6 research outputs found

    A vortex population viability analysis model for the Chacoan peccary (catagonus wagneri)

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    El quimilero o taguá (Catagonus wagneri) es una especie amenazada, endémica del Chaco Seco, para la cual disponemos de poca información. Para estimar cuantitativamente el riesgo de disminución y extinción de sus poblaciones silvestres generamos modelos de viabilidad poblacional. Con estos modelos matemáticos se pueden identificar factores naturales y antrópicos complejos que interactúan y que influyen en la persistencia y la salud de una población. Los modelos también se pueden utilizar para evaluar los efectos de diferentes estrategias de gestión, permitiendo identificar las acciones de conservación más efectivas para una población o especie. Además, estos modelos se pueden usar para identificar las necesidades de investigación debido a que ponen en evidencia los vacíos de información sobre la especie. Utilizando estos modelos, evaluamos la proyección poblacional en las condiciones actuales y en comparación con posibles variaciones existentes en el sistema. Para generar los parámetros ingresados en los modelos realizamos una reunión de especialistas y una revisión bibliográfica. Trabajó con valores de línea de base (base), mínimos (mín.) y máximos (máx.). Generamos diferentes modelos ante diferentes escenarios y testeamos la sensibilidad a la incertidumbre de cada modelo. Esto permitió establecer prioridades de investigación. Además, determinamos los tamaños mínimos de población viable considerando la incertidumbre y analizamos los posibles efectos de la caza en una población de esta especie.Fil: Leus, Kritin. International Union for Conservation of Nature. Species Survival Commission; DinamarcaFil: Altrichter, Mariana. International Union for Conservation of Nature. Species Survival Commission; Estados UnidosFil: Desbiez, Arnaud. International Union for Conservation of Nature. Species Survival Commission; BrasilFil: Camino, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Giordano, Anthony J.. S.P.E.C.I.E.S.; Estados UnidosFil: Campos Krauer, Juan Manuel. University of Florida. Department of Wildlife Ecology and Conservation; Estados Unidos. Centro Chaqueño para la Conservación y la Investigación; ParaguayFil: Brooks, Daniel M.. Houston Museum Of Natural Science; Estados UnidosFil: Thompson, Jeffrey. Consejo Nacional de Ciencia y Tecnología; ParaguayFil: Núñez Regueiro, Mauricio Manuel. University of Florida. Department of Wildlife Ecology and Conservation; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Predicting the current distribution of the chacoan peccary (catagonus wagneri) in the gran Chaco

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    The Chacoan peccary (Catagonus wagneri), or Tagua, an endemic species living in the Chaco eco¬region, is endangered by highly increasing deforestation rates across the region, particularly in the last decade. This situation highlights the need to better understand the current distribution of the species, as well as how environmental conditions affect habitat suitability. This study predicts the distribution of the Chacoan peccary and evaluates the current environmental conditions in the Chaco for this species. Using six environmental variables and 177 confirmed occurrence records (from 2000 to 2015) provided by researchers, we developed a Species Distribution Model (SDM) applying the Maxent algorithm. The final model was highly accurate and significant (p < 0.001; AUC 0.860 ± 0.0268; omission error 1.82 %; post¬hoc validation of omission error using independent presence¬only records 1.33 %), predicting that 46.24 % of the Chaco is suitable habitat for the Chacoan peccary, with the most important areas concentrated in the middle of Paraguay and northern Argentina. Land cover, isothermality and elevation were the variables that better explained the habitat suitability for the Chacoan peccary. Despite some portions of suitable areas occurring inside protected areas, the borders and the central portions of suitable areas have recently suffered from intensive deforestation and development, and most of the highly suitable areas for the species are not under protection. The results provide fundamental insights for the establishment of priority Chacoan peccary conservation areas within its rangeFil: Paschoaletto Micchi, Katia Maria. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz Esalq; Brasil. Conservation Breeding Specialist Group Brazilian network; BrasilFil: Silva Angelieri, Cintia Camila. Universidade Do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz Esalq; BrasilFil: Altrichter, Mariana. Prescott College; Estados UnidosFil: Desbiez, Arnaud. Royal Zoological Society of Scotland. Edimburgo; Reino Unido. Conservation Breeding Specialist Group Brazilian network; BrasilFil: Yanosky, Alberto. Asociación Guyra Paraguay. Asunción; ParaguayFil: Campos Krauer, Juan Manuel. Centro Chaqueño para la Conservación y la Investigación; ParaguayFil: Torres, Ricardo Jose. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Camino, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Cabral, Hugo. Asociación Guyra Paraguay. Asunción; ParaguayFil: Cartés, José. Asociación Guyra Paraguay. Asunción; ParaguayFil: Cuellar, Rosa Leny. Fundación Kaa Iya; BoliviaFil: Gallegos, Marcelo. Secretaría de Ambiente de la Provincia de Salta. Programa Guardaparques; ArgentinaFil: Giordano, Anthony J.. No especifica;Fil: Decarre, Julieta. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; ArgentinaFil: Maffei, Leonardo. Wildlife Conservation Society. Lima; PerúFil: Neris, Nora. Universidad Nacional de Asunción; ParaguayFil: Saldivar Bellassai, Silvia. Itaipu Binacional; ParaguayFil: Wallace, Robert. Wildlife Conservation Society. New York; Estados UnidosFil: Lizarraga, Leónidas. Delegación Regional Noroeste. Sistema de Información de Biodiversidad de la Administración de Parques Nacionales. Salta; ArgentinaFil: Thompson, Jeffrey. Universidad Nacional de Asunción; ParaguayFil: Velilla, Mariela. Universidad Nacional de Asunción; Paragua

