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8,987 result(s) for "biological inventories"
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Gastrointestinal helminths of opossums (Mammalia: Didelphidae) from Bolivia
A total of 32 taxa of helminths were recovered from 52 individuals corresponding to 17 species of didelphiomorph marsupials collected across Bolivia. From these, 20 taxa are registered for the first time in this landlocked South American country, including the cestode Mathevotaenia bivittata, and the nematodes Moennigia sp., Travassostrongylus callis, Viannaia didelphis, V. hamata, V. metachirops, V. minispicula, V. philanderi, V. simplicispicula, V. skrjabini, V. viannai, Cruzia tentaculata, Monodelphoxyuris dollmeiri, Neohilgertia venusti, Pterygodermatites elegans, Pterygodermatites jeagerskioldi, Spirura guianensis, Gongylonemoides marsupialis, Turgida turgida and Trichuris reesali. We report for the first time parasites for Marmosops bishopi, Monodelphis emiliae, Monodeplhis glirina, Monodelphis sanctarosae, Monodelphis peruviana and Thylamys sponsorius and document 38 new records of parasites infecting marsupials. Twenty-six taxa of helminths infect 2 or more species of didelphiomorph marsupials, with the exception of Travassostrongylus callis, Viannaia didelphis, V. hamata, V. minispicula and V. hamate, which infected individuals of a single species.
Global patterns of specialization and coexistence in bird assemblages
Aim: Increased specialization has been hypothesized to facilitate local coexistence and thus high species richness, but empirical evaluations of the richnessspecialization relationships have been relatively scant. Here, we provide a first assessment of this relationship for terrestrial bird assemblages at global extent and from fine to coarse grains. Location: World-wide. Methods: We use two indices of specialization that describe species-level resource use: diet and habitat specialization. The relationship between richness and mean assemblage-level specialization was independently assessed at realm, biome-realm, 12,100 km 2 equal-area grid cells and fine-grained scales. To identify assemblages that are diverse relative to environmental conditions we: (1) applied quantile regressions, (2) statistically accounted for other environmental variables which may constrain richness, and (3) parsed the data according to the residuals of a model relating species richness to the environmental variables. Results: Assemblage species richness increases with both measures of specialization at all scales. Statistically, richness appears constrained by levels of specialization, with the highest richness values only found in specialized assemblages. Richness is positively associated with specialization even after accounting for gradients in resource availability. Net primary productivity and assemblage specialization have complementary statistical effects on assemblage species richness. Contrary to expectations based on niche partitioning of local resources, the relationship between specialization and richness is steep even at coarse scales. Main conclusions: The results demonstrate that for an entire clade, totalling > 9000 species, specialization and species richness are related, at least for diverse assemblages. The strong patterns observed across scales suggest that this relationship does not solely originate from (1) limits on coexistence in presentday assemblages, or (2) increased specialization in richer assemblages imposed by species' abilities to partition ecological space. Instead, regional-scale influences on the species pool may determine much of the observed relationship between richness and specialization. Although causal attribution is not straightforward, these findings support the idea that, for the scale of our analysis, specialization may be related to the past origination of high-diversity assemblages, rather than their contemporary assembly.
An evaluation of species richness estimators for tardigrades of the Great Smoky Mountains National Park, Tennessee and North Carolina, USA
For the past 5 years we have been conducting a large-scale, multi-habitat inventory of the tardigrades in the Great Smoky Mountains National Park (U.S.A.) as part of the All Taxa Biodiversity Inventory (ATBI) (see www.dlia.org). In terrestrial habitats, we collected moss, lichen, and soil samples from 19 permanent ATBI plots, representing all major land cover types within the park. Each ATBI plot is 100 × 100 m. In each plot, when available, 16 moss samples, 16 lichen samples, and 4 soil samples were collected in paper bags and air dried in the laboratory. Specimens were isolated with LudoxAM centrifugation, and for each sample up to 50 adults plus eggs were individually mounted on microscope slides in Hoyer's medium and identified using phase contrast and DIC microscopy. Additional collections were made in the limestone caves of the Cades Cove region of the park, bird nests, and 13 different streams. To date (1-Jun-06), 589 samples have been collected, and of these 401 have been analyzed, yielding a total of 8133 identifiable tardigrades or, in some cases, species groups. A total of 73 species have been found in the park, 14 of which we believe are new to science. Seven species richness estimators have been developed to predict total species richness (see EstimateS 7.5 software, viceroy.eeb.uconn.edu/estimates), and these were evaluated by comparing predictions from half of our data to the actual numbers from the total database. The results of this comparison indicate that different estimators work best in different habitats. Using the best estimators in each habitat, EstimateS 7.5 indicates that a total of 96 species are likely to occur throughout the park. Thus, Great Smoky Mountains National Park tardigrade diversity represents 10% of the world's known tardigrade fauna.
