Noé U. De La Sancha

DePaul University · Department of Environmental Science and Studies

Aim Deforestation of the Atlantic Forest of eastern Paraguay has been recent but extensive, resulting in a fragmented landscape highly influenced by forest edges. We examined edge effects on multiple dimensions of small mammalian diversity. Location Forest fragments of eastern Paraguayan Atlantic Forest. Methods We trapped small mammal species at...

Aim Mountains cover approximately 22% of the planet's terrestrial surface and have dramatic effects on climate and biodiversity. The rain shadow effect is a common feature on mountain ranges worldwide and its effects on ecology and evolution of species, particularly morphology, are incompletely known. Our aim is to identify the correlates that best...

Context The Dry Chaco spans more than 87 million hectares across Argentina, Bolivia, and Paraguay. This unique forest system has experienced extensive loss and fragmentation due to land-use change, with different land-use histories in the three countries. This forest loss has altered landscape connectivity for the Dry Chaco’s associated biota. Obj...

Species that live in degraded habitats often show signs of physiological stress. Glucocorticoid hormones (e.g., corticosterone and cortisol) are often assessed as a proxy of the extent of physiological stress an animal has experienced. Our goal was to quantify glucocorticoids in free-ranging small mammals in fragments of Interior Atlantic Forest. W...

The Atlantic Forest is the second most diverse forest system in South America, and only a fraction of its original distribution remains. In this study, we aim to use robust datasets of small mammals along the entire forest system to disentangle the main drivers for diversity along this gradient. More specifically, we aim to disentangle whether defo...

Given the current era of rapid biodiversity loss, there is an urgent need to understand the mechanisms driving the biodiversity dynamics in biodiversity hotspots because these results could guide make conservation actions to protect species under threat from rapid environmental changes and extensive human impacts. To achieve this goal, we have orga...

Understanding variation of traits within and among species through time and across space is central to many questions in biology. Many resources assemble species-level trait data, but the data and metadata underlying those trait measurements are often not reported. Here, we introduce FuTRES (Functional Trait Resource for Environmental Studies; pron...

The oryzomyine rodent Euryzoryzomys russatus is endemic to the Atlantic Forest of South America, where it inhabits mostly pristine humid forests. Previous phylogeographical studies performed with limited sample sizes indicated that rivers and climatic oscillations might have driven the diversification of this species. Here, we used a more comprehen...

The Atlantic Forest of eastern Paraguay has experienced extensive recent deforestation. Less than one-third of the region is forested, and the remaining forest largely consists of isolated remnants with potentially disrupted connectivity for forest fauna. We used a graph theory approach to identify those forest remnants that are important in mainta...

Background: The speckled-pelage brush-furred rats (Lophuromys flavopunctatus group) have been difficult to define given conflicting genetic, morphological, and distributional records that combine to obscure meaningful accounts of its taxonomic diversity and evolution. In this study, we inferred the systematics, phylogeography, and evolutionary hist...

Synopsis We argue that the current environmental changes stressing the Earth’s biological systems urgently require study from an integrated perspective to reveal unexpected, cross-scale interactions, particularly between microbes and macroscale phenomena. Such interactions are the basis of a mechanistic understanding of the important connections be...

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 Neotropica...

The mammals of Paraguay are still poorly known. We report a new genus for the country, Abrawayaomys, a spiny cricetid rodent endemic for the Interior Atlantic Forest. This record extends the distribution of the genus approximately 100 km, and west of the Paraná River. This addition increases the number of mammals in Paraguay to 184 and verifies tha...

Loss of habitat, specifically deforestation, is a major driver of biodiversity loss. Species-area relationship (SAR) models traditionally have been used for estimating species richness, species loss as a function of habitat loss, and extrapolation of richness for given areas. Sampling species relationships (SSRs) are interrelated yet separate drive...

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...

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...

Analyses of the dimensions and morphology of spermatozoa can be useful in the identification of mammalian species. We compared and contrasted sperm morphology and dimensions in 9 genera and 18 species of the family Cricetidae. Spermatozoa were obtained from the cauda epididymes of animals previously fixed in 10% formalin, and stained with Giemsa or...

Se evaluaron 179 especies, teniendo al tapiti Sylvilagus brasiliensis y al Dasypus septemcinctus como especies no evaluadas NE (ver capítulo Xenarthra). Entre las especies evaluadas, se resalta que 29 especies fueron catalogadas como Datos Insuficientes o DD, esto significa que la información disponible sobre estas especies en nuestro país es tan e...

Here we compile a data set comprising morphological and life history information of 279 mammal species from 39,850 individuals of 388 populations ranging from 5.83 to 29.75 decimal degrees of latitude and 34.82 to 56.73 decimal degrees of lon- gitude in the Atlantic forest of South America. We present trait information from 16,840 individ- uals of...

Measures of traits are the basis of functional biological diversity. Numerous works consider mean species-level measures of traits while ignoring individual variance within species. However, there is a large amount of variation within species and it is increasingly apparent that it is important to consider trait variation not only between species,...

Este libro contiene información sobre la categorización de especies de mamíferos del Paraguay. Introduce a los antecedentes de este tipo de categorización de especies silvestres de nuestro país y explica la metodología utilizada para la misma (UICN versión 3.1). Se describe para las especies amenazadas su situación actual, las amenazas que enfrenta...

Cranial ontogenetic analyses improve our understanding of function from developmental, ecological, and evolutionary perspectives. Akodon montensis is an abundant, omnivorous forest species that occupies many habitat types. We used traditional and geometric morphometric approaches to describe ontogenetic variation in skulls of A. montensis. We teste...

