movimientos en la lista. Estimaciones del estatus de conservación histórico de especies en la Lista Roja de Columbia Británica de 1992 demostraron ambigüedad alrededor de la línea de base natural en relación con el seguimiento de cambios en el tiempo en la composición de la lista. Desalentamos el uso continuo de indicadores basados solamente en el estatus de conservación como un medio para el seguimiento de biodiversidad. En cambio, recomendamos avanzar con indicadores estratégicos en torno a especies en riesgo con base en datos de monitoreo de largo plazo, en líneas básicas puestas de manifiesto deliberada y explícitamente y en métodos consistentes para la clasificación de la conservación. [source]


Conservation status and causes of decline of the threatened New Zealand Long-tailed Bat Chalinolobus tuberculatus (Chiroptera: Vespertilionidae)

MAMMAL REVIEW, Issue 2 2000
Colin F. J. O'Donnell
ABSTRACT Historical anecdotes and preliminary monitoring since 1990 indicate that New Zealand Long-tailed Bats (Chalinolobus tuberculatus, Vespertilionidae) are now rare or absent at many sites where formerly they were common. Chalinolobus tuberculatus appeared to be common throughout New Zealand in the 1800s but by 1900,30 it was becoming scarce in many districts. Formal surveys in the South Island since 1990 either failed to find C. tuberculatus, or recorded bats in low numbers. Of eight sites where transect counts were undertaken, bats were recorded frequently at two sites (45,66% of counts; Eglinton and Dart Valleys), rarely at four sites (2.4,10.7% of counts), and were not recorded at the remaining two sites despite considerable survey effort. Of 10 sites where stationary counts using automatic detector units were used, no C. tuberculatus were recorded in three areas (153 nights combined), they were found rarely at six sites (2.1,21.0% of nights; 461 nights combined) and were recorded commonly only in the Eglinton Valley (85% of 120 nights). Assertions that C. tuberculatus are ,common' and that the conservation status is ,secure' are questionable and this review supports suggestions that the species should be classed as ,Vulnerable'. Possible causes of decline have been suggested including clearance and logging of lowland forests, predation by introduced mammals and owls, competition for roost sites by introduced mammals, birds and wasps, and human interference and disturbance at roosting sites. However, authors' claims have all been speculative and unsubstantiated. There has been no research undertaken to quantify these claims, and this is required urgently. The results of these preliminary surveys provide a new baseline against which future population trends might be compared. Increased effort using standardized monitoring techniques, applied at a national level, is required to confirm the possible trends and to help identify the best sites where conservation managers may attempt to restore the population level. [source]


What are we saving?

ANIMAL CONSERVATION, Issue 3 2009
Developing a standardized approach for conservation action
Abstract Are all species equal in terms of conservation attention? We developed a novel framework to assess the level of conservation attention given to 697 threatened mammals and 100 critically endangered amphibian species. Our index of conservation attention provides a quantitative framework for assessing how conservation resources are allocated, based on the degree to which conservation interventions have been proposed and implemented. Our results provide evidence of the strong biases in global conservation attention. We find that most threatened species receive little or no conservation, and that the small number receiving substantial attention is extremely biased. Species most likely to receive conservation attention are those which are well-studied, charismatic and that live in the developed world. Conservation status and evolutionary distinctiveness appear to have little importance in conservation decision-making at the global scale. Most species inhabit the tropics and are both poorly known and uncharismatic. Therefore, the majority of biodiversity is being ignored by current conservation action. [source]


The Need to Rationalize and Prioritize Threatening Processes Used to Determine Threat Status in the IUCN Red List

CONSERVATION BIOLOGY, Issue 6 2009
MATT W. HAYWARD
carnivora; competencia; estatus de conservación; procesos amenazantes Abstract:,Thorough evaluation has made the International Union for Conservation of Nature (IUCN) Red List the most widely used and accepted authority on the conservation status of biodiversity. Although the system used to determine risk of extinction is rigorously and objectively applied, the list of threatening processes affecting a species is far more subjectively determined and has not had adequate review. I reviewed the threats listed in the IUCN Red List for randomly selected groups within the three most threatened orders of mammals: Artiodactyla, Carnivora, and Primates. These groups are taxonomically related and often ecologically similar, so I expected they would suffer relatively similar threats. Hominoid primates and all other terrestrial fauna faced similar threats, except for bovine artiodactyls and large, predatory carnivores, which faced significantly different threats. Although the status of bovines and hominoids and the number of threats affecting them were correlated, this was not the case for large carnivores. Most notable, however, was the great variation in the threats affecting individual members of each group. For example, the endangered European bison (Bison bonasus) has no threatening processes listed for it, and the lion (Panthera leo) is the only large predator listed as threatened with extinction by civil war. Some threatening processes appear spurious for the conservation of the species, whereas other seemingly important factors are not recorded as threats. The subjective nature of listing threatening processes, via expert opinion, results in substantial biases that may be allayed by independent peer review, use of technical manuals, consensus among multiple assessors, incorporation of probability modeling via decision-tree analysis, and adequate coordination among evaluators. The primary focus should be on species-level threats rather than population-level threats because the IUCN Red List is a global assessment and smaller-scale threats are more appropriate for national status assessments. Until conservationists agree on the threats affecting species and their relative importance, conservation action and success will be hampered by scattering scarce resources too widely and often by implementing conflicting strategies. Resumen:,La evaluación exhaustiva ha hecho que la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (UICN) sea la autoridad más aceptada y ampliamente utilizada respecto al estatus de conservación de la biodiversidad. Aunque el sistema utilizado para determinar el riesgo de extinción es aplicado rigurosa y objetivamente, la lista de procesos amenazantes que afectan a las especies es determinado muy subjetivamente y no es revisado adecuadamente. Revisé las amenazas consideradas en la Lista Roja UICN para grupos seleccionados aleatoriamente en los tres órdenes de mamíferos más amenazados: Artyodactila, Carnivora y Primates. Estos grupos están relacionados taxonómicamente y a menudo son ecológicamente similares, así que esperaba que tuvieran amenazas relativamente similares. Los primates homínidos y toda la demás fauna terrestre enfrentan amenazas similares, excepto por los bovinos artiodáctilos y los carnívoros depredadores mayores, que enfrentan amenazas significativamente diferentes. Aunque el estatus de los bovinos y homínidos y el número de amenazas que los afectan estuvieron correlacionados, este no fue el caso para los carnívoros mayores. Sin embargo, lo más notable fue la gran variación en las amenazas que afectan a miembros individuales de cada grupo. Por ejemplo, no hay procesos amenazantes enlistados para el bisonte europeo (Bison bonasus), y el león (Panthera leo) es el único depredador mayor enlistado como amenazado de extinción por la guerra civil. Algunos procesos amenazantes parecen espurios para la conservación de las especies, mientras que otros factores aparentemente importantes no están registrados como amenazas. La naturaleza subjetiva de los procesos de enlistado, por medio de la opinión de expertos, resulta en sesgos sustanciales que pueden disiparse por la revisión independiente por pares, el uso de manuales técnicos, el consenso de múltiples asesores, la incorporación del modelado probabilístico mediante análisis de árboles de decisión y la adecuada coordinación entre evaluadores. El enfoque principal debería ser sobre amenazas a nivel de especies en lugar de amenazas a nivel de poblaciones porque la Lista Roja UICN es una evaluación global y las amenazas a menor escala son más apropiadas para evaluaciones nacionales de estatus. Hasta que los conservacionistas estén de acuerdo sobre las amenazas que afectan a las especies y su importancia relativa, las acciones de conservación y su éxito estarán obstaculizados por la dispersión demasiado amplia de recursos limitados y a menudo por la implementación de estrategias contrapuestas. [source]