    Landscape ecology of the capybara (Hydrochoerus hydrochaeris) in the Chaco region of Paraguay

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    Doctor of PhilosophyDepartment of BiologySamantha WiselyHabitat fragmentation and destruction are the most ubiquitous and serious environmental threats confronting the long-term survival of plant and animal species worldwide. However, some native or exotic species can take advantages of these alterations and expand their range, placing endemic species at risk of extinction by changing the composition of biotic communities and altering ecosystem. Capybara (Hydrochoerus hydrochaeris) are a widely distributed rodent throughout most of South and Central America, but restricted to areas of standing water. As the Gran Chaco ecosystem of Paraguay has been converted from dry tropical forest to pastureland, I hypothesized that this habitat alteration created potential for invasion by capybara into newly fragmented areas. I used ecological niche modeling to generate hypotheses about how the distribution of capybara has been affected by land use change, and tested those hypotheses with phylogeographic analyses. To understand the mechanisms that have allowed the invasion, I investigated home range, habitat use and thermoregulation of capybara via radiotelemetry in a deforested area in which capybara had recently invaded. Genetic analyses confirm a rapid range expansion scenario with evidence of secondary contact between two distinct phylogroups which had previously been disjunct. Modeling results indicated that conversion of forest to pastureland allowed the expansion to occur. Capybara selected water significantly more than it was available to them, and avoided shrub forest. I found a significant positive correlation between body temperature and distance from water, and a significant negative correlation between distance from water and Chaco ambient temperature. Capybara proximity to water appeared to be tightly linked to body thermoregulation. These results suggest that although capybara have expanded into the Chaco forest as it is converted to pastureland, the presence of permanent water sources in those pastures are the mechanism that allow capybara to persist in this habitat. This is the first study to characterize capybara in a xeric habitat without a year round water source, and scarce natural grasslands. My results show how anthropogenic habitat modification has allowed capybara to thrive. Understanding how capybara invade and utilize the deforested Central Dry Chaco will provide valuable information for the future management of the species and the Chaco ecosystem

    Situación de conservación del pecarí del Chaco o tagua (Catagonus wagneri): distribución, aptitud de hábitat y viabilidad poblacional

