Identification of limiting climatic and geographical variables for the distribution of the tortoise Chelonoidis chilensis (Testudinidae): a baseline for conservation actions

Background. Just as for most other tortoise species, the once common Chaco tortoise, Chelonoidis chilensis (Testudinidae), is under constant threat across it distribution in Argentina, Bolivia and Paraguay. Despite initial qualitative description of the species distribution and further individual reports of new locations for the species, there is no description of the species distribution in probabilistic terms. With this work we aim to produce an updated predictive distribution map for C. chilensis to serve as a baseline management tool for directed strategic conservation planning.Methods. We fitted a spatially expanded logistic regression model within the Bayesian framework that accounts for uncertainty on presence-only and generated pseudo-absence data into the parameter estimates. We contrast the results with reported data for the national networks of protected areas to assess the inclusion of the species in area-based conservation strategies.Results. We obtained maps with predictions of the occurrence of the species and reported the model's uncertainty spatially. The model suggests that potential suitable habitats for the species are continuous across Argentina, West Paraguay and South Bolivia, considering the variables, the scale and the resolution used. The main limiting variables were temperature-related variables, and precipitation in the reproductive period.Discussion. Given the alarming low density and coverage of protected areas over the distribution area of C. chilensis, the map produced provides a baseline to identify areas where directed strategic conservation management actions would be more efficient for this and other associated species

Thermal Biology of Zoo-Housed Chelonoidis chilensis: Determining the Activity Pattern and Estimating Selected and Critical Maximum Temperature

Ectothermic animals depend on environmental temperature to regulate their body temperature. The Chaco Tortoise (Chelonoidis chilensis) is widespread in South America; however, populations are threatened mainly because of the pet trade. We described the activity pattern of C. chilensis relative to environmental temperature under semi-natural conditions in a zoo enclosure. We also estimated thermal parameters under controlled laboratory conditions: selected temperature (Tsel) and critical maximum temperature (CTmax) between sex and size indicators. In the enclosure, 81% of the observations were from inactive tortoises and 19% from active tortoises. Tortoises were active over a wide thermal range (12.0°?38.0° C) and Tsel was 34.4° ± 0.3° C (mean ± standard error), with no significant differences among sizes or between sexes. Heavier tortoises spent significantly more time at the lowest temperature than lighter ones. The range of CTmax was 36.3°?42.0° C and this parameter was inversely related to tortoise length but did not differ between sexes. The results suggest a wide thermal range in C. chilensis, dependence of thermal behavior on body size but not on sex, and a wider range of body temperatures in smaller individuals than in larger ones. Knowing the parameters that influence thermoregulation contributes to the improvement of management strategies under semi-natural conditions, which, in turn, can be extrapolated to wild populations.Fil: Buteler, Candela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Zoología Aplicada; ArgentinaFil: Lábaque, María Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Leynaud, Gerardo Cristhian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Zoología Aplicada; Argentin

Thermal Biology of Zoo-Housed Chelonoidis chilensis: Determining the Activity Pattern and Estimating Selected and Critical Maximum Temperature

Ectothermic animals depend on environmental temperature to regulate their body temperature. The Chaco Tortoise (Chelonoidis chilensis) is widespread in South America; however, populations are threatened mainly because of the pet trade. We described the activity pattern of C. chilensis relative to environmental temperature under semi-natural conditions in a zoo enclosure. We also estimated thermal parameters under controlled laboratory conditions: selected temperature (Tsel) and critical maximum temperature (CTmax) between sex and size indicators. In the enclosure, 81% of the observations were from inactive tortoises and 19% from active tortoises. Tortoises were active over a wide thermal range (12.0°?38.0° C) and Tsel was 34.4° ± 0.3° C (mean ± standard error), with no significant differences among sizes or between sexes. Heavier tortoises spent significantly more time at the lowest temperature than lighter ones. The range of CTmax was 36.3°?42.0° C and this parameter was inversely related to tortoise length but did not differ between sexes. The results suggest a wide thermal range in C. chilensis, dependence of thermal behavior on body size but not on sex, and a wider range of body temperatures in smaller individuals than in larger ones. Knowing the parameters that influence thermoregulation contributes to the improvement of management strategies under semi-natural conditions, which, in turn, can be extrapolated to wild populations.Fil: Buteler, Candela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Zoología Aplicada; ArgentinaFil: Lábaque, María Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Leynaud, Gerardo Cristhian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Zoología Aplicada; Argentin