As the center of convergence of some of the major bioregions of South America, Paraguay is a biodiverse country of biogeographic importance. Yet despite a long history of natural history research, basic knowledge of its fauna, including mammals, is still lacking. The last updated list of Paraguayan mammals was published in 2002, but increased resea...

Even though Paraguay has had a long history of Mammalogy, since 2007, several new rodent, bat, marsupial, and armadillo species have been added to the list of known species for the country. Herein, we add two new species of marsupials to the fauna of Paraguay, Philander opossum and Cryptonanus unduaviensis. These records improve the understanding o...

Paraguay is a small landlocked country whose mammalian fauna is among the least studied in South America, as well as their parasites. As a result of a study of the effects of habitat fragmentation on small mammal biodiversity in eastern Paraguay, we have collected some parasites of cricetid rodents. Herein, we describe a new species of Litomosoides...

Aim To determine whether there is evidence of changes in small mammals distributions and emergent metacommunity structure in the Atlantic Forest resulting from extensive habitat loss and fragmentation associated with anthropogenic activities. Location South American Atlantic Forest from northeastern Brazil to eastern Paraguay. Methods Using presenc...

Se documenta de manera resumida la historia de la mastozoología paraguaya desde sus inicios, con los misioneros jesuitas del siglo XVI, hasta la actualidad. En los últimos 20 años ha habido una explosión en el número de trabajos publicados y personas interesadas en la mastozoología paraguaya, lo cual ha incrementado el número de especies conocidas...

Technological advances and increasing availability of high-resolution satellite imagery offer the potential for more accurate land cover classifications and pattern analyses, which could greatly improve the detection and quantification of land cover change for conservation. Such remotely-sensed products, however, are often expensive and difficult t...

The deforestation of eastern Paraguay is a relatively recent phenomenon, starting as early as the 1940s. Assuming that larger forest fragments retain mechanisms and patterns of biodiversity resembling the original forests, understanding these patterns is valuable for comparative, management, and conservation purposes. In this study, I document dive...

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The subgenus Marmosa (Micoureus) Lesson, 1842 includes six species of long-tailed, black masked mouse-opossums widely distributed in forested areas of the Neotropics from northern Argentina to Belize. Most of the nominal forms of Marmosa (Micoureus) have not been revised since 1933 and some currently accepted synonymies are in need of revision; sim...

Until now, there has been a single Paraguayan record of climbing rats of the genus Rhipidomys (Tschudi, 1845), and the specimen has not been identified at the species level. Remarkably, this record has been overlooked in recent mam-mal lists. Field work conducted in Paraguay during and since 2006 has produced the second and third records of Rhipi-d...

Proceratophrys avelinoi was only known from one reserve in Paraguay, located in the southern region of thecountry, in the Itapúa department. Herein we report the third record for the country which would be the first record forthe department of Alto Parana department extending the distribution of this species in the country over 200 km; we alsoprese...

Although Paraguay is a country with a long history of mammalogy (de Azara 1801, 1802, Rengger 1830; see historical accounts in Hershkovitz 1987 and Myers et al. 2002), its mammal fauna is one of the least known in South America (Pine 1982, Myers et al. 2002). This asser-tion is corroborated by the recent discovery in the coun-try of several new mam...

In the United States, Bayou virus (BAYV) ranks second only to Sin Nombre virus (SNV) in terms of hantavirus pulmonary syndrome (HPS) incidents, having been confirmed in cases from Texas and Louisiana since its discovery in 1994. This study on BAYV infection among sympatric, non-oryzomyine rodents ("spillover") in Freeport, TX, is the first to link...

Phylogenetic analysis of a fragment of the mitochondrial genome and qualitative and quantitative assessments of morphological variation suggest that, in its current conception, Thylamys pusillus (Desmarest, 1804) is a complex of at least three species. In the taxonomic arrangement proposed in this work, the populations in the Argentinean provinces...

Home range size and habitat use of seropositive Oryzomys palustris, primary host for the Bayou strain of hantavirus, were compared to that of seronegative individuals from March 2002 - August 2003 in a longitudinal field population study. There were significant macrohabitat associations with serological status, but selection for most microhabitat v...

Recent field work in Paraguay has increased our knowledge of its mammal fauna, especially in terms of its distribution. Herein, we report three specimens of Monodelphis kunsi (Didelphidae), which are the first for the country and represent a significant range extension for this species. Two of the specimens come from a natural mixture of Cerrado an...

What is currently known about the ecology of North American hantaviruses has come largely from studies on Sin Nombre virus (SNV). We conducted a longitudinal study of Bayou virus (BAYV), the second-leading agent of hantavirus pulmonary syndrome in the United States. Antibodies to hantavirus were detected from Oryzomys palustris (most commonly infec...

This paper compares the implementation strategies of five major biological corridor networks in North and Central America using six criteria based on their believed contribution to the long-term sustainable success of the corridors. The criteria used for comparison are biological, educational, economic, treatment of indigenous people, political, an...

An indirect kinetics-based spectrophotometric method is developed for the simultaneous quantitative determination of permanganate and dichromate ion concentrations in an unknown. The method is based upon differences in reaction times between pyrogallol red and the two analytes. Oxidation of pyrogallol red (PGR) by permanganate ion is rapid, whereas...

Experimental solubilities are reported for anthracene dissolved in ten binary mixtures containing 3-methoxy-1-butanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-methyl-1-butanol, 4-methyl-2-pentanol, 1-octanol, and 2-ethyl-1-hexanol at 25 C. Results of these measurements are used to test two mathematical representa...

Experimental solubilities are reported for pyrene dissolved in five binary alcohol + cyclohexanol and seven binary alcohol + 1-pentanol solvent mixtures at 26 °C. Alcohol cosolvents include 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, and 2-pentanol. Results of these measurements are used to test two mathem...