Vertebrados Terrestres

La disminución o incluso extinción de poblaciones de especies de vida silvestre tiene sus principales causas en una serie de problemas como la reducción del área de cobertura vegetal efectiva, la modificación de factores bióticos y abióticos por cambio de uso de suelo y el tráfico ilegal de fauna silvestre. Al contrario de una visión proteccionista, que se ha reflejado en el establecimiento de áreas que no pueden ser sometidas a ningún tipo de aprovechamiento, actualmente se reconoce la existencia de esquemas que permiten la conservación bajo un manejo y uso adecuado de los recursos, y se plantea la necesidad de incluir desde el principio el análisis de los factores socioeconómicos que harán posible la operatividad de las áreas de conservación. Por lo anterior es indispensable formular estrategias de monitoreo biológico que aporten información sobre la presencia y abundancia de las especies y que respalden acciones de conservación y uso sustentable de la biodiversidad. El monitoreo participativo de la biodiversidad ha demostrado ser una estrategia que aumenta notablemente el interés local y regional por la conservación y el adecuado uso de recursos naturales. La guía que usted tiene en las manos es resultado de un proyecto impulsado por Conservación Biológica y Desarrollo Social, A. C., que busca formar una red de monitoreo participativo de la biodiversidad en México. Este proyecto ha comenzado en la Reserva de la Biosfera de Tehuacán-Cuicatlán (rbtc), con el apoyo de actores como el Fondo Mexicano para la Conservación de la Naturaleza, A. C., la Comisión Nacional Forestal y el Servicio de Pesca y Vida Silvestre de Estados Unidos; la intención es que se impulse el interés de los poseedores legales de la tierra para realizar acciones de monitoreo participativo que sustenten proyectos de desarrollo sustentable a nivel local. Se presentan los nombres común y científico para cada especie incluida en esta guía de campo, y un árbol genealógico que indica su historia evolutiva y los parientes más cercanos. Adicionalmente, se consideran tres elementos que hacen especial esta guía. La primera, en orden de aparición para cada ficha, es una ilustración que sirve para identificar visualmente a cada especie, en la mayoría de los casos es una acuarela inédita de Alfredo Dugès, un naturalista del siglo xix que dedicó gran parte de su vida a la descripción y clasificación de animales y plantas de México. Esto agrega a la guía una relevante importancia histórica. El segundo elemento es la ilustración y datos de los rastros que nos indican la presencia de la especie en campo. Estas ilustraciones fueron realizadas por el experto en rastros de México, el M. en C. Marcelo Aranda. El rastreo es un método de monitoreo participativo muy importante y es fundamental poner atención en los rastros para mejorar los resultados obtenidos mediante fototrampeo. El tercer elemento es la imagen de una fotocolecta obtenida durante el trabajo de monitoreo en la rbtc. Esta publicación proporciona las características morfológicas, como el peso y tamaño de las especies, además de indicar mediante ilustraciones su distribución, ecología, patrones de actividad y comportamiento observados en la rbtc. Esperamos que esta guía contribuya con el trabajo que usted está realizando con el fin de conocer la biodiversidad de la zona en la que habita, o si aún no se ha integrado al desarrollo del monitoreo esperamos sinceramente que disfrute de su revisión y lectura y que impulse su curiosidad por integrarse a esta actividad.

Discovered in the beginning of the XXth century and intensively explored almost a century afterwards, ‘Castro da Columbeira’ still offers unpublished information on the Chalcolithic of the Portuguese Estremadura. Belonging to a group of local archaeological sites that benefited from the impulse of amateur archaeology, it is considered a central element in the heritage policy of the municipality of Bombarral. A project was drawn to turn the site into a museum and simultaneously protocols have allowed young researchers at the Department of Archaeology in the University of Algarve have been allowed access to archaeological materials. The prelimi-nary data concerning both the lithic assemblage and the faunal remains studies are presented.