High-pressure synthesis and structural behavior of sodium orthonitrate Na3NO4

Sodium orthonitrate (Na3NO4) is an unusual phase containing the first example of isolated tetrahedrally bonded NO43- groups. This compound was obtained originally by heating together mixtures of Na2O and NaNO3 for periods extending up to > 14 days in evacuated chambers. Considering the negative volume change between reactants and products, it was inferred that a high-pressure synthesis route might favor the formation of the Na3NO4 compound. We found that the recovered sample is likely to be a high-pressure polymorph, containing NO43- groups as evidenced by Raman spectroscopy. The high-pressure behavior of Na3NO4 was studied using Raman spectroscopy and synchrotron X-ray diffraction in a diamond anvil cell above 60 GPa. We found no evidence for major structural transformations, even following laser heating experiments carried out at high pressure, although broadening of the Raman peaks could indicate the onset of disordering at higher pressure

Breeding-site selection by red-belly toads, Melanophryniscus stelzneri (Anura: Bufonidae), in Sierras de Córdoba, Argentina

Differences among wetlands can have important consequences on reproductive success of amphibians; thereforehabitat selection is expected to be of particular importance for anurans inhabiting heterogeneous environments. To investigateif the red-belly toad (Melanophryniscus stelzneri; Anura: Bufonidae) uses available habitats differentially and to determine themain factors influencing the use of certain water bodies as breeding habitat, we surveyed 30 spawning sites used by red-bellytoads, and 30 adjacent unused sites, in an area of the Sierras of Córdoba, Argentina. We evaluated the relative importanceof morphological and biotic features of ponds, and the presence of other organisms within the water body on the use ofponds as breeding sites by red-belly toads. Eight habitat variables related to important water body features were recorded andwere used to fit a habitat selection model with GLM. Red-belly toads presented a positive selection to mallines, a wetlandcharacteristic of the Sierras of Córdoba. They were associated with small, shallow ephemeral ponds with muddy banks and ahigh percent of vegetation cover. In general, the ponds used did not host other anuran species or potential predators. Breedingsite selection by red-belly toads is largely consistent with records for other species of the genus in other parts of Argentina.Fil: Pereyra, Laura Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Lescano, Julián Norberto. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leynaud, Gerardo Cristhian. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Functional traits reveal environmental constraints on amphibian community assembly in a subtropical dry forest

The relationships between functional traits and environmental gradients are useful to identify different community assembly processes. In this work, we used an approach based on functional traits to analyse if changes in hydroperiod and tree covers of ponds are relevant for local amphibian community assembly processes. Ephemeral ponds with low vegetation cover are expected to impose constraints on different species with particular trait combinations and, therefore, to exhibit communities with lower functional diversity than more stable ponds with greater tree cover. Sampling was conducted in 39 temporary ponds located along vegetation and hydroperiod gradients in the most arid portion of the Chaco ecoregion. Seven functional traits were measured in each species present in the regional pool. Associations between these traits and environmental gradients were detected using multivariate ordination techniques and permutation test (RLQ and fourth-corner analyses respectively). Functional diversity indices were then calculated and related to variations in the environmental gradients. The results obtained allowed us to identify different sets of traits associated with hydroperiod and tree cover, suggesting that these environmental variables are relevant for structuring amphibian communities according to interspecific variations in functional traits from both, larval and adult stages. Contrary to our expectations, communities associated with more stable ponds and with greater tree cover exhibited lower functional diversity than expected by chance (and were the ponds with highest species richness). This result indicates that the reduction in relative importance of environmental restrictions imposed by a very short hydroperiod and the lack of tree cover, favours different species of the regional pool that are similar in several functional traits. Accordingly, communities associated with stable ponds with high tree cover exhibited high functional redundancy.Fil: Lescano, Julián Norberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Miloch, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Leynaud, Gerardo Cristhian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Evaluating behavior and enclosure use of Zoo-housed broadsnouted Caiman (Caiman latirostris): A case study in the Zoo of Córdoba (Argentina)

