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Anthropogenic Factors (anthropogenic + factor)
Selected AbstractsThe Bushmeat Trade: Increased Opportunities for Transmission of Zoonotic DiseaseMOUNT SINAI JOURNAL OF MEDICINE: A JOURNAL OF PERSONALIZED AND TRANSLATIONAL MEDICINE, Issue 5 2009William B. Karesh DVM Abstract Bushmeat is a term that refers to the use of wild animals, ranging from cane rats to gorillas, for food. The term typically refers to the practice in forests of Africa. The bushmeat trade is an example of an anthropogenic factor that provides opportunities for the transmission of diseases from wildlife to humans. The expansion of the bushmeat trade over the past 2 decades has provided a venue for the emergence of zoonotic diseases by providing an increased opportunity for the transmission of organisms known to cause disease and organisms with an unknown impact on humans. Because the bushmeat trade is embedded in a complex cultural, political, and economic context, efforts to prevent the emergence of zoonoses require a multidisciplinary approach. Mt Sinai J Med 76:429,434, 2009. © 2009 Mount Sinai School of Medicine [source] Residence time and potential range: crucial considerations in modelling plant invasionsDIVERSITY AND DISTRIBUTIONS, Issue 1 2007John R. U. Wilson ABSTRACT A prime aim of invasion biology is to predict which species will become invasive, but retrospective analyses have so far failed to develop robust generalizations. This is because many biological, environmental, and anthropogenic factors interact to determine the distribution of invasive species. However, in this paper we also argue that many analyses of invasiveness have been flawed by not considering several fundamental issues: (1) the range size of an invasive species depends on how much time it has had to spread (its residence time); (2) the range size and spread rate are mediated by the total extent of suitable (i.e. potentially invasible) habitat; and (3) the range size and spread rate depend on the frequency and intensity of introductions (propagule pressure), the position of founder populations in relation to the potential range, and the spatial distribution of the potential range. We explored these considerations using a large set of invasive alien plant species in South Africa for which accurate distribution data and other relevant information were available. Species introduced earlier and those with larger potential ranges had larger current range sizes, but we found no significant effect of the spatial distribution of potential ranges on current range sizes, and data on propagule pressure were largely unavailable. However, crucially, we showed that: (1) including residence time and potential range always significantly increases the explanatory power of the models; and (2) residence time and potential range can affect which factors emerge as significant determinants of invasiveness. Therefore, analyses not including potential range and residence time can come to misleading conclusions. When these factors were taken into account, we found that nitrogen-fixing plants and plants invading arid regions have spread faster than other species, but these results were phylogenetically constrained. We also show that, when analysed in the context of residence time and potential range, variation in range size among invasive species is implicitly due to variation in spread rates, and, that by explicitly assuming a particular model of spread, it is possible to estimate changes in the rates of plant invasions through time. We believe that invasion biology can develop generalizations that are useful for management, but only in the context of a suitable null model. [source] Whole effluent toxicity testing,usefulness, level of protection, and risk assessmentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2000Peter M. Chapman Abstract The general status of whole effluent toxicity (WET) tests is assessed relative to their generally accepted purpose of identifying, characterizing, and eliminating toxic effects of effluents on aquatic resources. Although WET tests are useful, they are not perfect tools (no perfect tools exist). Imperfections include the innate variability of these tests, due both to biotic and anthropogenic factors; the reality of species differences both between the laboratory and the field and within the field; and differences between the laboratory and the receiving environment. Whole effluent toxicity tests may be overprotective (because of their conservative nature, the absence of environmental and ecological processes that could ameliorate exposure, and sensitivity to noncontaminant effects), underprotective (because the most sensitive species cannot be tested, multiple stresses tend to be present in the receiving environment, and failure to account for food chain effects or all possible endpoints), or offer an uncertain level of protection (intermittent doses and mixtures in the environment, adaptations, and hormesis). The implication of hormesis and inverted U-shaped dose responses for WET testing are reviewed in particular detail. Comparisons to field conditions indicate that WET tests are not reliable predictors of effects or lack of effects in the receiving environment. Whole effluent toxicity tests are only the first stage in a risk assessment and as such identify hazard, not risk. Identification of risk requires discarding the concept of independent applicability. The appropriate use of WET tests is identified in the context of their advantages and disadvantages. [source] Distribution of benthic diatoms in U.S. rivers in relation to conductivity and ionic compositionFRESHWATER BIOLOGY, Issue 8 2003Marina Potapova Summary 1We quantified the relationships between diatom relative abundance and water conductivity and ionic composition, using a dataset of 3239 benthic diatom samples collected from 1109 river sites throughout the U.S.A. [U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program dataset]. This dataset provided a unique opportunity to explore the autecology of freshwater diatoms over a broad range of environmental conditions. 2Conductivity ranged from 10 to 14 500 ,S cm,1, but most of the rivers had moderate conductivity (interquartile range 180,618 ,S cm,1). Calcium and bicarbonate were the dominant ions. Ionic composition, however, varied greatly because of the influence of natural and anthropogenic factors. 3Canonical correspondence analysis (CCA) and Monte Carlo permutation tests showed that conductivity and abundances of major ions (HCO + CO, Cl,, SO, Ca2+, Mg2+, Na+, K+) all explained a statistically significant amount of the variation in assemblage composition of benthic diatoms. Concentrations of HCO + CO and Ca2+ were the most significant sources of environmental variance. 4The CCA showed that the gradient of ionic composition explaining most variation in diatom assemblage structure ranged from waters dominated by Ca2+ and HCO + CO to waters with higher proportions of Na+, K+, and Cl,. The CCA also revealed that the distributions of some diatoms correlated strongly with proportions of individual cations and anions, and with the ratio of monovalent to divalent cations. 5We present species indicator values (optima) for conductivity, major ions and proportions of those ions. We also identify diatom taxa characteristic of specific major-ion chemistries. These species optima may be useful in future interpretations of diatom ecology and as indicator values in water-quality assessment. [source] The Deciduous Forest , Boreal Forest EcotoneGEOGRAPHY COMPASS (ELECTRONIC), Issue 7 2010David Goldblum Ecotones have been subject to significant attention over the past 25 years as a consensus emerged that they might be uniquely sensitive to the effects of climate change. Most ecotone field studies and modeling efforts have focused on transitions between forest and non-forest biomes (e.g. boreal forest to Arctic tundra, forest to prairie, subalpine forests to alpine tundra) while little effort has been made to evaluate or simply understand forest,forest ecotones, specifically the deciduous forest , boreal forest ecotone. Geographical shifts and changes at this ecotone because of anthropogenic factors are tied to the broader survival of both the boreal and deciduous forest communities as well as global factors such as biodiversity loss and dynamics of the carbon cycle. This review summarizes what is known about the location, controlling mechanisms, disturbance regimes, anthropogenic impacts, and sensitivity to climate change of the deciduous forest , boreal forest ecotone. [source] A comparison of sex ratio, birth periods and calf survival among Serengeti wildebeest sub-populations, TanzaniaAFRICAN JOURNAL OF ECOLOGY, Issue 4 2009Vedasto G. NdibalemaArticle first published online: 31 AUG 200 Abstract Although adaptation and environmental conditions can easily predict demographic variation in most savannah ungulates, no study on demographic consequences arising from natural and anthropogenic factors among Serengeti wildebeest (Connochaetes taurinus) sub-populations in Tanzania has been carried out. Here, I report estimates of annual sex ratio, calf and yearling survival rate and birth seasonality between resident and migratory sub-populations to explore demographic patterns arising from the different age and sex structure. The results indicate significantly higher female-biased sex ratios in the resident and almost even sex ratios among individual migrants. The calf recruitment estimated as mother: offspring ratios indicate a more synchronous birth in the migrant than the resident sub-population. Also, birth seasonality in the migratory sub-population coincided with seasonal variability of rainfall and the timing of the birth peak was more variable