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OBJECTIVES Across Europe there are significant variations in the fundamental structure and content of cardiothoracic surgery (CTS) training programmes. Previous efforts have been made to introduce a Unified European Training System, which outlined the fundamentals of the ideal programme and supported a paradigm shift from an apprenticeship to a competency-based model. This article’s goal was to define key structural, administrative and executive details of such a programme to lay the foundations for the standardization of cardiothoracic surgical training across Europe. METHODS The European Association for Cardiothoracic Surgery Residents Committee had previously conducted a residents’ training survey across Europe in 2020. Training curricula from the twelve most represented countries across Europe were either searched online or obtained from the countries’ national trainee representative and reviewed by the committee. Information was collated and placed into one of the following categories to develop the position paper: (i) selection of eligible candidates, (ii) guidance for an outcome-based syllabus, (iii) documentation and evaluation of training progress, (iv) mandatory rotations and training courses, (v) number of independent or assisted cases and (vi) requirements and quality assurance of teachers. RESULTS An independent professional body should promote an outcome-based syllabus and take responsibility for the training programme’s quality assurance. Trainees should be selected on merit by an open and transparent process. Training should be delivered within a defined period and supervised by an appointed training committee to ensure its implementation. This committee should review the trainees progression regularly, provide feedback and offer trainees the opportunity to experience various training environments and trainers. A common electronic portal be used by trainees to record their agreed objectives and to evidence their completion. Trainees should regularly attend specialty-relevant courses and conferences to promote professional and academic development. The end of training is reached when the formal requirements of the training programme are met and the trainee is able to perform at the level expected of a day-1 independent surgeon. CONCLUSIONS This article defines the key structural, administrative, and executive principles for CTS training. Programmes are encouraged to review and modify their training curricula, if necessary, to ensure the delivery of high-quality, standardized, outcome-orientated CTS training across Europe.

Understanding the genetic responses of different species to the landscape attributes is essential to improve conservation actions and decision-making. However, making generalizations about such responses is not trivial, since they can be influenced by several factors. Aspects related to landscape matrix quality, for example, such as contrast and heterogeneity, may play a relevant role in the spatial-genetic structuring of populations since functional connectivity is influenced by the degree of matrix permeability. Intending to identify trends of genetic responses to habitat fragmentation and the aspects influencing these responses, we employed a meta-analytical approach to investigate the degree of genetic structuring of small mammal populations, measured through the fixation index (FST), in anthropogenic landscapes. For this, we obtained data of 28 species from 38 studies worldwide. We investigated the heterogeneity among species’ responses by focusing on the influence of matrix quality (contrast and heterogeneity), and species’ life-history traits (mean dispersal distance, generation time, and locomotor mode), controlling the influence of the marker type used in the study and the isolation by distance (IBD) among the patches habitat. We found a consistent pattern of genetic structuring of small mammal populations in anthropogenic landscapes, which present a significant genetic differentiation. Genetic structure is mostly influenced by matrix quality characteristics so that populations established in landscapes with high contrast and more heterogeneous matrices tend to be more structured. Also, populations of species with long generation time and high dispersal capacity exhibit a greater degree of genetic structure. Besides, accounting for IBD as a fixed effect was crucial to understand the variation among studies’ findings. Thus, the degree of genetic structuring of small mammal populations reflects the functional connectivity of the landscape, resulting from a balance between landscape attributes (matrix contrast and heterogeneity) and species’ life-history traits. Overall, our findings suggest that small mammals may be more susceptible to fragmentation than previously recognized, calling for special attention to this group considering their importance to maintain community structure and ecosystem functioning.

We compare temporal variations in leaf fall among three sites of evergreen Atlantic Forest and analyze how climatic variables influence it. Sites were located at Serra dos Orgaos National Park at different altitudes. Litter was collected monthly, from September 1997 to September 2005. Leaves were separated from other litter elements, oven-dried and weighted. Differences in leaf fall mass among grids and how they correlated with temporal variations were analyzed. Climatic variables were obtained from a nearby station and deviations from climatological normals were analyzed. We grouped climatic variables using Principal Component Analyses (PCA) and the highest scores of the two main factors were selected to construct regression models for different time lags. Leaf fall represented 50.5-70 percent of the total litter fall and mean leaf fall differed significantly among grids. However, leaf fall seasonality in the three areas were correlated. Leaf fall increased at the end of dry periods, when temperature and precipitation started to increase. Climatic variables were classified into two groups: seasonal and anomaly. Models constructed with lag variation from 0 and 6 months show that leaf fall was best explained by an anomaly in the maximum mean temperature, with lag 0, and by precipitation, with a six-month lag. We conclude that plant species respond immediately to drastic deviations from climatic factors, while regular climatic conditions are responsible for the seasonality of leaf fall, most likely as a late response to water shortage at the end of the dry season. .