Los zoológicos son ambientes que permiten avanzar en la investigación de diversas especies, particularmente aquellas difíciles de observar en vida silvestre. Los estudios de comportamiento en estos ambientes proveen información importante acerca del estado de bienestar de los animales. Aquí describimos los comportamientos de una población de siete Yacarés Overos (Caiman latirostris) compuesta por machos y hembras de distintas edades. Evaluamos la asociación de las frecuencias de comportamientos con atributos individuales (sexo y clase etaria) y con variables ambientales (temporada, hora del día y temperatura ambiente media). Calculamos el Índice de Dispersión de la Participación para estimar el uso del espacio en relación a atributos individuales y variablesambientales. Adicionalmente, evaluamos la adecuación del habitáculo y medidas de manejo mediante el análisis de las Cinco Libertades. Los resultados mostraron mayor frecuencia de comportamientos acuáticos en adultos que en subadultos, lo cual podría reflejar un cambio ontogenético comportamental o bien ser una consecuencia de la jerarquía de dominancia. Hubo pocas diferencias comportamentales entre sexos. Los comportamientos acuáticos estuvieron asociados a temperaturas bajas, pudiendo atribuirse al comportamiento de termorregulación. Los resultados también mostraron un movimiento diario desde el agua a la mañana hacia la tierra al mediodía y tarde. Registramos una alta tasa de comportamientos agonistas y se discutieron las posibles causas e implicancias. El uso del espacio fue reducido, con zonas escasamente utilizadas o no utilizadas, y marcada variabilidad entre individuos. Finalmente, un 53% de las recomendaciones de manejo para esta especie se cumplieron en la población en estudioLos zoológicos son ambientes que permiten avanzar en la investigación de diversas especies, particularmente aquellas difíciles de observar en vida silvestre. Los estudios de comportamiento en estos ambientes proveen información importante acerca del estado de bienestar de los animales. Aquí describimos los comportamientos de una población de siete Yacarés Overos (Caiman latirostris) compuesta por machos y hembras de distintas edades. Evaluamos la asociación de las frecuencias de comportamientos con atributos individuales (sexo y clase etaria) y con variables ambientales (temporada, hora del día y temperatura ambiente media). Calculamos el Índice de Dispersión de la Participación para estimar el uso del espacio en relación a atributos individuales y variables ambientales. Adicionalmente, evaluamos la adecuación del habitáculo y medidas de manejo mediante el análisis de las Cinco Libertades. Los resultados mostraron mayor frecuencia de comportamientos acuáticos en adultos que en subadultos, lo cual podría reflejar un cambio ontogenético comportamental o bien ser una consecuencia de la jerarquía de dominancia. Hubo pocas diferencias comportamentales entre sexos. Los comportamientos acuáticos estuvieron asociados a temperaturas bajas, pudiendo atribuirse al comportamiento de termorregulación. Los resultados también mostraron un movimiento diario desde el agua a la mañana hacia la tierra al mediodía y tarde. Registramos una alta tasa de comportamientos agonistas y se discutieron las posibles causas e implicancias. El uso del espacio fue reducido, con zonas escasamente utilizadas o no utilizadas, y marcada variabilidad entre individuos. Finalmente, un 53% de las recomendaciones de manejo para esta especie se cumplieron en la población en estudio.Fil: Prystupczuk, Lilen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Leynaud, Gerardo Cristhian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Lábaque, María Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentin

Morphology, phylogeny and taxonomy of South American bothropoid pitvipers (Serpentes, Viperidae)

South American bothropoids comprise a monophyletic and greatly diverse group of pitvipers that were initially included in the genus Bothrops and later assigned to five genera. Until recently, most phylogenetic analyses of bothropoids used exclusively mitochondrial DNA sequences, whereas few of them have included morphological traits. Moreover, the systematic affinities of some species remain unclear. In this study, we performed a parsimony analysis of morphological data obtained from the examination of 111 characters related to lepidosis, colour pattern, osteology, and hemipenial morphology of 35 of the 48 species that compose the bothropoid group. The morphological data analysed contain novel information about several species, including the incertae sedis. Morphology was analysed separately and combined with 2393 molecular characters obtained from published sequences of four mitochondrial genes. Five characters of the ecology were also included. A sensitivity analysis was performed using different weighting criteria for the characters. The congruence among different sources of evidence was evaluated through partitioned and total evidence analyses, the analyses of reduced datasets and the use of incongruence length difference test. With few exceptions, results showed groups of species similar to those obtained in previous studies; however, incongruences between morphological and molecular characters, and within the molecular partition, were revealed. This conflict affects the relationship between particular groups of species, leading to alternative phylogenetic hypotheses for bothropoids: hierarchical radiation or two major lineages within the group. The results also showed that Bothrops sensu stricto is paraphyletic. We discuss previous taxonomic approaches and, considering both phylogenetic hypotheses, we propose an arrangement that rectifies the paraphyly of Bothrops: maintaining Bothrocophias, assigning Bothrops andianus to this genus; and recognising the sister clade as Bothrops, synonymising Bothriopsis, Bothropoides and Rhinocerophis.Fil: Carrasco, Paola Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Mattoni, Camilo Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Diversidad Animal I; ArgentinaFil: Leynaud, Gerardo Cristhian. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Scrocchi Manfrini, Gustavo Jose. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin