Livestock and the functional habitat of vicuñas in Ecuador : a new puzzle

Includes supplementary Appendix S1.Whether interactions between wildlife and livestock are competitive or facilitative is context dependent. Intermediary factors that explain how context (seasonal or regional characteristics of the ecological community) affects these interactions are rarely reported. We compared activity time and density in vicuñas (Vicugna vicugna) introduced into the Chimborazo Faunal Production Reserve (CFPR), Ecuador, to describe how they interact with livestock. We compared vicuña density in wetlands and uplands (two landscape structures) with and without livestock (two conditions) using an isodar approach. We measured, over two seasons, vicuña forage abundance, composition, preference and accessibility, time vicuñas spent vigilant, and their flight distances on approach. We tested optimal foraging theory relating to the hypothesis that time mediates behavior, and found that vicuñas were no less frequently vigilant, nor were flight distances greater, during a wet season or in habitats of greater forage abundance and accessibility. We also found no evidence that vicuña behavior was density dependent; instead, we found that more time was spent vigilant by vicuñas when they foraged near livestock in rainy regions during the dry season. Although forage abundance was similar throughout CFPR during a dry season, better forage quality in areas occupied by livestock may constitute an effect of their facilitating vicuñas. A puzzling finding, because it was not explained by any of the other variables we measured, was that at low densities vicuñas selected habitat irrespective of livestock, and where their density was higher, it was doubly so adjacent to livestock. We conclude that in the CFPR, spatial heterogeneity in habitat quality determines the interactions between livestock and vicuñas. To support recommendations that minimize competition between wildlife and livestock, and to expand on descriptions of the contexts that determine the direction of species interactions, future study may require a wider sampling of the densities of sympatric large herbivores in general, and, in the CFPR, a closer resolution of spatial heterogeneity in forage plant quality

Revisión de la metodología utilizada para categorizar especies amenazadas de la herpetofauna argentina

Revisamos el método utilizado para determinar especies amenazadas en la Argentina, con los objetivos de: (1) que pueda ser empleado consistentemente por diferentes personas reduciendo la subjetividad, (2) brindar una guía sobre cómo evaluar los factores que conducen al riesgo de extinción, (3) proporcionar a los usuarios de listas rojas una mejor comprensión sobre el proceso de categorización, (4) ofrecer un sistema que facilite comparaciones entre taxones. Respecto al método anterior se proponen 11 modificaciones, además de la reducción del número de variables a seis, todas relevantes para definir la vulnerabilidad de las especies incluyendo: (1) Distribución y grado de endemismo; (2) Rareza ecológica; (3) Efectos humanos, (4) Potencial reproductivo; (5) Tamaño; (6) Rareza demográfica (abundancia). Se proponen modificaciones en el rango de valores de las variables (a veces siguiendo umbrales de IUCN) y se brindan valores umbrales teóricos orientativos para las categorías. Por primera vez en Argentina se explicitan mecanismos para minimizar sesgos debidos a subjetividad e incertidumbre en el proceso de categorización, que incluyen: (1) El consenso de múltiples evaluadores; (2) El uso de una guía de entrenamiento; (3) Sugerencias para manejar la incertidumbre.We review the method used to determine endangered species in Argentina, with the objectives of: (1) that can be used consistently by different people reducing subjectivity, (2) provide guidance on how to assess the factors that affect the risk of extinction, (3) provide users of red lists a better understanding of the categorization process, (4) provide a system that will facilitate comparisons across taxa. Over the previous method proposed 11 amendments in addition to reducing the number of variables to 6, all relevant to define the vulnerability of species including: (1) Distribution and degree of endemism, (2) Ecological rarity, (3) Human effects, (4) Reproductive potential, (5) Size, (6) Demographic rarity (abundance). The amendments are proposed in the range of values of the variables (sometimes following thresholds of IUCN) and provide theoretical guidance thresholds for the categories. For the first time in Argentina we made explicit the mechanisms to minimize bias due to subjectivity and uncertainty in the categorization process, including: (1) The consensus of multiple reviewers, (2) The use of a training guide, (3) Suggestions to manage uncertainty.Asociación Herpetológica Argentina (AHA

Categorización del estado de conservación de las serpientes de la República Argentina