Quantification of Extinction Risk: IUCN's System for Classifying Threatened Species

CONSERVATION BIOLOGY, Issue 6 2008
GEORGINA M. MACE
definición de prioridades de conservación; especies amenazadas; Lista Roja UICN; riesgo de extinción Abstract:,The International Union for Conservation of Nature (IUCN) Red List of Threatened Species was increasingly used during the 1980s to assess the conservation status of species for policy and planning purposes. This use stimulated the development of a new set of quantitative criteria for listing species in the categories of threat: critically endangered, endangered, and vulnerable. These criteria, which were intended to be applicable to all species except microorganisms, were part of a broader system for classifying threatened species and were fully implemented by IUCN in 2000. The system and the criteria have been widely used by conservation practitioners and scientists and now underpin one indicator being used to assess the Convention on Biological Diversity 2010 biodiversity target. We describe the process and the technical background to the IUCN Red List system. The criteria refer to fundamental biological processes underlying population decline and extinction. But given major differences between species, the threatening processes affecting them, and the paucity of knowledge relating to most species, the IUCN system had to be both broad and flexible to be applicable to the majority of described species. The system was designed to measure the symptoms of extinction risk, and uses 5 independent criteria relating to aspects of population loss and decline of range size. A species is assigned to a threat category if it meets the quantitative threshold for at least one criterion. The criteria and the accompanying rules and guidelines used by IUCN are intended to increase the consistency, transparency, and validity of its categorization system, but it necessitates some compromises that affect the applicability of the system and the species lists that result. In particular, choices were made over the assessment of uncertainty, poorly known species, depleted species, population decline, restricted ranges, and rarity; all of these affect the way red lists should be viewed and used. Processes related to priority setting and the development of national red lists need to take account of some assumptions in the formulation of the criteria. Resumen:,La Lista Roja de Especies Amenazadas de la UICN (Unión Internacional para la Conservación de la Naturaleza) fue muy utilizada durante la década de l980 para evaluar el estatus de conservación de especies para fines políticos y de planificación. Este uso estimuló el desarrollo de un conjunto nuevo de criterios cuantitativos para enlistar especies en las categorías de amenaza: en peligro crítico, en peligro y vulnerable. Estos criterios, que se pretendía fueran aplicables a todas las especies excepto microorganismos, eran parte de un sistema general para clasificar especies amenazadas y fueron implementadas completamente por la UICN en 2000. El sistema y los criterios han sido ampliamente utilizados por practicantes y científicos de la conservación y actualmente apuntalan un indicador utilizado para evaluar el objetivo al 2010 de la Convención de Diversidad Biológica. Describimos el proceso y el respaldo técnico del sistema de la Lista Roja de la IUCN. Los criterios se refieren a los procesos biológicos fundamentales que subyacen en la declinación y extinción de una población. Pero, debido a diferencias mayores entre especies, los procesos de amenaza que los afectan y la escasez de conocimiento sobre la mayoría de las especies, el sistema de la UICN tenía que ser amplio y flexible para ser aplicable a la mayoría de las especies descritas. El sistema fue diseñado para medir los síntomas del riesgo de extinción, y utiliza cinco criterios independientes que relacionan aspectos de la pérdida poblacional y la declinación del rango de distribución. Una especie es asignada a una categoría de amenaza si cumple el umbral cuantitativo por lo menos para un criterio. Los criterios, las reglas acompañantes y las directrices utilizadas por la UICN tienen la intención de incrementar la consistencia, transparencia y validez de su sistema de clasificación, pero requiere algunos compromisos que afectan la aplicabilidad del sistema y las listas de especies que resultan. En particular, se hicieron selecciones por encima de la evaluación de incertidumbre, especies poco conocidas, especies disminuidas, declinación poblacional, rangos restringidos y rareza; todas estas afectan la forma en que las listas rojas deberían ser vistas y usadas. Los procesos relacionados con la definición de prioridades y el desarrollo de las listas rojas nacionales necesitan considerar algunos de los supuestos en la formulación de los criterios. [source]


Conservation Status as a Biodiversity Trend Indicator: Recommendations from a Decade of Listing Species at Risk in British Columbia

CONSERVATION BIOLOGY, Issue 4 2005
JAMES F. QUAYLE
especies amenazadas; especies en peligro; estado del ambiente Abstract:,Species conservation status is commonly used as a broad-scale indicator of the state of biological diversity. To learn about its value for tracking trends, we examined provincial lists of terrestrial vertebrate species and subspecies at risk in British Columbia, Canada, for 1992 and 2002 to see whether changes in these lists reflected changes in the status of the taxa they represent. Examination of the case histories of individual species and subspecies showed that 65% of additions and deletions to the British Columbia Red List were the result of improvement in knowledge of species status, changes in assessment procedures, and refinements in taxonomy rather than actual changes in a species' status. Comparison to an alternate set of rank scores provided by NatureServe for taxa that appeared on both 1992 and 2002 British Columbia Red Lists revealed changes in status that were not reflected by movement from the list. Estimates of historical conservation status for species on the 1992 British Columbia Red List demonstrated ambiguity around the natural baseline with regard to tracking changes in list composition over time. We discourage the continued use of indicators based solely on conservation status as a means of tracking biodiversity. Instead we recommend advancing strategic indicators around species at risk based on long-term monitoring data, deliberate and explicitly stated baselines, and consistent methods of conservation ranking. Resumen:,El estatus de conservación de las especies comúnmente es utilizado como un indicador de escala amplia del estado de la diversidad biológica. En un esfuerzo por aprender sobre su valor para el seguimiento de tendencias, examinamos listas provinciales, para 1992 y 2002, de especies y subespecies de vertebrados terrestres en riesgo en Columbia Británica, Canadá, para ver si los cambios en estas listas reflejaban cambios en el estatus de los taxa que representan. El examen de la historia del caso de especies y subespecies individuales mostró que 65% de las adiciones y supresiones en la Lista Roja de Columbia Británica fueron el resultado de avances en el conocimiento del estatus de la especie, de cambios en los procedimientos de evaluación y de refinamientos en la taxonomía y no de cambios en el estatus de una especie. La comparación con un conjunto alternativo de valores de clasificación proporcionado por NatureServe para taxa que aparecieron tanto en la Lista Roja de Columbia Británica de 1992 como de 2002 reveló cambios en el estatus que no se reflejaron en movimientos en la lista. Estimaciones del estatus de conservación histórico de especies en la Lista Roja de Columbia Británica de 1992 demostraron ambigüedad alrededor de la línea de base natural en relación con el seguimiento de cambios en el tiempo en la composición de la lista. Desalentamos el uso continuo de indicadores basados solamente en el estatus de conservación como un medio para el seguimiento de biodiversidad. En cambio, recomendamos avanzar con indicadores estratégicos en torno a especies en riesgo con base en datos de monitoreo de largo plazo, en líneas básicas puestas de manifiesto deliberada y explícitamente y en métodos consistentes para la clasificación de la conservación. [source]