Biodiversity of vertebrates in Argentina: patterns of richness, endemism and conservation status
Optimising conservation efforts requires an accurate record of the extant species as well as their geographic distributions. Nevertheless, most current conservation strategies start from an incomplete biodiversity inventory. Argentina has an extraordinary diversity of species, however, until now an updated inventory of its fauna has not been carried out. In this context, the main objective of this work is to present the results of the first national inventory of vertebrate species. Experts from each major vertebrate taxonomic group assembled and compiled its respective inventory. The information gathered included taxonomic rank, conservation status, endemism and geographic distribution. Species richness and representativeness were calculated for each taxonomic group, distinguishing between native, endemic and exotic, for each Argentinian province. Our results show Argentina harbours 3,303 species: 574 marine fish, 561 freshwater fish, 177 amphibians, 450 reptiles, 1,113 birds, and 428 mammals. Native species constitute 98.1% of the total taxa. The results achieved were spatially represented showing a pattern of higher richness from north to south and from east to west. Species considered as threatened account for 17.8% and 15.2% are endemic. There are five Extinct species. These results provide key information on developing strategies and public policies at the national and provincial levels and constitute a tool for the management and conservation of biodiversity.
Regional Pools and Environmental Controls of Vertebrate Richness
The species richness of local communities depends on the richness of the regional pool and the filtering processes that preclude some regional species from occurring locally. These filters may include absolute attributes of the local environment and also how representative the local environment is of the surrounding region. The latter is consistent with a species-sorting perspective, in which regional species only occupy the local habitats to which they are adapted. Here we evaluate the relative effects of local environmental conditions, environmental representativeness, and environment-independent processes on the probability of local species occurrence, given their regional presence, of birds, mammals, and amphibians worldwide. In multipredictor models, environmental representativeness is a strong independent predictor of local species occurrence probability, with a relative contribution greater than that of absolute local environmental conditions. Furthermore, we find that local occurrence probability diminishes with increased regional richness independent of the local environment. This is consistent with reduced local occupancy in richer regions, which is a pattern that could stem from a largely neutral community assembly process. Our results support the importance of both environment-independent and species-sorting processes and suggest that regional richness and environmental representativeness should be jointly used for understanding richness gradients across scales.
Mitigating the conflict between pitfall-trap sampling and conservation of terrestrial subterranean communities in caves
Subterranean habitats are known for their rich endemic fauna and high vulnerability to disturbance. Many methods and techniques are used to sample the biodiversity of terrestrial invertebrate fauna in caves, among which pitfall trapping remains one of the most frequently used and effective ones. However, this method has turned out to be harmful to subterranean communities if applied inappropriately. Traditionally, pitfall traps have been placed in caves solely on the ground. Here we present an optimized technique of pitfall trapping to achieve a balance between sampling completeness and minimal disturbance of the fauna in the cave. Monthly we placed traps for two days in two parallel sets, a ground trap and an upper one-just below the ceiling-along the cave. In the upper set, about 10% additional species were recorded compared to the ground set. Greater species diversity in the cave was the consequence of both the increased sampling effort and the amplified heterogeneity of sampled microhabitats. In caves sampled by traditional pitfall trapping, overlooked species may be a consequence of methodological biases, leading to lower biodiversity estimates. In our research, incidencebased estimations mostly surpassed abundance-based ones and predicted 95% coverage of the species richness within about two years of sampling. The sampling used contributes at the same time to both the more effective and less invasive inventory of the subterranean fauna. Thus, it may serve as an optional sampling to achieve optimal balance between required data for biodiversity and ecological studies, and nature conservation goals.
Anurans of a threatened savanna area in western Brazil
The Upper Paraguay River Basin is located in the center of South America and harbors one of the largest wetland in the world, known as Pantanal. This floodplain is surrounded by uplands, which presently have most of their area converted into pastures or monocultures, besides being poorly known scientifically. Also, most of these upland areas are considered conservation priorities. Here we present a list of anuran species from a savanna-like area (municipality of Camapuã, state of Mato Grosso do Sul, Brazil) inserted in the uplands surrounding the Pantanal floodplain, in the Upper Taquari River sub-basin, and evaluate the effectiveness of the sampling effort. Data were obtained through active searches in 22 plots in aquatic habitats, during the rainy season (from December 2009 to April 2010). We found 26 species, in four families. Although sampling effort was found to sufficiently represent the local anuran assemblage, future inventories in this region should ideally include samplings during the dry and early rainy seasons, and include both active and passive capturing methods.
