Conservation biologists have divided wildlife in two antagonist categories—native and introduced populations—because they defend the hypothesis that the latter acquires or expresses harmful qualities ...that a population that remains in its original environment does not possess. Invasion biology has emerged as a branch of conservation biology dedicated exclusively to conflicts between introduced wildlife and human interest, including the protection of biodiversity. For invasion biology, the damage caused by native species is different and must be managed differently. However, the consensus around this native–introduced dichotomy is not universal, and a debate has intensified in recent years. The objective of this work was to compare the impacts of native and introduced species of terrestrial vertebrates of the United States using the dataset provided by Wildlife Services (WS), which depend upon the Animal and Plant Health Inspection Service of the Department of Agriculture. Annually, they receive thousands of reports and complaints of human–wildlife conflicts. I analyzed the WS databases and found, against expectations, that native species produce significantly more damage than nonnative ones, especially regarding damage to agriculture, property and health and safety. In the category of impacts on biodiversity and natural ecosystems, the differences were minor. I discuss several potential explanations of these patterns in the results. I also discuss the ecological foundations of the native–introduced dichotomy hypothesis.
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Class 1 integrons are one of the most successful elements in the acquisition, expression and spread of antimicrobial resistance genes (ARG) among clinical isolates. Little is known about the gene ...flow of the components of the genetic platforms of class 1 integrons within and between bacterial communities. Thus it is important to better understand the interactions among "environmental" intI1, its genetic platforms and its distribution with human activities.
An evaluation of two types of genetic determinants, ARG (sul1 and qacE1/qacEΔ1 genes) and lateral genetic elements (LGE) (intI1, ISCR1 and tniC genes) in a model of a culture-based method without antibiotic selection was conducted in a gradient of anthropogenic disturbances in a Patagonian island recognized as being one of the last regions containing wild areas. The intI1, ISCR1 genes and intI1 pseudogenes that were found widespread throughout natural communities were not associated with urbanization (p>0.05). Each ARG that is embedded in the most common genetic platform of clinical class 1 integrons, showed different ecological and molecular behaviours in environmental samples. While the sul1 gene frequency was associated with urbanization, the qacE1/qacEΔ1 gene showed an adaptive role to several habitats.
The high frequency of intI1 pseudogenes suggests that, although intI1 has a deleterious impact within several genomes, it can easily be disseminated among natural bacterial communities. The widespread occurrence of ISCR1 and intI1 throughout Patagonian sites with different degree of urbanization, and within different taxa, could be one of the causes of the increasing frequency of multidrug-resistant isolates that have characterized Argentina for decades. The flow of ARG and LGE between natural and clinical communities cannot be explained with a single general process but is a direct consequence of the interaction of multiple factors operating at molecular, ecological, phylogenetic and historical levels.
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Abstract Assessing the genetic diversity and gene flow among populations in combination with ecological data provides valuable insight into the spatial use and genetic structure of wildlife. ...Anthropic impact generates landscape changes that threaten species by favouring their isolation in small patches and limiting their connectivity. However, in some cases, it can increase genetic exchange among wild populations. Here, we used a set of 16 microsatellites to study the genetic diversity, population genetic structure, and historical and current gene flow of coypu (Myocastor coypus) populations, a semi-aquatic rodent that inhabits watercourses of the highly anthropized agroecosystems of the Pampas region. Our results showed moderate to high levels of genetic diversity and revealed the existence of genetic structure among populations. Bayesian analysis showed different patterns of genetic structure among and within sampling sites. Also, the patterns of historical gene flow differed from that seen today. These results, together with previous studies, suggest that anthropic pressure, habitat fragmentation and ephemeral landscapes in a highly modified ecosystem could alter the dispersal patterns of coypus in their native range, which would otherwise be different in an environment with low anthropic impact. The results provide new information that could be used in effective conservation programmes.
People’s attitudes to animals are becoming increasingly important for the success of invasive species management. We asked college students from Argentina to fill a questionnaire that included a ...question about their favorite free-living animal. A total of 159 responses were obtained. Native species were significantly less preferred than non-native species. We tested if these preferences were associated with animal stereotypes. The stereotype hypothesis predicts that animals from the contemptible stereotype (invertebrate, rodents, and reptiles) should be the least preferred taxa, and animals from the protective stereotype (pets, horses, and primates) should be the most preferred taxa; animals from the subordination (lagomorphs and birds) and threatening–awe stereotype (large carnivores) should show intermediate preferences. The first prediction was supported. However, students showed significant preference for non-native taxa included in the threatening–awe stereotype. We proposed that people prefer large carnivores (stereotypically strong, intelligent, and beautiful animals) when they are exotic, because they did not represent a risk.
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The screaming hairy armadillo (
Chaetophractus vellerosus
) is a mammal species containing disjunct and isolated populations. In order to assess the effect of habitat fragmentation and geographic ...isolation, we developed seven new microsatellite loci isolated from low-coverage genome shotgun sequencing data for this species. Among these loci, six microsatellites were found to be polymorphic with 8–26 alleles per locus detected across 69 samples analyzed from a relictual population of the species located in the northeast of the Buenos Aires Province (Argentina). Mean allelic richness and polymorphic information content were 15 and 0.75, with observed and expected heterozygosities ranging from 0.40 to 0.67 and 0.58 to 0.90, respectively. All loci showed departures from Hardy–Weinberg equilibrium. The analysis of population structure in this relictual population revealed three groups of individuals that are genetically differentiated. These newly developed microsatellites will constitute a very useful tool for the estimation of genetic diversity and structure, population dynamics, social structure, parentage and mating system in this little-studied armadillo species. Such genetic data will be particularly helpful for the development of conservation strategies for this isolated population and also for the endangered Bolivian populations previously recognized as a distinct species (
Chaetophractus nationi
).
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The coypu, or nutria (Myocastor coypus), is a semiaquatic rodent intensively harvested for fur and damage control. We conducted a survey along the Luján River in Argentina to determine environmental ...factors affecting the distribution of coypu in its natural range. In each of 82 600-m transects randomly assigned along the river, we recorded the presence of coypu and habitat characteristics related to attributes of the river, nearby vegetation, and human activity. Coypu distribution was positively related to availability of grasslands used for extensive livestock production and negatively related to local human perturbations. Lowland prairies would provide an abundant and stable source of food to coypu, which could be used as a profitable natural resource in low productive areas of the Pampas region.
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We used microhistological analysis of feces to study diet composition and food selection of coypu (Myocastor coypus) in 3 riparian habitats of the Pampas region of Argentina. The main food types were ...monocots associated with water (40-60% of diet), which were consumed significantly more than in proportion to availability. Terrestrial monocots, represented 30-35% of the diet and were consumed in proportion to availability. Coypu ate dicots (0-15%) significantly less than the proportion available. The most preferred plant species in the diet were Eleocharis bonariensis in winter and spring (15-37%), and Lemna sp. in summer and autumn (20-30% of diet). Coypu consumed <2% of each of the 6 crops available, regardless of the phenological condition of the crops. In a field experiment, we equalized availability of a terrestrial species (Lolium multiflorum) and a hygrophylic species (E. bonariensis) at 2 distances from water, and the results suggested that dietary selection was dependent on the distribution of food sources in relation to distance to shelter. We concluded than coypu did not behave as a pest of agrosystems, provided that the riparian habitat included at least a narrow fringe of natural vegetation, as occurs in most of the Pampas Plain.
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