in the migrants than the resident sub-population. The migratory sub-population had a higher annual proportional mean calf survival estimate (0.84) than that of the residents (0.44) probably due to higher mortality resulting from predation in the western corridor. However, the proportion of yearling survival estimates was much lower (0.31) in the migrants and relatively higher (0.39) in the residents. Different demographic outcomes resulting from environment, predation, movements and ecological factors including resource competition have conservation implications for the two sub-populations. Résumé Bien que l'adaptation et les conditions environnementales puissent facilement aider à prédire la variation démographique de la plupart des ongulés de savane, aucune étude n'a encore été réalisée sur les conséquences démographiques de facteurs naturels et anthropiques chez les sous-populations de gnous (Connochaetes taurinus) du Serengeti, en Tanzanie. Ici, je rapporte des estimations du sex-ratio annuel, du taux de survie des veaux et des jeunes d'un an et le caractère saisonnier des naissances entre des sous-populations résidentes et migratrices, pour explorer les schémas démographiques qui se dessinent à partir des différentes structures d'âge et de sexe. Les résultats indiquent un sex-ratio significativement biaisé en faveur des femelles chez les animaux résidents et un sex-ratio presque équilibré chez les individus migrateurs. Le recrutement des veaux estimé selon le rapport mère/progéniture indique des naissances plus synchrones chez la sous-population migratrice que chez la résidente. La saisonnalité des naissances chez la sous-population migratrice coïncidait avec la variabilité saisonnière des chutes de pluies, et le timing du pic des naissances était plus variable chez la sous-population migratrice que chez la résidente. La sous-population migratrice avait une espérance de vie annuelle proportionnelle des veaux plus élevée (0,84) que la résidente (0,44), probablement en raison de la plus forte mortalité causée par des prédateurs dans le corridor occidental. Cependant, les estimations de la proportion de jeunes d'un an survivants étaient beaucoup plus basses (0,31) chez les migrateurs et relativement plus hautes (0,39) chez les résidents. Les résultats démographiques différents des facteurs environnementaux, de la prédation, des déplacements et des facteurs écologiques, y compris la compétition pour les ressources, ont des implications pour la conservation des deux sous-populations. [source] New evidence for the occurrence of Eurasian lynx (Lynx lynx) in medieval Britain,JOURNAL OF QUATERNARY SCIENCE, Issue 1 2006David A. Hetherington Abstract The presence of Eurasian lynx as a former native species in Britain during the Holocene is known from bones recovered from several sites. AMS radiocarbon dating of lynx bone recovered from two sites in the Craven area of northern England gave 1842,±,35 14C,yr,BP and 1550,±,24 14C,yr,BP, together representing the youngest dates for lynx from England, and in the case of the latter, the youngest for Britain as a whole. These dates support the view that the game animal whose occurrence in the nearby Lake District is described in the early 7th century Cumbric text Pais Dinogad, and whose translation to date has been problematic, is a lynx. The occurrence of lynx in early medieval Britain shows that earlier periods of climate change, previously blamed for the species' extinction in Britain, were not responsible. Instead, anthropogenic factors such as severe deforestation, declining deer populations, and persecution, are likely to have caused the extirpation of lynx in Britain. Consequently, the lynx qualifies as a candidate for reintroduction. Large-scale reafforestation, the growth of deer populations, and more positive attitudes towards carnivores in modern society, could permit the restoration of lynx to Britain, particularly in Scotland. Copyright © 2005 John Wiley & Sons, Ltd. [source] Genetic variability and differentiation in red deer (Cervus elaphus) from Scotland and EnglandJOURNAL OF ZOOLOGY, Issue 3 2006S. S. Hmwe Abstract Samples from 69 British red deer Cervus elaphus scoticus from seven populations in Scotland and England were analysed with respect to variability within and differentiation among stocks using 11 polymorphic microsatellite loci and 439 bp of the mitochondrial control region. The results clearly showed the effects of anthropogenic factors on British red deer. On the whole, variability values were within the species' reported range. The island population of Islay, Scotland, however, while showing average microsatellite variability, exhibited no mitochondrial variation at all. One microsatellite locus was monomorphic in three Scottish populations (Islay, Dunachton and Achnacarry). Overall and pairwise FST values indicate considerable differentiation among the populations