(pp. 29-32)

Species assemblages often have a non-random nested organization, which in vertebrate scavenger (carrion-consuming) assemblages is thought to be driven by facilitation in competitive environments. However, not all scavenger species play the same role in maintaining assemblage structure, as some species are obligate scavengers (i.e., vultures) and others are facultative, scavenging opportunistically. We used a database with 177 vertebrate scavenger species from 53 assemblages in 22 countries across five continents to identify which functional traits of scavenger species are key to maintaining the scavenging network structure. We used network analyses to relate ten traits hypothesized to affect assemblage structure with the "role" of each species in the scavenging assemblage in which it appeared. We characterized the role of a species in terms of both the proportion of monitored carcasses on which that species scavenged, or scavenging breadth (i.e., the species "normalized degree"), and the role of that species in the nested structure of the assemblage (i.e., the species "paired nested degree"), therefore identifying possible facilitative interactions among species. We found that species with high olfactory acuity, social foragers, and obligate scavengers had the widest scavenging breadth. We also found that social foragers had a large paired nested degree in scavenger assemblages, probably because their presence is easier to detect by other species to signal carcass occurrence. Our study highlights differences in the functional roles of scavenger species and can be used to identify key species for targeted conservation to maintain the ecological function of scavenger assemblages.

Squamates (lizards and snakes) are highly successful modern vertebrates, with over 10 000 species. Squamates have a long history, dating back to at least 240 million years ago (Ma), and showing increasing species richness in the Late Cretaceous (84 Ma) and Early Palaeogene (66–55 Ma). We confirm that the major expansion of dietary functional morphology happened before these diversifications, in the mid-Cretaceous, 110–90 Ma. Until that time, squamates had relatively uniform tooth types, which then diversified substantially and ecomorphospace expanded to modern levels. This coincides with the Cretaceous Terrestrial Revolution, when angiosperms began to take over terrestrial ecosystems, providing new roles for plant-eating and pollinating insects, which were, in turn, new sources of food for herbivorous and insectivorous squamates. There was also an early Late Cretaceous (95–90 Ma) rise in jaw size disparity, driven by the diversification of marine squamates, particularly early mosasa...

Despite the essential role that vertebrate scavengers play in ecosystems, most studies have been conducted in Europe and North America, and there is a lack of information on vertebrate scavengers in vast regions of the world. Our aim was to describe the functioning and composition of the unknown vertebrate scavenger assemblage in the Gobi Desert, Mongolia, and determine how carcass size and habitat type affect species composition and carrion use. We monitored carcasses with camera traps and we also conducted observation points to survey the raptor community and identify the proportion of raptor species making use of the carcasses. We recorded eight vertebrate scavenger species (five birds and three mammals) by camera trap and seven raptors at observation points. Over half of the raptor species recorded at the observation points were also found feeding on carrion. The two most threatened species were only recorded in the mountain habitat. Furthermore, scavenger abundance and consumption rates were higher at large carcasses. This study highlights the importance of scavenging by raptors and other vertebrate scavengers for carrion elimination in ecosystems with extreme climatic conditions.