A más de una década de la primera Lista Roja de herpetofauna amenazada propuesta por la Asociación Herpetológica Argentina (AHA 2000), se recategorizaron las serpientes a partir de nueva información taxonómica, biogeográfica y bio-ecológica, además de modificaciones metodológicas respecto a la evaluación anterior. Mediante la participación de 18 especialistas de toda la Argentina se reevaluaron 136 taxones de serpientes (130 en la anterior) incluyendo varios cambios taxonómicos (8 taxones nuevos para Argentina y 2 sinonimizados), obteniéndose como resultado la inclusión de 49 especies en la lista roja (5 En Peligro, 17 Amenazadas, 27 Vulnerables), 15 Insuficientemente Conocidas y 72 No Amenazadas. En relación con la categorización anterior de la AHA: un taxón descendió de Vulnerable a No Amenazado, 11 No amenazados y 4 Insuficientemente Conocidos fueron elevados a distintas categorías de amenaza, 7 taxones Vulnerables fueron elevados a Amenazados, un taxón fue elevado de Amenazado a En Peligro. De 8 taxones no evaluados en 2000, uno categorizó No Amenazado, 4 Insuficientemente Conocidos, uno Vulnerable y 2 Amenazados. Estas modificaciones son el resultado de: (1) Mayor información sistemática, biogeográfica y bio-ecológica disponible para la evaluación; (2) Cambios en cuanto a las presiones antrópicas sobre las especies o sus hábitats; (3) Modificaciones metodológicas que incluyeron instructivos para aplicar los conceptos, la discusión y consenso entre especialistas y el análisis de las incertidumbres.After more than a decade from the first red list of threatened herpetofauna proposal by the Asociación Herpetológica Argentina (2000), we re-categorized snakes from new taxonomic, biogeographical and bio-ecological information as well as methodological changes in the former evaluation. Through the participation of 18 specialists from all over Argentina, 136 taxa of snakes (130 in the previous) were re-evaluated including several taxonomic changes (8 new taxa added to Argentina, and 2 sinonimies). The results were the inclusion of 49 species in the red list (5 Endangered, 17 Threatened, 27 Vulnerable), 15 Insufficiently Known and 72 Not Threatened. Compared to the former categorization of the AHA: one taxon descended from Vulnerable to Not Threatened, 11 Not Threatened and 4 Insufficiently Known were elevated to different categories of threat, 7 taxa were elevated from Endangered to Vulnerable, one from Vulnerable to Endangered. From the 8 taxa not evaluated in 2000, one categorized Not Threatened, 4 Insufficiently Known, one Vulnerable, and 2 Threatened. These changes are the result of: (1) increased systematic, biogeographical and bio- ecological information available for the evaluation, (2) Changes in human pressures on the species or their habitats, (3) methodological changes that included recommendations to apply concepts, discussion and consensus among specialists and the analysis of uncertainties.Asociación Herpetológica Argentina (AHA

Histopathological Findings Related to ORISE™ Injectable Submucosa Lifting Agent Used in the Endoscopic Mucosal Resection of Bowel Neoplasms: A Review of Three Cases

The use of nonsaline injectable lifting agents is now routine in the performance of endoscopic mucosal resection of bowel neoplasms (EMR). These agents are used to elevate the mucosa from the muscularis propria and permit more a complete resection of the lesion while mitigating risk of possible thermal injury to the bowel wall and thus preventing perforation. After injection, these new agents, which are replacing normal saline, often remain present in the tissues for some time following the procedure and may be identified in the resection specimens where they may mimic a number of other conditions such as mucin pools, lymphangiomas, granulomatous inflammation, and amyloid deposition. We describe the histological findings associated with the use of nonsaline injectable mucosal lifting agents. Awareness of these agents and their associated artefact may reduce misdiagnosis or the use of unnecessary ancillary studies and highlights the importance of proving relevant clinical information on submission of specimens for pathological examination

Temperate snake community in South America: is diet determined by phylogeny or ecology?