studied, but Dunachton and Achnacarry, two adjacent populations free from recorded introductions, showed only a little differentiation and were paired in trees based on genetic distances. In terms of variability, no statistically significant differences were observed between island and mainland populations and the overall test of isolation by distance was negative. Possible reasons for the genetic patterns observed, such as differences in human impact on the populations, are discussed. [source] Comparative assessment of the water balance and hydrology of selected Ethiopian and Kenyan Rift LakesLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 3 2008Tenalem Ayenew Abstract The study area is part of the East African Rift system, characterized by a cluster of lakes occupying an extremely faulted rift floor with geothermal manifestations. Some of the lakes illustrated contrasting water levels and size evolution over the last few decennia, believed to have been caused by various natural and anthropogenic factors. The relative importance of these factors, however, is unknown. This study attempts to present the hydrology of the lakes in a broader context, by giving more emphasis to lake water level fluctuations and to the water balance. These factors have far-reaching implications in regard to future management of the lake basin water. It also provides information on the relation of the groundwater with the lakes, and with the local and regional groundwater flow system from the adjacent highlands to the floor of the Rift. The methods utilized in this study include conventional hydrogeological field surveys, and hydrometeorological and data analyses, coupled with digital image processing and spatial analysis under a Geographic Information System environment. Ancillary supporting information has been obtained from environmental isotopes and hydrochemical data. The study results indicate the terminal Ethiopian lakes changed in size and water level significantly over the last half century. In contrast, the Kenyan lakes only exhibited slight changes. The lakes in both countries exhibit a striking similarity in their subsurface hydraulic connection, and are strongly governed by complex rift geological structures. Groundwater plays a vital role in the water balance of the study lakes. The study results indicate that future sustainable use of the study lakes demands that serious attention be given to the role of the groundwater component of the lake water balances. [source] Metals in the sediments of the Huron-Erie Corridor in North America: Factors regulating metal distribution and mobilizationLAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 4 2007Ewa Szalinska Abstract Sediment samples from the Huron-Erie Corridor (Great Lakes, North America) were collected to quantify the relative importance of natural and anthropogenic sources of contamination, and to study the spatial metal distribution patterns of metals as a function of the characteristics of the Corridor sediments. A stratified random sampling design was used to measure the spatial patterns of metal inputs, settling and sorting along the length of the Corridor. Factors regulating metal mobilization were assessed by determining metal affinities with the total organic fraction (TOM), the mineral fraction (represented as Al), and the granulometric characteristic (represented as <0.063 mm fraction). The study revealed that anthropogenic factors primarily regulated metal distributions and mobilization throughout the Huron-Erie Corridor. In the St. Clair and Detroit Rivers, the spatial pattern of metal distributions strongly reflected local industrial sources. In the Walpole Delta and Lake St. Clair, however, inorganic (clays) and organic (TOM) particles dominated the contaminant distribution. Sediment contamination issues throughout the Huron-Erie Corridor were dominated by mercury, released from sources along the St. Clair and Detroit Rivers. The mean enrichment factor EFAl for mercury in these sediments has reached 68.3. Other metal pollutants were confined to the sediments in the lower depositional reach of the Corridor. [source] Mapping sensitivity to land degradation in Extremadura.LAND DEGRADATION AND DEVELOPMENT, Issue 2 2009SW Spain Abstract An assessment of sensitivity to land degradation has been carried out in the Extremadura region, SW Spain, by means of a modelling approach developed by the European Commission funded MEDALUS project (Mediterranean Desertification and Land Use) which identifies such areas on the basis of an index (Environmentally Sensitive Area index, ESA index) that incorporates data on environmental quality (climate, vegetation, soil) as well as anthropogenic factors (management). Two maps of environmental sensitivity (ES) to degradation with different legend resolution (four and eight classes of sensitivity) have been made and tested by comparing classes of the