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    El pecarí del Chaco conocido localmente en Paraguay como tagua (Catagonus wagneri) es una especie en peligro de extinción endémica del Chaco Americano, cuya situación se mantiene en deterioro como consecuencia de la pérdida y transformación de su hábitat y de la caza excesiva en toda su área de distribución. Este trabajo presenta los resultados obtenidos y la información recopilada durante el taller “Estrategia Regional para la Conservación del Tagua” realizado en la ciudad de Asunción del Paraguay durante marzo del año 2016. En base a datos biológicos, parámetros poblacionales, puntos de presencia de la especie, datos de deforestación y cacería, describimos la situación de la especie en cada país, modelamos la distribución de la especie y aptitud del hábitat con el programa Maxent y los efectos de la cacería en la viabilidad poblacional con el programa Vortex. La ecoregión Chaqueña posee una de las mayores tasas de deforestación mundial, debido a la expansión de la ganadería y de la agricultura generando como consecuencia una pérdida de hábitat que representa la mayor amenaza para la supervivencia de la especie. En Paraguay, la deforestación en el centro del Chaco amenaza las poblaciones remanentes de tagua. En Argentina la rápida degradación de la vegetación nativa y las falencias en la implementación de normativas que manejan el bosque indican que la situación del tagua es precaria. La información disponible para la especie en Bolivia se restringe al Parque Nacional Kaa-Iya, sin embargo, la aptitud del hábitat dentro del parque y en el resto del Chaco boliviano es alta lo cual indicaría que el tagua podría estar en mejores condiciones de conservación que en los otros dos países. Los modelos de aptitud del hábitat muestran que la cobertura del suelo, la isotermalidad y la elevación son las variables mejor correlacionadas con la presencia de la especie. Aproximadamente 46% de la superficie del Gran Chaco sería apta para la especie, y únicamente el 12% del área con la mejor aptitud está incluido en un sistema oficial de protección. Según el modelo de viabilidad poblacional se requieren poblaciones mínimas de entre 1000 y 1300 individuos, en ausencia de amenazas de origen humano (ej.: caza), para que la especie sobreviva por lo menos 100 años sin perder variación genética. Con tasas anuales de cacería del 20% y del 10% la especie debería extinguirse en 20 y 100 años respectivamente. Sin embargo, una cacería que coseche el 5% de la población podría ser sustentable, si no hubiera pérdida de hábitat. La dramática conversión de superficies naturales sumada a la reducida superficie de áreas aptas protegidas y a la presión de caza determina que la conservación del tagua a largo plazo se vea amenazada. Es necesario continuar con trabajos de investigación que permitan obtener datos de calidad para posibilitar la gestión y manejo sostenible de la especie. Es indispensable que se revisen las políticas de uso del suelo y se implementen controles a la deforestación masiva que ponen en peligro el tagua y el resto de la biodiversidad del Chaco.The Chacoan peccary known locally in Paraguay as tagua (Catagonus wagneri) is an endangered species endemic to the Gran Chaco. Its situation continues to deteriorate as a consequence of habitat loss and transformation, as well as excessive hunting throughout its range. This study presents results and information obtained during the workshop “Regional strategy for the conservation of the tagua”, held in Asunción, Paraguay, in March 2016. Using population parameters as well as biological, species presence, hunting and deforestation data, we describe the conservation status in each country, model the species distribution and habitat suitability using Maxent software and the effects of hunting on population viability using Vortex software. The Chaco region has one of the highest deforestation rates in the world due to the expansion of agriculture and pastures, leading to habitat loss, which is currently the largest threat to the species survival. In Paraguay, high deforestation in the center of the Chaco threatens the remnant tagua populations. In Argentina, rapid degradation of the native vegetation and deficient implementation of land management legislation indicate a precarious situation for the species. The information about the species in Bolivia is restricted to the Kaa-Iya National Park, however, high habitat suitability in the park and outside indicate that the species may have a better conservation status than in the other countries. Habitat suitability models show that land cover, isothermality and elevation are the variables that best explain the species’ presence. Approximately 46% of the Gran Chaco is suitable for the species, but only 12% of the area with high suitability is under some type of protection. According to the population viability model done with the software Vortex, a minimum population of 1000 to 1300 individuals is required, with no human threats, to ensure that the species will survive for 100 years without losing genetic diversity. With annual hunting rates of 20% and 10% of the population, the species would go extinct in 20 and 100 years respectively, however, a harvest rate of 5% could be sustainable in the absence of habitat loss. The dramatic conversion of natural habitat, in addition to the small area that is protected and the persistence of illegal hunting threaten the future of the species. Further research is required to generate the data necessary to manage the conservation and potential use of the species. Land use policies must be revised, and the deforestation and illegal hunting that jeopardize the tagua and the entire Chaco biodiversity must be controlled.Fil: Altrichter, Mariana. Prescott University; Estados Unidos. Iucn; SuizaFil: Saldivar-Ballesai Silvia. Itaipu; ParaguayFil: Decarre, Julieta. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales; ArgentinaFil: Camino, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Campos Krauer Juan. Centro Chaqueño Para la Conservación y la Investigació; ParaguayFil: Yanosky Alberto. Guyra Paraguay; ParaguayFil: Leus Kristin. Iucn; SuizaFil: Ferraz Katia. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Silva Angelieri Cintia Camila. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Desbiez Arnaud. Iucn; SuizaFil: Cuellar Rosa Leny. Fundación Kaa Iyá; BoliviaFil: Cartés José. Guyra Paraguay; ParaguayFil: Giordano Anthony. S.p.e.c.i.e.s; Estados UnidosFil: Thompson Jeffrey. Consejo Nacional de Ciencias y Tecnología (conacyt).; ParaguayFil: Velilla Marianela. Guyra Paraguay; ParaguayFil: Torres Ricardo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Neris Nora. Secretaría de Ambiente; ParaguayFil: Cabral Hugo. Guyra Paraguay; Paragua

    NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

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    Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data

    NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

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    Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data
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