Communities are complex and dynamic systems that change with time. The first attempts to explain how they were structured involve contemporary phenomena like ecological interactions between species (e.g., competition and predation) and led to the competition-predation hypothesis. Recently, the deep history hypothesis has emerged, which suggests that profound differences in the evolutionary history of organisms resulted in a number of ecological features that remain largely on species that are part of existing communities. Nevertheless, both phylogenetic structure and ecological interactions can act together to determine the structure of a community. Because diet is one of the main niche axes, in this study we evaluated, for the first time, the impact of ecological and phylogenetic factors on the diet of Neotropical snakes from the subtropical-temperate region of South America. Additionally, we studied their relationship with morphological and environmental aspects to understand the natural history and ecology of this community. A canonical phylogenetical ordination analysis showed that phylogeny explained most of the variation in diet, whereas ecological characters explained very little of this variation. Furthermore, some snakes that shared the habitat showed some degree of diet convergence, in accordance with the competition-predation hypothesis, although phylogeny remained the major determinant in structuring this community. The clade with the greatest variability was the subfamily Dipsadinae, whose members had a very different type of diet, based on soft-bodied invertebrates. Our results are consistent with the deep history hypothesis, and we suggest that the community under study has a deep phylogenetic effect that explains most of the variation in the diet

<i>Tomodon ocellatus</i> Duméril, Bibron & Duméril, 1854 : Falsa yarará caracolera pampeana

Habita en pastizales de la ecorregión Pampeana y del Espinal (Arzamendia y Giraudo 2004; Giraudo, 2001) que poseen deficiencias en áreas protegidas con el 0,05% y el 0,03% respectivamente (Brown y Pacheco, 2006) y tienen una enorme pérdida de hábitat por cultivos, forestaciones y urbanización. No registrada durante 15 años de muestreos en Santa Fe que tiene el 80% de su superficie cultivada, gran parte de su distribución en Buenos Aires, Entre Ríos y Córdoba se perdió por urbanización y expansión agrícola. En los últimos años solamente registrada en pastizales conservados de Entre Ríos y Corrientes (Etchepare, Giraudo y Arzamendia obs. pers.). Especialista en hábitat y alimentación (moluscos terrestres sin concha), vivípara (Gallardo, 1972, 1977; Cei 1993) con bajo potencial reproductivo (8 crías) y bianual o multianual como otros Tachymenini (Bellini, obs. pers.). Adicionalmente afectada por atropellamientos y eliminación por personas debido a su coloración mimética con Bothrops. Su rareza ecológica, bajo potencial reproductivo y la creciente presión humana que han modificando gran parte de hábitat, justifican su cambio de categoría a Vulnerable.Fichas de los taxones.Facultad de Ciencias Naturales y MuseoAsociación Herpetológica Argentin

<i>Tomodon ocellatus</i> Duméril, Bibron & Duméril, 1854 : Falsa yarará caracolera pampeana

Habita en pastizales de la ecorregión Pampeana y del Espinal (Arzamendia y Giraudo 2004; Giraudo, 2001) que poseen deficiencias en áreas protegidas con el 0,05% y el 0,03% respectivamente (Brown y Pacheco, 2006) y tienen una enorme pérdida de hábitat por cultivos, forestaciones y urbanización. No registrada durante 15 años de muestreos en Santa Fe que tiene el 80% de su superficie cultivada, gran parte de su distribución en Buenos Aires, Entre Ríos y Córdoba se perdió por urbanización y expansión agrícola. En los últimos años solamente registrada en pastizales conservados de Entre Ríos y Corrientes (Etchepare, Giraudo y Arzamendia obs. pers.). Especialista en hábitat y alimentación (moluscos terrestres sin concha), vivípara (Gallardo, 1972, 1977; Cei 1993) con bajo potencial reproductivo (8 crías) y bianual o multianual como otros Tachymenini (Bellini, obs. pers.). Adicionalmente afectada por atropellamientos y eliminación por personas debido a su coloración mimética con Bothrops. Su rareza ecológica, bajo potencial reproductivo y la creciente presión humana que han modificando gran parte de hábitat, justifican su cambio de categoría a Vulnerable.Fichas de los taxones.Facultad de Ciencias Naturales y MuseoAsociación Herpetológica Argentin

Results of a phylogenetic ordination analysis using canonical correspondence analysis for the diets of 25 species in a snake community in temperate South America.

<p>Clades are ranked by the amount of variation explained at each node. Percentage of the variation explained (relative to total unconstrained variation) and <i>F</i>- and <i>P</i>-values for each variable are given (9,999 permutations were used) for each main matrix. Note that no groups used for variable selection of variable yielded individual <i>P</i>≤0.05.</p><p>Results of a phylogenetic ordination analysis using canonical correspondence analysis for the diets of 25 species in a snake community in temperate South America.</p