legends with an extensive number (2690) of true field data gathered from plots distributed all over the study region. Independent variables of validation consisted of nine degradation-related types of data and the method tested the performance of the whole model and the statistical separability among classes of sensitivity, as well as the capability of the variables in delimiting the classes. Results showed a good performance of the whole model to both, the map of four and eighth classes of sensitivity. Separation among classes of sensitivity showed a slightly different behaviour of both maps, identifying transitional classes in the map of eight classes where classification could be improved in terms of the ranges of ESA index values assigned to the different classes. Copyright © 2008 John Wiley & Sons, Ltd. [source] An improved method for determination of Holocene coastline changes around two ancient settlements in southern Anatolia: a geoarchaeological approach to historical land degradation studiesLAND DEGRADATION AND DEVELOPMENT, Issue 4 2003Y. Bal Abstract Two well-known ancient sites in southern Anatolia were selected to investigate and quantify the impact of historical land degradation on the Mediterranean coast of Turkey. These sites are the Luwian settlements of Kelenderis (modern Ayd,nc,k) and nearby Nagidos (Bozyaz,), both in Mersin Province and both occupied since around 4000,BP. Changes in local climatic conditions over this period have produced variations in the rates of fluvial transport of sediment/soil from the hinterland into the relevant deltaic regions, thus influencing rates of coastal progradation and aggradation. In addition, both eustatic and neotectonic movements have contributed to deltaic subsidence and/or hinterland uplift, with consequential impact on coastal evolution (positive or negative). The novel geoarchaeological methodology adopted in this study involves the creation of a graphical archive from detailed and standardised measurements taken from rectified mono- and stereoscopic aerial photographs. These archival data were then integrated with data from several types of historical map and field measurements in order to develop a geographical information system (GIS) database that could be interrogated, enabling graphical models of past coastal change to be constructed and calculations then made of the coastal configurations at successive historical periods. These calculations reveal that over the past 6000 years there has been only limited erosion/degradation in the karstic hinterland supplying the sediment to these two study sites (contrary to some previous statements concerning the high degradation risk of Mediterranean karst terrains). Furthermore, rates of progradation in each delta appear to have become diminished or even reversed in the past several decades as a result of both natural and anthropogenic factors. The precise contribution of neotectonic movements in this seismically active zone remains unquantified and is a topic requiring further interdisciplinary study. Copyright © 2003 John Wiley & Sons, Ltd. [source] Farmland degradation in the mountains of Nepal: a study of watersheds ,with' and ,without' external interventionLAND DEGRADATION AND DEVELOPMENT, Issue 6 2002G. B. Thapa Abstract Amidst growing concerns about farmlands conservation, this paper examines the status of farmlands in two mountain watersheds ,with' and ,without' external intervention, located in the western hills of Nepal. Information was obtained from a household survey and group discussions conducted during April to September 1999. The severity of soil erosion from farmers' perspectives, density of landslides, soil nutrient balance and change in crop yield have been adopted as indicators of the status of the land. Results of the analysis indicate that land resources in both watersheds are undergoing degradation, though the causes and extent of degradation vary from one type of land to another. Upland crop terraces, locally called bari, are undergoing degradation most seriously under the combined influence of severe soil erosion, landslide and the depletion of soil nutrients. In particular, soil erosion has severely affected nearly half of the upland crop terraces in both watersheds due to a number of natural and anthropogenic factors ranging from weak geological structure to arable agriculture. Landslide and nutrient depletion have affected all types of farmlands except homesteads in both watersheds. Overall, the extent and intensity of land degradation is relatively high in the non-project area, as farmers were not provided with necessary technical and financial support. A broad strategy has been outlined for effective conservation of farmlands. Copyright © 2002 John Wiley & Sons, Ltd. [source] Modeling the effects of El Niño, density-dependence, and disturbance on harbor seal (Phoca vitulina) counts in Drakes