Ancestros

Fil: Superina, Mariella. Laboratorio de Endocrinología de la Fauna Silvestre. Instituto de Medicina y Biología Experimental de Cuyo. Centro Científico Tecnológico. Mendoza; ArgentinaFil: Abba, Agustín Manuel. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Zaedyus pichiy (Cingulata: Dasypodidae)

Fil: Superina, Mariella. Instituto de Medicina y Biología Experimental de Cuyo. CCT. Mendoza; ArgentinaFil: Abba, Agustín Manuel. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Zaedyus pichiy (Cingulata: Dasypodidae)

Zaedyus pichiy (Desmarest, 1804) is a small armadillo commonly known as pichi. Like all armadillos, it bears a carapace of ossified dermal scutes covered by epidermal scales, but it is the only species that bears marginal scutes with sharply pointed apices. This diurnal, semifossorial species inhabits xeric shrublands and grasslands on sandy soils from central Argentina and Chile south to the Straits of Magellan. Z. pichiy has opportunistic omnivorous food habits and is the only xenarthran known to enter hibernation. It is listed as "Near Threatened" by the International Union for Conservation of Nature and Natural Resources; it is mainly threatened by humans who hunt it for food or sport.Facultad de Ciencias Naturales y Muse

El ornitorrinco

El ornitorrinco es un particular mamífero perteneciente al orden de los monotremas. En la actualidad este grupo está representado solo por cuatro especies (tres equidnas, géneros Tachyglossus y Zaglossus, y un ornitorrinco, Ornithorhynchus anatinus) presentes en Oceanía, aunque hace unos 63 millones de años el grupo estaba representado en América del Sur (Patagonia). Actualmente sólo se lo registra en Australia y Tasmania y se puede decir que es uno de los mamíferos más raros que existen, ya que pone huevos, tiene pico, es venenoso y puede electrolocalizar a sus presas.Serie Moradores del Museo | División Zoología VertebradosFacultad de Ciencias Naturales y Muse

El ornitorrinco

El ornitorrinco es un particular mamífero perteneciente al orden de los monotremas. En la actualidad este grupo está representado solo por cuatro especies (tres equidnas, géneros Tachyglossus y Zaglossus, y un ornitorrinco, Ornithorhynchus anatinus) presentes en Oceanía, aunque hace unos 63 millones de años el grupo estaba representado en América del Sur (Patagonia). Actualmente sólo se lo registra en Australia y Tasmania y se puede decir que es uno de los mamíferos más raros que existen, ya que pone huevos, tiene pico, es venenoso y puede electrolocalizar a sus presas.Serie Moradores del Museo | División Zoología VertebradosFacultad de Ciencias Naturales y Muse

El ornitorrinco

El ornitorrinco es un particular mamífero perteneciente al orden de los monotremas. En la actualidad este grupo está representado solo por cuatro especies (tres equidnas, géneros Tachyglossus y Zaglossus, y un ornitorrinco, Ornithorhynchus anatinus) presentes en Oceanía, aunque hace unos 63 millones de años el grupo estaba representado en América del Sur (Patagonia). Actualmente sólo se lo registra en Australia y Tasmania y se puede decir que es uno de los mamíferos más raros que existen, ya que pone huevos, tiene pico, es venenoso y puede electrolocalizar a sus presas.Serie Moradores del Museo | División Zoología VertebradosFacultad de Ciencias Naturales y Muse

Ecología y conservación de los armadillos [Mammalia, Dasypodidae] en el noreste de la provincia de Buenos Aires, Argentina

Tesis presentada para optar al Grado de Doctor en Ciencias NaturalesFil: Abba, Agustín Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

High proportion of cactus species threatened with extinction

A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31% of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands. The distribution of threatened species and the predominant threatening processes and drivers are different to those described for other taxa. The most significant threat processes comprise land conversion to agriculture and aquaculture, collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder livestock ranching and smallholder annual agriculture. Our findings demonstrate that global species assessments are readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation priorities and actions to those derived from species assessments of key animal groups.La lista completa de autores que integran el documento puede consultarse en el archivo.Facultad de Ciencias Naturales y Muse

Population ecology of <i>Chaetophractus vellerosus</i>: The first report for an armadillo in South America

The aim of this work was to obtain the first estimates of survival rates (S), capture probability (p) and life expectancy for armadillos in South America by analyzing capture-mark-recapture data obtained from a population of Chaetophractus vellerosus (Gray, 1865) located in Magdalena, Buenos Aires, Argentina. From June 2006 to June 2011, we conducted 16 field surveys that resulted in 365 capture events of 152 adult C. vellerosus. For the survival analysis we used a Cormack-Jolly-Seber (CJS) modelling framework. Interannual variation in S made an important contribution to overall variation in the survival rate of C. vellerosus. The average life expectancy for females and males after attaining sexual maturity was estimated at 1.70 and 1.65 years respectively. The period of lowest survival probability was associated with dry seasons that might have affected the availability of food. This study provides the first estimates of demographic parameters for xenarthrans in South America.Centro de Estudios Parasitológicos y de Vectore

Population ecology of <i>Chaetophractus vellerosus</i>: The first report for an armadillo in South America

The aim of this work was to obtain the first estimates of survival rates (S), capture probability (p) and life expectancy for armadillos in South America by analyzing capture-mark-recapture data obtained from a population of Chaetophractus vellerosus (Gray, 1865) located in Magdalena, Buenos Aires, Argentina. From June 2006 to June 2011, we conducted 16 field surveys that resulted in 365 capture events of 152 adult C. vellerosus. For the survival analysis we used a Cormack-Jolly-Seber (CJS) modelling framework. Interannual variation in S made an important contribution to overall variation in the survival rate of C. vellerosus. The average life expectancy for females and males after attaining sexual maturity was estimated at 1.70 and 1.65 years respectively. The period of lowest survival probability was associated with dry seasons that might have affected the availability of food. This study provides the first estimates of demographic parameters for xenarthrans in South America.Centro de Estudios Parasitológicos y de Vectore