From Red Lists to Species of Conservation Concern

CONSERVATION BIOLOGY, Issue 6 2004
VERENA KELLER
aves; conservación de especies; listas rojas; prioridades de conservación; Suiza Abstract:,National red lists of threatened animal and plant species prepared according to the criteria of the World Conservation Union (IUCN) adequately reflect the extinction risk of species within a country but cannot be used directly to set conservation priorities. In particular, the significance of national populations for the conservation of the species as a whole is not taken into account. We present a procedure that can be used to assess national responsibility based on the national red-list status of a species, the international importance of the national population, and the species' "historical rarity" status. We distinguished five responsibility classes for breeding birds: B1, threatened species with internationally important populations in Switzerland; B2, threatened species with internationally less important populations; B3, nonthreatened species with internationally important populations; B4, nonthreatened species with internationally less important populations; and B5, species that have never been common in Switzerland. Two responsibility classes were distinguished for birds occurring in Switzerland as visitors: G1, species with large concentrations in Switzerland and an unfavorable conservation status in Europe, and G2, species with large concentrations in Switzerland and a favorable conservation status in Europe. Two additional classes (G3 and G4) for visiting species occurring in internationally less important numbers are possible but were not analyzed in detail. Responsibility classes B1, B2, B3, G1, and G2 were defined as species of national conservation concern. We developed the method for birds in Switzerland, but it can be used in other countries and for other taxonomic groups as well. It is particularly suitable where national red lists are established according to IUCN guidelines. Resumen:,Las listas rojas nacionales de especies de animales y plantas amenazadas que siguen los criterios de la World Conservation Union (IUCN) reflejan adecuadamente el riesgo de extinción de especies en un país pero no pueden ser utilizadas directamente para definir prioridades de conservación. En particular, no se toma en cuenta el significado de poblaciones nacionales para la conservación de especies como tales. Presentamos un procedimiento que se puede utilizar para evaluar la responsabilidad nacional con base en el estatus de lista roja de una especie en un país, la importancia internacional de la población nacional y el estatus de "rareza histórica" de la especie. Distinguimos cinco clases de responsabilidad para aves residentes: B1, especies amenazadas con poblaciones internacionalmente importantes en Suiza; B2, especies amenazadas con poblaciones internacionalmente menos importantes; B3, especies no amenazadas con poblaciones internacionalmente importantes; B4, especies no amenazadas con poblaciones internacionalmente menos importantes; y B5, especies que nunca han sido comunes en Suiza. Se distinguieron dos clases de responsabilidad para aves que ocurren como visitantes en Suiza: G1, especies con grandes concentraciones en Suiza y un estatus de conservación desfavorable en Europa y G2, especies con grandes concentraciones en Suiza y un estatus de conservación favorable en Europa. Son posibles dos clases más, (G3 y G4) para especies visitantes que ocurren en números menos importantes internacionalmente, pero no fueron analizados en detalle. Las clases de responsabilidad B1, B2, B3, G1 y G2 fueron definidas como especies de interés nacional para la conservación. Desarrollamos el método para aves en Suiza, pero también se puede utilizar en otros países y con otros grupos taxonómicos, Es particularmente adecuado donde las listas rojas nacionales se establecen de acuerdo con lineamientos de IUCN. [source]


Extinction-Rate Estimates for a Modern Neotropical Flora

CONSERVATION BIOLOGY, Issue 5 2002
Nigel C. A. Pitman
We present the first quantitative estimates of extinction rate in a complete Neotropical flora based on historical plant-collection records, quantitative measurements of forest loss and plant diversity, and the conservation status of endemic plant species in Ecuador. Our analyses suggest that 19,46 endemic plant species have gone extinct in Ecuador over the last 250 years, mostly because of habitat loss, and therefore are now globally extinct. An additional 282 species, nearly 7% of Ecuador's endemic flora, qualify as critically endangered. We found evidence of impending large-scale plant extinctions in the country's coastal and Andean forests, but little extinction and low potential for extinction in the Amazonian lowlands. Resumen: Las preocupaciones sobre las elevadas tasas de extinción en los trópicos son una característica común en la literatura sobre conservación, pero las mediciones directas son escasas. Presentamos las primeras estimaciones cuantitativas de la tasa de extinción en una flora neotropical completa basada en los expedientes históricos de colecciones de plantas, las mediciones cuantitativas de la pérdida de bosque y de diversidad y el estado de conservación de especies de plantas endémicas en Ecuador. Nuestro análisis sugiere que 19,46 especies de plantas se han extinguido en el Ecuador a lo largo de los últimos 250 años, debido principalmente a la pérdida de hábitat y por lo tanto son ahora extintas a nivel mundial. Además 282 especies, cerca del 7% de la flora endémica del Ecuador califica como críticamente amenazada. Encontramos indicaciones de inminentes extinciones de gran escala en el país, tanto en los bosques costeros como en los bosques de los Andes, pero poca extinción y bajo potencial de extinción en las tierras bajas del Amazonas. [source]


Four Miniature Species of Aloe from Madagascar

CURTIS'S BOTANICAL MAGAZINE, Issue 4 2004
David Du Puy
Summary., The habitats and distribution of four Aloe species from Madagascar are described and illustrated, and their conservation status is discussed. [source]


Ecological niche modelling as a technique for assessing threats and setting conservation priorities for Asian slow lorises (Primates: Nycticebus)

DIVERSITY AND DISTRIBUTIONS, Issue 2 2009
J. S. Thorn
ABSTRACT Aim, Data on geographical ranges are essential when defining the conservation status of a species, and in evaluating levels of human disturbance. Where locality data are deficient, presence-only ecological niche modelling (ENM) can provide insights into a species' potential distribution, and can aid in conservation planning. Presence-only ENM is especially important for rare, cryptic and nocturnal species, where absence is difficult to define. Here we applied ENM to carry out an anthropogenic risk assessment and set conservation priorities for three threatened species of Asian slow loris (Primates: Nycticebus). Location, Borneo, Java and Sumatra, Southeast Asia. Methods, Distribution models were built using maximum entropy (MaxEnt) ENM. We input 20 environmental variables comprising temperature, precipitation and altitude, along with species locality data. We clipped predicted distributions to forest cover and altitudinal data to generate remnant distributions. These were then applied to protected area (PA) and human land-use data, using specific criteria to define low-, medium- or high-risk areas. These data were analysed to pinpoint priority study sites, suitable reintroduction zones and protected area extensions. Results, A jackknife validation method indicated highly significant models for all three species with small sample sizes (n = 10 to 23 occurrences). The distribution models represented high habitat suitability within each species' geographical range. High-risk areas were most prevalent for the Javan slow loris (Nycticebus javanicus) on Java, with the highest proportion of low-risk areas for the Bornean slow loris (N. menagensis) on Borneo. Eighteen PA extensions and 23 priority survey sites were identified across the study region. Main conclusions, Discriminating areas of high habitat suitability lays the foundations for planning field studies and conservation initiatives. This study highlights potential reintroduction zones that will minimize anthropogenic threats to animals that are released. These data reiterate the conclusion of previous research, showing MaxEnt is a viable technique for modelling species distributions with small sample sizes. [source]


Diversity, distinctiveness and conservation status of the Mediterranean coastal dung beetle assemblage in the Regional Natural Park of the Camargue (France)

DIVERSITY AND DISTRIBUTIONS, Issue 6 2001
Jorge Miguel Lobo
Abstract. The Mediterranean region as a whole has the highest dung beetle species richness within Europe. Natural coastal habitats in this region are among those which have suffered severe human disturbance. We studied dung beetle diversity and distinctiveness within one of the most important coastal protected areas in the west Euro-Mediterranean region (the regional Park of Camargue, southern France) and made comparisons of dung beetle assemblages with other nearby Mediterranean localities, as well as with other coastal protected area (Doñana National Park, Spain). Our finding showed that: (1) The species richness of coastal habitats in the Camargue is low and only grasslands showed a similar level of species richness and abundance to inland habitats of other Mediterranean localities. The unique habitats of the coastal area (beaches, dunes and marshes) are largely colonized by species widely distributed in the hinterland. (2) In spite of their low general distinctiveness, dune and marsh edges are characterized by the occurrence of two rare, vulnerable, specialized and large roller dung beetle species of the genus Scarabaeus. As with other Mediterranean localities, current findings suggest a recent decline of Scarabaeus populations and the general loss of coastal dung beetle communities in Camargue. (3) The comparison of dung beetle assemblages between the Camargue and Doñana shows that, in spite of the low local dung beetle species richness in the Camargue, the regional dung beetle diversity is similar between both protected areas. Unique historical and geographical factors can explain the convergence in regional diversity as well as the striking divergence in the composition of dung beetle assemblages between both territories. [source]


Effects of species' ecology on the accuracy of distribution models

ECOGRAPHY, Issue 1 2007
Jana M. McPherson
In the face of accelerating biodiversity loss and limited data, species distribution models , which statistically capture and predict species' occurrences based on environmental correlates , are increasingly used to inform conservation strategies. Additionally, distribution models and their fit provide insights on the broad-scale environmental niche of species. To investigate whether the performance of such models varies with species' ecological characteristics, we examined distribution models for 1329 bird species in southern and eastern Africa. The models were constructed at two spatial resolutions with both logistic and autologistic regression. Satellite-derived environmental indices served as predictors, and model accuracy was assessed with three metrics: sensitivity, specificity and the area under the curve (AUC) of receiver operating characteristics plots. We then determined the relationship between each measure of accuracy and ten ecological species characteristics using generalised linear models. Among the ecological traits tested, species' range size, migratory status, affinity for wetlands and endemism proved most influential on the performance of distribution models. The number of habitat types frequented (habitat tolerance), trophic rank, body mass, preferred habitat structure and association with sub-resolution habitats also showed some effect. In contrast, conservation status made no significant impact. These findings did not differ from one spatial resolution to the next. Our analyses thus provide conservation scientists and resource managers with a rule of thumb that helps distinguish, on the basis of ecological traits, between species whose occurrence is reliably or less reliably predicted by distribution models. Reasonably accurate distribution models should, however, be attainable for most species, because the influence ecological traits bore on model performance was only limited. These results suggest that none of the ecological traits tested provides an obvious correlate for environmental niche breadth or intra-specific niche differentiation. [source]


Host plants and butterfly biology.

ECOLOGICAL ENTOMOLOGY, Issue 1 2004
Do host-plant strategies drive butterfly status?
Abstract., 1.,To determine whether rarity and decline is linked to organism ecology, associations have been examined between butterfly larval host-plant competitive, stress-tolerant, ruderal (C-S-R) strategies and butterfly biology. 2.,Associations have been sought between mean C-S-R scores for larval host plants with butterfly life history, morphology and physiology variables, resource use, population attributes, geography, and conservation status. Comparisons are carried out across species and controlled for phylogenetic patterning. 3.,Butterfly biology is linked to host-plant strategies. An increasing tendency of a butterfly's host plants to a particular strategy biases that butterfly species to functionally linked life-history attributes and resource breadth and type. In turn, population attributes and geography are significantly and substantially affected by host choice and the strategies of these host plants. 4.,The greatest contrast is between butterfly species whose host plants are labelled C and R strategists and those whose host plants are labelled S strategists. Increasingly high host-plant C and R strategy scores bias butterflies to rapid development, short early stages, multivoltinism, long flight periods, early seasonal emergence, higher mobility, polyphagy, wide resource availability and biotope occupancy, open, areally expansive, patchy population structures, denser distributions, wider geographical ranges, resistance to range retractions as well as to increasing rarity in the face of environmental changes. Increasing host-plant S strategy scores have reversed tendencies, biasing those butterfly species to extended development times, fewer broods, short flight periods, smaller wing expanse and lower mobility, monophagy, restricted resource exploitation and biotope occupancy, closed, areally limited populations with typical metapopulation structures, sparse distributions, and limited geographical ranges, range retractions, and increased rarity. 5.,Species with S strategy host plants are species vulnerable to current environmental changes and species of conservation concern. [source]


Mass regulation in response to predation risk can indicate population declines

ECOLOGY LETTERS, Issue 10 2007
Ross MacLeod
Abstract In theory, survival rates and consequent population status might be predictable from instantaneous behavioural measures of how animals prioritize foraging vs. avoiding predation. We show, for the 30 most common small bird species ringed in the UK, that one quarter respond to higher predation risk as if it is mass-dependent and lose mass. Half respond to predation risk as if it only interrupts their foraging and gain mass thus avoiding consequent increased starvation risk from reduced foraging time. These mass responses to higher predation risk are correlated with population and conservation status both within and between species (and independently of foraging habitat, foraging guild, sociality index and size) over the last 30 years in Britain, with mass loss being associated with declining populations and mass gain with increasing populations. If individuals show an interrupted foraging response to higher predation risk, they are likely to be experiencing a high quality foraging environment that should lead to higher survival. Whereas individuals that show a mass-dependent foraging response are likely to be in lower quality foraging environments, leading to relatively lower survival. [source]


Rediscoveries in Eriocaulaceae: seven narrowly distributed taxa from the Espinhaço Range in Minas Gerais, Brazil

FEDDES REPERTORIUM, Issue 3-4 2010
Livia Echternacht
Abstract We report the rediscovery of seven Eriocaulaceae taxa, which were known exclusively from the type collection or from historic collections. The taxa are Actinocephalus cipoensis, Actinocephalus coutoensis, Actinocephalus ithyphyllus, Paepalanthus argenteus var. elatus, Paepalanthus decussus, Paepalanthus stuetzelii, and Syngonanthus circinnatus, all narrowly distributed. They occur in the southern and central part of the Espinhaço Range in Minas Gerais, Brazil. We provide a brief taxonomic comment for each taxon, as well as details about the populations, habitat, and a revised IUCN conservation status. Finally, we discuss the earlier and present collecting efforts at the visited sites, as well as some conservational aspects (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Using fishers' anecdotes, naturalists' observations and grey literature to reassess marine species at risk: the case of the Gulf grouper in the Gulf of California, Mexico

FISH AND FISHERIES, Issue 2 2005
Andrea Sáenz, Arroyo
Abstract Designing fishing policies without knowledge of past levels of target species abundance is a dangerous omission for fisheries management. However, as fisheries monitoring started long after exploitation of many species began, this is a difficult issue to address. Here we show how the ,shifting baseline' syndrome can affect the stock assessment of a vulnerable species by masking real population trends and thereby put marine animals at serious risk. Current fishery data suggest that landings of the large Gulf grouper (Mycteroperca jordani, Serranidae) are increasing in the Gulf of California. However, reviews of historical evidence, naturalists' observations and a systematic documentation of fishers' perceptions of trends in the abundance of this species indicate that it has dramatically declined. The heyday for the Gulf grouper fishery occurred prior to the 1970s, after which abundance dropped rapidly, probably falling to a few percent of former numbers. This decline happened long before fishery statistics were formally developed. We use the case of the Gulf grouper to illustrate how other vulnerable tropical and semi-tropical fish and shellfish species around the world may be facing the same fate as the Gulf grouper. In accordance with other recent studies, we recommend using historical tools as part of a broad data-gathering approach to assess the conservation status of marine species that are vulnerable to over-exploitation. [source]


Changes in fish assemblages in catchments in north-eastern Spain: biodiversity, conservation status and introduced species

FRESHWATER BIOLOGY, Issue 8 2010
ALBERTO MACEDA-VEIGA
Summary 1. North-eastern Spain is a hot spot for the introduction of alien fish species, and its native fish fauna is one of the most endangered worldwide. We used an extensive data set from 2002 to 2003 and historical information from the area to characterize fish diversity and establish conservation priorities in river catchments. 2. Diversity indices were used to characterize fish diversity at the basin scale. An index of conservation status was applied for each species, which considers the occurrence, abundance and endemicity of each taxon. We used indirect ordination methods to test the relationship among basin features and to identify those variables most correlated with each other. To identify physical, biotic and environmental characteristics that seem to make a basin particularly susceptible to invasion, we performed a step-wise multiple regression to examine the relationship between the number of native, translocated and introduced fish species (including the original native species richness of each basin), and landscape variables. 3. Over a period of approximately 50 years, the mean range size of native fish species has decreased by 60%. The greatest decline occurred in Gasterosteus gymnurus, Anguilla anguilla and Salaria fluviatilis, for which species over 75% of the original distribution area has been lost. The species with the highest conservation index were Gasterosteus gymnurus and Salaria fluviatilis. 4. Basin area and the catchment type explained 70% of variation in native species richness, whereas the number of dams and basin area accounted for more than 80% of variation in the number of introduced species. 5. The original native species richness and the number of introduced species at basin scale were not related, and thus there was no evidence of "biotic resistance" to invasion. The restoration of natural hydrologic processes and the development of specific management tools to protect native species, such as the prioritization of areas for fish conservation and the eradication of local populations of exotic species, are required to restore native fish fauna in these catchments. [source]


Using a 1-D mixing model to assess the potential impact of year-to-year changes in weather on the habitat of vendace (Coregonus albula) in Bassenthwaite Lake, Cumbria

FRESHWATER BIOLOGY, Issue 8 2006
D. G. GEORGE
Summary 1. Bassenthwaite Lake in Cumbria is one of only two English lakes containing a population of vendace (Coregonus albula). The spatial distribution and survival of this fish is strongly influenced by the temperature and oxygen content of the water. In summer, this fish moves into deeper, colder water but avoids areas where the oxygen content is low. 2. In recent years, there has been a dramatic decline in the number of vendace found in the lake, a trend that may have been exacerbated by a succession of warm summers. Bassenthwaite only becomes stably stratified during calm, warm periods when a significant proportion of the deep water becomes anoxic. 3. Here, a one dimensional (1-D) process-based temperature-oxygen model is used to simulate the year-to-year variations in the severity of these ,extreme events'. The model is validated using field measurements acquired in the 1990s and used to predict the range of depths accessible to the vendace. 4. An empirical, weather-driven model is then used to ,hindcast' the mixing characteristics of the lake in the 1980s and estimate the proportion of the habitat lost during warm, calm summers. These simulations show that periods of stable thermal stratification have become increasingly common in recent years. In the 1980s, only one ,extreme event' was identified but four such events were recorded in the 1990s. 5. The results are discussed in relation to the conservation status of the species and the potential effect of climate change on its survival in the English Lake District. [source]


Feature: UNESCO World Heritage and the Joggins cliffs of Nova Scotia

GEOLOGY TODAY, Issue 4 2004
Howard J. Falcon-Lang
UNESCO World Heritage status is the highest honour that may be bestowed on a palaeontological site. In addition to heightening conservation status, it confers international recognition of a locality's ,outstanding universal value' and often triggers the release of substantial regional development funds. Despite these incentives it is, perhaps, not surprising that only a handful of fossil sites have successfully navigated the World Heritage selection process. In this feature, we draw on our recent experience of developing a World Heritage bid for the Pennsylvanian ,Coal Age' locality of Joggins, Nova Scotia. As well as demonstrating the huge significance of Joggins, we hope that our findings will provide valuable guidelines for the assessment of World Heritage fossil sites in general. [source]


Detection of 95 novel mutations in coagulation factor VIII gene F8 responsible for hemophilia A: results from a single institution ,

HUMAN MUTATION, Issue 7 2006
Benoît Guillet
Abstract Hemophilia A (HA) is an X-linked hereditary bleeding disorder defined by a qualitative and/or quantitative factor VIII (FVIII) deficiency. The molecular diagnosis of HA is challenging because of the high number of different causative mutations that are distributed throughout the large F8 gene. The putative role of the novel mutations, especially missense mutations, may be difficult to interpret as causing HA. We identified 95 novel mutations out of 180 different mutations responsible for HA in 515 patients from 406 unrelated families followed up at a single hemophilia treatment center of the Bicêtre university hospital (Assistance Publique-Hôpitaux de Paris [AP-HP], Le Kremlin-Bicêtre). These 95 novel mutations comprised 55 missense mutations, 12 nonsense mutations, 11 splice site mutations, and 17 small insertions/deletions. We therefore developed a mutation analysis based on a body of proof that combines the familial segregation of the mutation, the resulting biological and clinical HA phenotype, and the molecular consequences of the amino acid (AA) substitution. For the latter, we studied the putative biochemical modifications: its conservation status with cross-species FVIII and homologous proteins, its putative location in known FVIII functional regions, and its spatial position in the available FVIII 3D structures. The usefulness of such a strategy in interpreting the causality of novel F8 mutations is emphasized. Hum Mutat 27(7), 676,685, 2006. © 2006 Wiley-Liss, Inc. [source]


Population trends of widespread woodland birds in Europe

IBIS, Issue 2007
RICHARD D. GREGORY
We explore population trends of widespread and common woodland birds using data from an extensive European network of ornithologists for the period 1980,2003. We show considerable differences exist in the European trends of species according to the broad habitat they occupy and the degree to which they specialize in habitat use. On average, common forest birds are in shallow decline at a European scale; common forest birds declined by 13%, and common forest specialists by 18%, from 1980 to 2003. In comparison, populations of common specialists of farmland have declined moderately, falling on average by 28% from 1980 to 2003. These patterns contrast with that shown by generalist species whose populations have been roughly stable over the same period, their overall index increasing by 3%. There was some evidence of regional variation in the population trends of these common forest species. The most obvious pattern was the greater stability of population trends in Eastern Europe compared with other regions considered. Among common forest birds, long-distance migrants and residents have on average declined most strongly, whereas short-distance migrants have been largely stable, or have increased. There was some evidence to suggest that ground- or low-nesting species have declined more strongly on average, as have forest birds with invertebrate diets. Formal analysis of the species trends confirmed the influence of habitat use, habitat specialization and nest-site; the effects of region and migration strategy were less clear-cut. There was also evidence to show that year-to-year variation in individual species trends at a European scale was influenced by cold winter weather in a small number of species. We recommend that the species trend information provided by the new pan-European scheme should be used alongside existing mechanisms to review the conservation status of European birds. The analysis also allows us to reappraise the role of common forest bird populations as a potential barometer of wider forest health. The new indicator appears to be a useful indicator of the state of widespread European forest birds and might prove to be a useful surrogate for trends in forest biodiversity and forest health, but more work is likely to be needed to understand the interaction between bird populations and their drivers in forest. [source]


Culling wildlife hosts to control disease: mountain hares, red grouse and louping ill virus

JOURNAL OF APPLIED ECOLOGY, Issue 4 2010
Annabel Harrison
Summary 1.,Culling wildlife hosts is often implemented as a management technique to control pathogen transmission from wildlife to domestic or other economically important animals. However, culling may have unexpected consequences, can be expensive and may have wider implications for biodiversity and ecosystem functioning. 2.,We assess the evidence that culling mountain hares Lepus timidus is an effective and practical way to control louping ill virus in red grouse Lagopus lagopus scoticus. 3.,Evidence from the available literature is limited, restricting our ability to reliably assess the effectiveness of culling mountain hares to control ticks, louping ill virus, or increase red grouse densities. Furthermore, the information required to assess the cost-benefit of this management strategy is lacking. The population response of mountain hares to culling is not well understood and the possible effects on their conservation status and the upland ecosystem remain unexplored. 4.,We conclude that there is no compelling evidence base to suggest culling mountain hares might increase red grouse densities. 5.,Synthesis and applications. Widespread culling of wildlife is not necessarily effective in reducing disease or improving economic returns. The use of wildlife culls for disease control should be proposed only when: (i) the pathogen transmission cycle is fully understood with all host-vector interactions considered; (ii) the response of wildlife populations to culling is known; and (iii) cost-benefit analysis shows that increased revenue from reduced disease prevalence exceeds the cost of culling. [source]


The sizes of species' geographic ranges

JOURNAL OF APPLIED ECOLOGY, Issue 1 2009
Kevin J. Gaston
Summary 1Geographic range size and how it changes through time is one of the fundamental ecological and evolutionary characteristics of a species, and a strong predictor of extinction risk. However, the measurement of range size remains a substantial challenge. Indeed, there is significant confusion in the literature as to how this should be done, particularly in the context of the distinction between the fundamentally different concepts of extent of occurrence (EOO) and area of occupancy (AOO), and the use of these quantities, including in assessments of the threat status of species. 2Here we review the different approaches to determining the geographic distributions of species, the measurement of their range sizes, the relationships between the two, and other difficulties posed by range size measurement (especially those of range discontinuities when measuring EOO, and spatial scale when measuring AOO). 3We argue that it is important to (i) distinguish the estimation of the distribution of a species from the measurement of its geographic range size; (ii) treat measures of EOO and AOO as serving different purposes, rather than regarding them as more or less accurate ways of measuring range size; and (iii) measure EOO including discontinuities in habitat or occupancy. 4Synthesis and applications. With the availability and collation of extensive data sets on species occurrences, a rapidly increasing number of studies are investigating geographic range size, and particularly how various measures of range size predict macroecological patterns and inform assessments of the conservation status of species and areas. The distinction between EOO and AOO is becoming blurred in many contexts, but most particularly in that of threatened species assessments for Red Listing. Continued progress in these fields demands greater clarity in the meaning and derivation of measures of geographic range size. The two principal measures serve different purposes, and should not be regarded as alternatives that simply differ in accuracy. [source]


Reducing the density of breeding gulls influences the pattern of recruitment of immature Atlantic puffins Fratercula arctica to a breeding colony

JOURNAL OF APPLIED ECOLOGY, Issue 3 2003
S. K. Finney
Summary 1By acting as both competitors and predators, gulls (Larus spp.) are generally considered to reduce significantly the attractiveness of potential breeding sites for other birds. This perceived threat posed by gulls to other breeding birds has led to the implementation of gull control procedures at many seabird colonies. However, the extent to which reducing gull numbers benefits other species has received little rigorous scientific investigation. 2During a gull control programme (1972,89), gull nest density on the Isle of May, south-east Scotland, was reduced by between 30% and 100% in different sections of the island. Following termination of the original programme in 1989, several sections were maintained as gull-free by repeated removal of nests. 3We used data collected over a 23-year period to determine the extent to which the spatial variation in puffin Fratercula arctica recruitment was influenced by changes in the density and spatial distribution of breeding gulls resulting from the control programme. 4The presence of breeding gulls significantly affected the pattern of recruitment of puffins to the colony. Puffin recruitment rate was highest in the sections of the island where gull nest density was low. Gull density explained 21% of the variation in puffin recruitment rate. 5These results suggest that the reduction in the number of breeding gulls substantially increased the attractiveness of areas of the colony as breeding sites for puffins, and is thus likely to have played an important role in the pattern of expansion of the puffin population on the island. 6Synthesis and applications. Following a recent increase in the conservation status of both herring L. argentatus and lesser black-backed gulls L. fuscus, there has been a move to make management decisions more objective. This has highlighted the need for studies such as this, aimed at assessing the impact of gulls and their removal on other breeding birds, to ensure that any future control programmes are both necessary and effective. [source]


Multiple molecular approaches yield no evidence for sex-determining genes in lake sturgeon (Acipenser fulvescens)

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2008
C. R. McCormick
Summary Common DNA-based sexing assays have been widely used for the conservation and management of mammals and birds. However, many fishes do not have genetic sex determination and in those that do, the plasticity of the genes involved means that species-specific assays are normally required. Such DNA-sexing markers would be especially valuable in lake sturgeon (Acipenser fulvescens) because of their sexual monomorphism, delayed sexual maturity, and conservation status. We tried to identify genetic differences between male and female lake sturgeon using several different molecular genetic methods, including randomly amplified polymorphic DNA, representational difference analyses, subtractive hybridization, and a candidate gene approach. Ultimately, a number of genes were identified but none was sex-specific. Although the ultimate mechanism of sex determination is yet unknown, it is possible that sex determination is environmental in lake sturgeon, especially since recent studies have also failed to identify sex determination genes in other sturgeon species. [source]


Identification of Acipenseriformes species in trade

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 2008
A. Ludwig
Summary Sturgeons and paddlefishes (Acipenseridae) are highly endangered freshwater fishes. Their eggs (sold as caviar) are one of the most valuable wildlife products in international trade. Concerns of overharvesting and the conservation status of many of the 27 extant species of Acipenseriformes led to all species being included on the CITES Appendices in 1998. Since then international trade in all products and parts from sturgeon and paddlefish has been regulated. However, despite the controls on trade, unsustainable harvesting continues to threaten many populations. Illegal fishing and trade continues to be a threat to the management of these fish. To enforce the regulation of legal trade and prevention of illegal trade, the development of a uniform identification system for parts and derivates of Acipenseriformes has been identified as an urgent requirement. Ideally this system should be suitable for (i) identification at the species-level of caviar and other products from Acipenseriformes; (ii) population identification; (iii) source identification (wild vs aquaculture); and (iv) determining the age of caviar because strict timeframes govern its international trade. This paper reviews the techniques currently available and their potential to be used in an identification system for Acipenseriformes species and their products in trade. A review of all available identification techniques has shown that there is not a single method that can meet all requirements (see i,iv), and it does not appear to be feasible to develop such a method in the near future therefore the most appropriate methods need to be developed for each. Considering the advantages and disadvantages of all techniques reviewed in this document, the following conclusions can be drawn: (i) for the identification of species, approaches are recommended that target mitochondrial cytochrome b sequences (RFLP, nested PCR or direct sequencing). However, they show limitations for the detection of hybrids (although natural hybrids are rare, the number of artificially produced hybrids in aquaculture is increasing) and for the differentiation of the following closely related species complexes: Acipenser gueldenstaedti,Acipenser baerii,Acipenser persicus,Acipenser naccarii; Acipenser medirostris,Acipenser mikadoi; and Scaphirhynchus albus,Scaphirhynchus plathorhynchus,Scaphirhynchus suttkusi; (ii) the identification of different populations of the same species is currently not feasible because genetic data are incomplete for most populations, and stocking and release programmes, which have become more and more common, often result in a mixture of phenotypes and genotypes, thereby impeding the creation and application of such a population identification system; (iii) source identification based on genetic approaches can be excluded at present because there are no genetic differences between wild and hatchery-raised fish. This is the result of the continuing restocking of natural populations with captive fish and vice versa. However, because rearing (i.e. environmental) conditions are different, methods focusing on differences in water quality or food seem to be more appropriate (for example differences in fatty acid composition). So far, very few studies have been conducted and therefore, source identification methods merit further exploration; and (iv) the age of a product in trade cannot be detected by DNA-based methods and protein profiling is undoubtedly impractical due to hard-to-perform, labour-and cost-intensive methods, which are highly susceptible to protein degradation. Arising from the limits discussed above, the next steps in the development of a uniform sturgeon identification system are proposed to be the following: (i) designation of qualified reference laboratories at national levels in (re-) exporting and importing countries. These should be approved through a standardized testing procedure, for instance a ring test on blind samples. Registered laboratories should be published and disseminated and their accreditations should be subject to certain guarantees regarding quality, economic independence and scientific rigour. Operational procedures have to be determined and standardized among reference laboratories; (ii) establishment of reference collections that are accessible to the reference laboratories containing DNA analyses results and information on the location and availability of tissue samples. This is highly recommended as an important step towards a population identification system and indispensable for a general species identification system; (iii) creation of a website access to the reference collections containing the reference database information about genetic samples, comparable to NCBI, which provides background data: sample location; population information; citation; available genetic data; location of archival storage; currently treated and distributed caviar and status of analysis. This website should also be a forum for the exchange of knowledge on and experiences with identification systems, species and population status information, relevant scientific research, etc.; and (iv) the outcome of the trade identification tests should be made available to the reference laboratories for future reference. The universal caviar labelling system could incorporate an indication of the verification of the consignment. In view of the lack of knowledge and the great need to develop a uniform identification system for Acipenseriformes with regard to the importance of the international caviar trade, further scientific guidance and appropriate research is strongly recommended. Progress should be assessed and exchanged on a regular basis. [source]


Ecological factors drive differentiation in wolves from British Columbia

JOURNAL OF BIOGEOGRAPHY, Issue 8 2009
Violeta Muñoz-Fuentes
Abstract Aim, Limited population structure is predicted for vagile, generalist species, such as the grey wolf (Canis lupus L.). Our aims were to study how genetic variability of grey wolves was distributed in an area comprising different habitats that lay within the potential dispersal range of an individual and to make inferences about the impact of ecology on population structure. Location, British Columbia, Canada , which is characterized by a continuum of biogeoclimatic zones across which grey wolves are distributed , and adjacent areas in both Canada and Alaska, United States. Methods, We obtained mitochondrial DNA control region sequences from grey wolves from across the province and integrated our genetic results with data on phenotype, behaviour and ecology (distance, habitat and prey composition). We also compared the genetic diversity and differentiation of British Columbia grey wolves with those of other North American wolf populations. Results, We found strong genetic differentiation between adjacent populations of grey wolves from coastal and inland British Columbia. We show that the most likely factor explaining this differentiation is habitat discontinuity between the coastal and interior regions of British Columbia, as opposed to geographic distance or physical barriers to dispersal. We hypothesize that dispersing grey wolves select habitats similar to the one in which they were reared, and that this differentiation is maintained largely through behavioural mechanisms. Main conclusions, The identification of strong genetic structure on a scale within the dispersing capabilities of an individual suggests that ecological factors are driving wolf differentiation in British Columbia. Coastal wolves are highly distinct and representative of a unique ecosystem, whereas inland British Columbia grey wolves are more similar to adjacent populations of wolves located in Alaska, Alberta and Northwest Territories. Given their unique ecological, morphological, behavioural and genetic characteristics, grey wolves of coastal British Columbia should be considered an Evolutionary Significant Unit (ESU) and, consequently, warrant special conservation status. If ecology can drive differentiation in a highly mobile generalist such as the grey wolf, ecology probably drives differentiation in many other species as well. [source]


Spatial analysis of taxonomic and genetic patterns and their potential for understanding evolutionary histories