Estero, California: 1997,2007MARINE MAMMAL SCIENCE, Issue 1 2009Benjamin H. Becker Abstract Harbor seal (Phoca vitulina) haul-out site use may be affected by natural or anthropogenic factors. Here, we use an 11-yr (1997,2007) study of a seal colony located near a mariculture operation in Drakes Estero, California, to test for natural (El Niño-Southern Oscillation (ENSO), density-dependence, long-term trends) and anthropogenic (disturbance or displacement related to oyster production activities) factors that may influence the use of haul-out subsites. Annual mariculture related seal disturbance rates increased significantly with increases in oyster harvest (rs= 0.55). Using generalized linear models (GLMs) ranked by best fit and Akaike's Information Criteria, ENSO and oyster production (as a proxy for disturbance/displacement) best explained the patterns of seal use at all three subsites near the mariculture operations, with effects being stronger at the two subsites closest to operations. Conversely, density-dependence and linear trend effects poorly explained the counts at these subsites. We conclude that a combination of ENSO and mariculture activities best explain the patterns of seal haul-out use during the breeding/pupping season at the seal haul-out sites closest to oyster activities. [source] Genetic variation within and among fragmented populations of lesser prairie-chickens (Tympanuchus pallidicinctus)MOLECULAR ECOLOGY, Issue 3 2003Ronald A. Van Den Bussche Abstract As a result of recurrent droughts and anthropogenic factors, the range of the lesser prairie-chicken (Tympanuchus pallidicinctus) has contracted by 92% and the population has been reduced by approximately 97% in the past century, resulting in the smallest population size and most restricted geographical distribution of any North American grouse. We examined genetic variation through DNA sequence analysis of 478 base pairs of the mitochondrial genome and by assaying allelic variation at five microsatellite loci from lesser prairie-chickens collected on 20 leks in western Oklahoma and east-central New Mexico. Traditional population genetic analyses indicate that lesser prairie-chickens maintain high levels of genetic variation at both nuclear and mitochondrial loci. Although some genetic structuring among lesser prairie-chicken leks was detected within Oklahoma and New Mexico for both nuclear and mitochondrial loci, high levels of differentiation were detected between Oklahoma and New Mexico populations. Nested-clade analysis of mitochondrial haplotypes revealed that both historic and contemporary processes have influenced patterns of haplotype distributions and that historic processes have most likely led to the level of differentiation found between the Oklahoma and New Mexico populations. [source] Development and characterization of novel microsatellite markers from the olive ridley sea turtle (Lepidochelys olivacea)MOLECULAR ECOLOGY RESOURCES, Issue 1 2004Ramesh K. Aggarwal Abstract Olive ridley turtles, although widely distributed globally and in Indian coastal waters, have undergone declines in recent years due to anthropogenic factors, particularly fishery-related mortality. Assessment of genetic variability in existing populations is critical to the development of effective conservation strategies. Here we describe the development of six highly polymorphic microsatellite loci from a simple sequence repeat-enriched genomic DNA library of olive ridley turtle. Characterization of five of these loci using 83 individual olive ridley turtles revealed eight to 24 alleles per locus, high observed and expected heterozygosity values and broad cross-species amplifications. The sixth microsatellite was found to be monomorphic in the olive ridley samples but was polymorphic in two related marine turtle species. These microsatellites thus provide efficient genetic markers to understand the population structure, phylogeography and species relationships of olive ridley and other marine turtle species. [source] The impact of fallback foods on wild ring-tailed lemur biology: A comparison of intact and anthropogenically disturbed habitatsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Michelle L. Sauther Abstract Fallback foods are often viewed as central in shaping primate morphology, and influencing adaptive shifts in hominin and other primate evolution. Here we argue that fruit of the tamarind tree (Tamarindus indica) qualifies as a fallback food of ring-tailed lemurs (Lemur catta) at the Beza Mahafaly Special Reserve (BMSR), Madagascar. Contrary to predictions that fallback foods may select for dental and masticatory morphologies adapted to processing these foods, consumption of tamarind fruit by these lemurs leaves a distinct pattern of dental pathology among ring-tailed lemurs at BMSR. Specifically, the physical and mechanical properties of tamarind fruit likely result in a