aBstraCt The etnoherpetological studies can contribute to knowledge about the diversity of amphibians and reptiles as well as the planning and development of strategies for the management, use and herpetofauna conservation in rural communities from a socioeconomic and cultural context. In the present study we analyzed and compared the general knowledge and cultural conception of residents of three communities near the city of Irapuato, resumen Los estudios etnoherpetológicos pueden contribuir al conocimiento sobre la diversidad de los anfibios y reptiles así como a la planeación y desarrollo de estrategias para su manejo, uso y conservación en comunidades rurales desde contexto socio-económico y cultural. En el presente estudio se analizó y comparó el conocimiento general y concepción cultural que tienen los habitantes de tres comunidades rurales aledañas a la ciudad de Irapuato, Guanajuato sobre su herpetofauna. En este estudio a partir de los resultados obtenidos en 180 encuestas se reco-nocieron 24 especies; ocho anfibios y 16 reptiles. Los habitantes de VAL (Valencianita) y COP (El Copal) presentaron similitud en relación a su conocimiento de las especies identificadas, más no así con CUCh (Cuchicuato). De las 24 especies, 12 se consideraron peligrosas por los habitantes de las tres comunidades: Una de sapo, dos de lagartijas y nueve de serpientes. Ranas, tortugas y la culebrita Indotyphlops braminus " lombriz " no se consideraron peli-grosas. Entre los usos y tradiciones destacan: a-medicinales, b-gastronómicos, c-como mascotas, y d-importancia cultural. Lo observado en este trabajo resalta la importancia del conocimiento tradicional con el que cuentan los pobladores de las tres comunidades sobre los anfibios y reptiles, siendo el grupo de las serpientes el que reflejo una mayor importancia cultural. Paralelamente este tipo de estudios pueden ser una referencia para conocer el estado de conservación de la herpetofauna local así como de la percepción cultural de las poblaciones humanas en relación a vertebrados como los anfibios y reptiles.

The non-avian saurischians that have associated eggshells and embryos are represented only by the sauropodomorph Massospondylus and Coelurosauria (derived theropods), thus missing the basal theropod representatives. We report a dinosaur clutch containing several crushed eggs and embryonic material ascribed to the megalosaurid theropod Torvosaurus .Itrepresents the first associated eggshells and embryos of megalosauroids, thus filling an important phylogenetic gap between two distantly related groups of saurischians. These fossils represent the only unequivocal basal theropod embryos found to date. The assemblage was found in early Tithonian fluvial overbank deposits of the Lourinhã Formation in West Portugal. The morphological, microstructural and chemical characterization results of the eggshell fragments indicate very mild diagenesis. Furthermore, these fossils allow unambiguous association of basal theropod osteology with a specific and unique new eggshell morphology.

The understanding of global diversity patterns has benefitted from a focus on functional traits and how they relate to variation in environmental conditions among assemblages. Distant communities in similar environments often share characteristics, and for tropical forest mammals, this functional trait convergence has been demonstrated at coarse scales (110-200 km resolution), but less is known about how these patterns manifest at fine scales, where local processes (e.g. habitat features and anthropogenic activities) and biotic interactions occur. Here, we used standardized camera trapping data and a novel analytical method that accounts for imperfect detection to assess how the functional composition of terrestrial mammal communities for two traits-trophic guild and body mass-varies across 16 protected areas in tropical forests and three continents, in relation to the extent of protected habitat and anthropogenic pressures. We found that despite their taxonomic differences, communities generally have a consistent trophic guild composition, and respond similarly to these factors. Insectivores were found to be sensitive to the size of protected habitat and surrounding human population density. Body mass distribution varied little among communities both in terms of central tendency and spread, and interestingly, community average body mass declined with proximity to human settlements. Results indicate predicted trait convergence among assemblages at the coarse scale reflects consistent functional composition among communities at the local scale, suggesting that broadly similar habitats and selective pressures shaped communities with similar trophic strategies and responses to drivers of change. These similarities provide a foundation for assessing assemblages under anthropogenic threats and sharing conservation measures.

The non-avian saurischians that have associated eggshells and embryos are represented only by the sauropodomorph Massospondylus and Coelurosauria (derived theropods), thus missing the basal theropod representatives. We report a dinosaur clutch containing several crushed eggs and embryonic material ascribed to the megalosaurid theropod Torvosaurus. It represents the first associated eggshells and embryos of megalosauroids, thus filling an important phylogenetic gap between two distantly related groups of saurischians. These fossils represent the only unequivocal basal theropod embryos found to date. The assemblage was found in early Tithonian fluvial overbank deposits of the Lourinhã Formation in West Portugal. The morphological, microstructural and chemical characterization results of the eggshell fragments indicate very mild diagenesis. Furthermore, these fossils allow unambiguous association of basal theropod osteology with a specific and unique new eggshell morphology.