Use of Approximate Inference in an Index of Completeness of Biological Inventories
To assess the completeness of a floristic or faunal inventory, one may use the ratio of the observed number of species to the \"true number\" of species (C). If the inventory is complete, C = 1. The estimate of the true number can be obtained from accumulation curves, nonparametric methods, or other techniques. We devised a simple method for computing confidence intervals (CI) for C and for evaluating the null hypothesis that the inventory is complete. The method is based on the assumptions that an estimate of the variance of the true number of species is known and that the distribution of the estimator of the true number of species is approximately normal. We applied our method to bird inventories in the Balsas Basin of Mexico. The completeness index for subtransects were lower (84.0, 85.4, and 89.9%) than for the whole transect (91.6%) (all significantly different from 100%). Thus, these particular inventories were incomplete at 2 spatial resolutions. Our method of estimating CI for C can be used to estimate species richness obtained from databases of different sites or to test the null hypothesis that an inventory derived from a database is complete. /// Para evaluar la completitud de un inventario florístico o faunístico, se puede utilizar la relación entre el número de especies observadas y el \"número verdadero\" de especies (C). Si el inventario está completo, C = 1. La estimación del número verdadero de especies se puede obtener de curvas de acumulación, métodos no paramétricos u otras técnicas. Diseñamos un método simple para calcular los intervalos de confianza (IC) para C y para evaluar la hipótesis nula de que el inventario está completo. El método se basa en los supuestos de que se conoce una estimación de la varianza del número verdadero de especies y que la distribución de un estimador de la varianza del número verdadero de especies es aproximadamente normal. Aplicamos nuestro método a inventarios de aves de la Cuenca del Balsas en México. El índice de completitud para subtransectos fue menor (84.0, 85.4 y 89.9%) que para el transecto completo (91.6%) (todos significativamente menores a 100%). Por lo tanto, estos inventarios en particular fueron incompletos en dos resoluciones espaciales. Nuestro método de estimación de IC para C puede ser utilizado para estimar la riqueza de especies obtenida de bases de datos de diferentes sitios o para probar la hipótesis nula de que un inventario derivado de una base de datos está completo.
A Large-scale, Multihabitat Inventory of the Phylum Tardigrada in the Great Smoky Mountains National Park, USA: A Preliminary Report
Issue Title: Theme The Biology of Tardigrades Selected Papers from the 9th International Symposium on Tardigrada, 28 July - 1 August, Tampa, Florida, USA An All Taxa Biodiversity Inventory (ATBI) is underway in the Great Smoky Mountains National Park (GSMNP), with the goal of attempting to identify all species of life in the 2000 km^sup 2^ park. The GSMNP is a hotbed of biodiversity, a U.N. Biosphere Reserve, and one of the largest protected, deciduous forests in the temperate world. We have completed two field seasons of work on the tardigrades in the park (2001-2002). As of July 2003, we have collected 420 samples from soil/decomposed leaf litter, lichens and mosses on trees, and stream sediment and periphyton. A few samples from caves, bird nests, and lichens/mosses on rocks were also collected. Samples were taken from within permanent plots established for the ATBI, representing the major biological communities of the GSMNP. Tardigrades were extracted from samples using centrifugation with Ludox AM(TM), individually mounted on microscope slides in Hoyer's medium, and studied with phase contrast and DIC microscopy. We have examined 1524 slides from 60 samples as of July 2003. Prior to our work, only three species of tardigrades had been previously reported from a few samples in the park. We have now recorded 42 species, 8 of which we believe may be new to science. Species richness estimates were calculated using EstimateS 6 software for each of the major tardigrade habitats. Overall, we predict that there are 47 to 76 species in the GSMNP, with generally similar species richness in soil, lichen, moss, and stream habitats. Species richness estimates were also used to determine that the number of tardigrade species was greater in mosses at breast height on trees than in mosses at the base of trees.[PUBLICATION ABSTRACT]
EXPLORING THE WILD KINGDOM WITH MARLIN
Just as the director of the National Forest Service of Paraguay opened the door to our office, the room went dark as an 8-in rubber band smacked the light switch next to his head. Even though it was a great shot we stopped celebrating. “¿¡¿Que pasa aqui?!? ¡Este oficina es un lugar de trabajo!” (“What’s happening in here? This office is a place of work!”) Well, for us this was important work! When your shot turned the lights on or off, you scored. We had devoted the entire day to this task as Peace Corps volunteers (PCVs) in Paraguay. After