high frequency of severe tooth wear, and subsequent antemortem tooth loss, in this lemur population. This pattern of dental pathology is amplified among lemurs living in disturbed areas at Beza Mahafaly, resulting from a disproportionate emphasis on challenging tamarind fruit, due to few other fruits being available. This is in part caused by a reduction in ground cover and other plants due to livestock grazing. As such, tamarind trees remain one of the few food resources in many areas. Dental pathologies are also associated with the use of a nonendemic leaf resource Argemone mexicana, an important food during the latter part of the dry season when overall food availability is reduced. Such dental pathologies at Beza Mahafaly, resulting from the use or overemphasis of fallback foods for which they are not biologically adapted, indicate that anthropogenic factors must be considered when examining fallback foods. Am J Phys Anthropol 140:671,686, 2009. © 2009 Wiley-Liss, Inc. [source] Assessment of organochlorine pesticides and metals in ring-tailed lemurs (Lemur catta) at Beza Mahafaly Special Reserve, MadagascarAMERICAN JOURNAL OF PRIMATOLOGY, Issue 12 2009Thomas R. Rainwater Abstract Like most of Madagascar's endemic primates, ring-tailed lemurs (Lemur catta) face a number of threats to their survival. Although habitat loss is of greatest concern, other anthropogenic factors including environmental contamination may also affect lemur health and survival. In this study, we examined ring-tailed lemurs from the Beza Mahafaly Special Reserve (BMSR), southern Madagascar for exposure to organochlorine (OC) pesticides and metals and examined differences in contaminant concentrations between sexes and among age groups, troops, and habitats. A total of 14 pesticides and 13 metals was detected in lemur blood (24 individuals) and hair (65 individuals) samples, respectively. p,p,-DDT, heptachlor, aldrin, heptachlor epoxide, endrin aldehyde, and endrin were among the most prevalent pesticides detected. Surprisingly, the persistent metabolite of p,p,-DDT, p,p,-DDE, was not detected. The most commonly detected metals were aluminum, zinc, boron, phosphorus, silicon, and copper, whereas metals considered more hazardous to wildlife (e.g. arsenic, cadmium, lead, selenium, vanadium) were not found above detection limits. Overall, concentrations of OC pesticides and metals were low and similar to those considered to be background concentrations in other studies examining the ecotoxicology of wild mammals. Few inter-sex, -age, -troop, and -habitat differences in contaminant concentrations were observed, suggesting a uniform distribution of contaminants within the reserve. Several statistically significant relationships between lemur body size and contaminant concentrations were observed, but owing to the lack of supportive data regarding contaminant exposure in wild primates, the biological significance of these findings remains uncertain. Results of this study document exposure of ring-tailed lemurs at BMSR to multiple OC pesticides and metals and provide essential baseline data for future health and toxicological evaluations of lemurs and other wild primates, especially those in regions with expanding agricultural and mining operations. Am. J. Primatol. 71:998,1010, 2009. © 2009 Wiley-Liss, Inc. [source] Ecological effects of major injuries in diamondback terrapins: implications for conservation and managementAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 4 2009K. K. Cecala Abstract 1.Many turtle species frequently suffer major injuries due to attempted predation or anthropogenic factors. Diamondback terrapins (Malaclemys terrapin) are one species known to be affected by anthropogenic activity, but little is known about the causes of injuries. In declining diamondback terrapin populations, learning more about causes and results of injuries can be helpful in developing sound management plans. 2.Patterns of limb loss and major shell injuries were examined in a population of terrapins studied for 24 years at Kiawah Island, South Carolina to infer the causes and effects of injuries and possible predators on terrapins. 3.The rate of shell injuries increased temporally, possibly as a result of increased watercraft activity. Because no differences in rates of limb loss were found between males and females, limb loss probably results from aquatic encounters (i.e. limb loss does not appear to be the result of terrestrial predation during nesting). Furthermore, males experienced reduced body condition when injured, and terrapins with a major injury had lower survivorship than uninjured terrapins. 4.Therefore, in addition to reducing sources of mortality and protecting nesting habitat, measures to protect terrapins from watercraft activity may increase the survivorship of adult terrapins. Copyright © 2008 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||