JOURNAL OF BIOGEOGRAPHY, Issue 11 2004
Sophia A. Bickford
Abstract Aim, The aim of this research is to develop and investigate methods for the spatial analysis of diversity based on genetic and taxonomic units of difference. We use monophyletic groups of species to assess the potential for these diversity indices to elucidate the geographical components of macro-scaled evolutionary processes. Location, The range occupied by Pultenaea species in temperate and sub-tropical eastern Australia, extending from western South Australia (133° E,32° S) to Tasmania (146° E,43° S) to coastal central Queensland (148° E,20° S). Methods, We applied a series of both spatially explicit and spatially implicit analyses to explore the nature of diversity patterns in the genus Pultenaea, Fabaceae. We first analysed the eastern species as a whole and then the phylogenetic groups within them. We delineated patterns of endemism and biotic (taxon) regions that have been traditionally circumscribed in biogeographical studies of taxa. Centres of endemism were calculated using corrected weighted endemism at a range of spatial scales. Biotic regions were defined by comparing the similarity of species assemblages of grid cells using the Jaccard index and clustering similar cells using hierarchical clustering. On the basis that genetically coherent areas were likely to be more evolutionary informative than species patterns, genetic indices of similarity and difference were derived. A matrix of similarity distances between taxa was generated based on the number of shared informative characters of two sections of trnL-F and ndhF chloroplast nuclear regions. To identify genetically similar areas, we clustered cells using the mean genetic similarities of the species contained within each pair of cells. Measures of the mean genetic similarity of species in areas were delineated using a geographically local multi-scalar approach. Resultant patterns of genetic diversity are interpreted in relation to theories of the evolutionary relationships between species and species groups. Results, Centres of Pultenaea endemism were defined, those of clades 1 congruent with the spatially separated centres of clades 2 and 3. The taxonomic classification analysis defined cells with shared groups of species, which in some cases clustered when plotted in geographic space, defining biotic regions. In some instances the distribution of biotic regions was congruent with centres of endemism, however larger scale groupings were also apparent. In clade 1 one set of species was replaced by another along the extent of the range, with some connectivity between some geographically disjunct regions due to the presence of widespread species. In the combined analysis of clade 2 and 3 species the major biotic (taxonomic) groups with geographic coherence were defined by species in the respective clades, representing the geographic separation of these clades. However distinctive biotic regions within these main groupings of clades 2 and 3 were also apparent. Clustering cells using the mean genetic similarities of the species contained within each pair of cells indicated that some of the taxonomically defined biotic boundaries were the result of changes in composition of closely related species. This was most apparent in clades 1 and 2 where most cells were highly genetically similar. In clade 3 genetically distinct groups remained and were in part defined by sister taxa with disjunct distributions. Gradients in mean genetic similarity became more apparent from small to larger scales of analysis. At larger scales of analysis, regions of different levels of genetic diversity were delineated. Regions with highest diversity levels (lowest level of similarity) often represented regions where the ranges of phylogenetically distinctive species intergraded. Main conclusions, The combined analysis of diversity, phylogeny and geography has potential to reveal macro-scaled evolutionary patterns from which evolutionary processes may be inferred. The spatial genetic diversity indices developed in this study contribute new methods for identifying coherent evolutionary units in the landscape, which overcome some of the limitations of using taxonomic data, and from which the role of geography in evolutionary processes can be tested. We also conclude that a multiple-index approach to diversity pattern analysis is useful, especially where patterns may be the result of a long history of different environmental changes and related evolutionary events. The analysis contributes to the knowledge of large-scale diversity patterns of Pultenaea which has relevance for the assessment of the conservation status of the genus. [source]


Does designation of protected areas ensure conservation of tree diversity in the Sudanian dry forest of Burkina Faso?

AFRICAN JOURNAL OF ECOLOGY, Issue 2 2010
Souleymane Paré
Abstract The importance of conservation status of the forest (protected versus unprotected) at two sites with differing human population density (high versus low) on the tree diversity of a Sudanian dry forest in Burkina Faso was studied. All woody species were recorded in 127 circular plots (area = 456.16 m2), and density, dominance, frequency, importance value indices and a variety of diversity measures were calculated to assess the species composition, structure and heterogeneity. A total of 69 species, representing 26 families and 52 genera, were found. Combretaceae, Leguminosae subfamily Caesalpinioideae and Rubiaceae were the dominant families. Neither human pressure nor forest conservation status significantly influenced the tree species richness. Stem density and basal area were significantly higher at the site with high population density than otherwise. Fisher's diversity index revealed the unprotected forest at the site with low population density as the most diverse. We identified species with high conservation importance that should be enriched to maintain a viable population size. In conclusion, the current designation of protected areas seems inefficient at ensuring the conservation of tree diversity in the forest reserve. Thus, participatory conservation programme should be initiated. Résumé À deux endroits où la densité de population humaine est différente (forte versus faible), nous avons étudié l'importance du statut de conservation de la forêt (protégée ou non) pour la diversité d'une forêt soudanienne sèche du Burkina Faso. On a enregistré toutes les espèces ligneuses sur 127 parcelles circulaires (superficie = 456,16 m²), et on a calculé la densité, la dominance, les indices de valeurs d'importance value et une variété de mesures de diversité pour évaluer la composition, la structure et l'hétérogénéité des espèces. On a découvert un total de 69 espèces, représentant 26 familles et 52 genres. Les familles dominantes étaient Combretaceae, Leguminosae de la sous-famille Caesalpinioideae, et Rubiaceae. Ni la pression humaine, ni le statut de conservation des forêts n'influençaient significativement la richesse en espèces d'arbres. La densité des troncs et la surface terrière à la base étaient significativement plus élevées sur le site à forte densité de population. L'indice de diversité de Fisher a permis de révéler que la forêt non protégée du site à faible densité de population était la plus diversifiée. Nous avons identifié des espèces de haute valeur de conservation qui devraient être enrichies pour préserver une taille de population viable. En conclusion, la désignation actuelle d'aires protégées semble inefficace pour assurer la conservation de la diversité des arbres dans la réserve forestière. Donc, il faudrait initier un programme de conservation participative. [source]


A conservation assessment of the freshwater crabs of southern Africa (Brachyura: Potamonautidae)

AFRICAN JOURNAL OF ECOLOGY, Issue 1 2008
Neil Cumberlidge
Abstract Recent taxonomic revisions of the freshwater crabs of southern Africa (Angola, Botswana, Lesotho, Mozambique, Namibia, South Africa, Swaziland, Zambia and Zimbabwe) allow accurate depictions of their diversity, distribution patterns and conservation status. The southern African region is home to nineteen species of freshwater crabs all belonging to the genus Potamonautes (family Potamonautidae). These crabs show high levels of species endemism (84%) to the southern African region and to the country of South Africa (74%). The conservation status of each species is assessed using the IUCN (2003) Red List criteria, based on detailed compilations of the majority of known specimens. The results indicate that one species should be considered vulnerable, fifteen species least concern and three species data deficient. The results have been utilized by the IUCN for Red Lists, and may prove useful when developing a conservation strategy for southern Africa's endemic freshwater crab fauna. Résumé De récentes révisions de la taxonomie des crabes d'eau douce d'Afrique australe (Afrique du Sud, Angola, Botswana, Lesotho, Mozambique, Namibie, Swaziland, Zambie et Zimbabwe) permettent des descriptions précises de leur diversité, de leur schéma de distribution et de leur statut de conservation. L'Afrique australe accueille 19 espèces de crabes d'eau douce qui appartiennent toutes au genre Potamonautes (famille des Potamonautidae). Ces crabes présentent un degréélevé d'endémisme spécifique (84%) pour la région de l'Afrique australe et pour l'Afrique du Sud elle-même (74%). Le statut de conservation de chaque espèce est évalué selon les critères de la Liste rouge de l'UICN (2003), en se basant sur des compilations détaillées de la majorité des spécimens connus. Les résultats montrent qu'une des espèces devrait être considérée comme «vulnérable», 15 autres comme «préoccupation mineure» et trois n'ont que des «données insuffisantes». Les résultats ont été utilisés par l'UICN pour la Liste rouge et peuvent s'avérer utiles pour le développement d'une stratégie de conservation pour la faune des crabes d'eau douce endémiques d'Afrique australe. [source]