Tropical forest marsupials exhibit large interannual variation in population sizes, with direct negative density dependence capturing the essential features of their dynamics. However, the demographic mechanisms underlying population growth rate and driving both survival and reproduction are still unclear. We used a 16-year capture-mark-recapture data set for five tropical forest marsupials to test for seasonal and interannual density dependence in survival and recruitment. Hypotheses regarding the effects of exogenous (rainfall and minimum temperature) factors on survival, recruitment, and reproductive parameters (fecundity, litter size, and proportion of reproductive females) were also tested. Population size negatively affected survival in three of five species. High population sizes in a given year reduced survival rates in the following year, with strong detrimental effects on males. Recruitment and proportion of reproductive females were highly dependent on weather variables, and were not affected by previous population sizes (except for Metachirus nudicaudatus). Fecundity (number of female offspring/female) was related negatively to population size only in the black-eared opossum (Didelphis aurita), while litter size was a relatively conservative parameter, largely independent of external conditions. Our analyses indicate that density-dependent survival is the mechanism that regulates population size of tropical forest marsupials, either through a reduction in survival or an increase in emigration rates. This general regulatory mechanism may be common to other marsupials in the Atlantic Forest and other tropical forests. Marsupiais de florestas tropicais exibem grande variação interanual nos tamanhos populacionais, com dependência negativa e direta da densidade capturando a essência de sua dinâmica populacional. No entanto, os mecanismos demográficos subjacentes à taxa de crescimento populacional e determinantes da sobrevivência e reprodução ainda são incertos. Nós usamos 16 anos de dados de captura-marcação-recaptura de cinco espécies de marsupiais de florestas tropicais para avaliar a dependência de densidade sazonal e interanual na sobrevivência e recrutamento. Hipóteses sobre efeitos de fatores exógenos (pluviosidade e temperatura mínima) na sobrevivência, recrutamento e parâmetros reprodutivos (fecundidade, tamanho da ninhada e proporção de fêmeas reprodutivas) também foram testadas. O tamanho da população afetou negativamente a sobrevivência em três das cinco espécies. O tamanho populacional elevado em um ano reduziu as taxas de sobrevivência no ano seguinte, com efeitos mais negativos nos machos. Recrutamento e proporção de fêmeas reprodutivas foram dependentes das variáveis climáticas e não foram afetados pelos tamanhos populacionais anteriores (com exceção de Metachirus nudicaudatus). A fecundidade (número de filhotes fêmea/fêmea) foi relacionada negativamente ao tamanho da população do gambá-de-orelha-preta (Didelphis aurita), enquanto o tamanho da ninhada foi um parâmetro relativamente conservador e independente das condições externas. Nossas análises indicam que a sobrevivência dependente da densidade regula as populações de marsupiais em florestas tropicais, seja através da redução na sobrevivência ou no aumento da emigração. Esse mecanismo regulatório pode ser comum a outros marsupiais na Mata Atlântica e outras florestas tropicais.

A lista mais recente dos mamiferos que ocorrem no Parque Nacional da Serra dos Orgaos (PARNASO), com 79 registros, consta no seu segundo Plano de Manejo, publicado em 2008. O presente estudo teve como objetivo atualizar a lista de especies de mamiferos do PARNASO, inserindo novos registros de especies obtidos atraves de dados primarios e revisao bibliografica, considerando o periodo de 2002 a 2018. A revisao da lista do Plano de Manejo resultou em 75 registros validos. Destes, tres especies foram consideradas localmente extintas ( Panthera onca , Tayassu pecari e Tapirus terrestris ) e nao foram incluidas na presente lista. Desse modo, listamos aqui 100 especies com registros recentes no PARNASO, o que representa um acrescimo de 28 especies. As ordens com maior riqueza de especies foram Rodentia e Chiroptera, com 32 e 23 especies, respectivamente. Das especies registradas, quatro sao invasoras ( Callithrix jacchus , C. penicillata , Rattus norvegicus e R. rattus ), tres sao domesticas ( Bos taurus , Canis familiaris e Felis catus ), e 26 sao ameacadas de extincao. A analise da distribuicao espacial da riqueza de especies mostrou que apenas metade da area do parque possui ao menos um registro, e que os registros estao concentrados onde ha infraestrutura para a pesquisa. A presenca de especies domesticas e invasoras, bem como as extincoes locais detectadas, indicam a necessidade de acoes de manejo no interior do parque. Esse grande acrescimo de especies a lista evidencia o desenvolvimento da pesquisa com mamiferos nesta Unidade de Conservacao e a necessidade de compilacoes mais frequentes dos resultados devido aos varios projetos em curso. O PARNASO tem papel de destaque na conservacao de mamiferos ao ainda manter uma das maiores riquezas de especies do Estado do Rio de Janeiro, e grande importância para a pesquisa, abrigando uma ampla gama de estudos e projetos de longa duracao. MAMMALS OF THE SERRA DOS ORGAOS NATIONAL PARK: UPDATED LIST OF SPECIES AND IMPLICATIONS FOR CONSERVATION The most recent list of mammals of the Serra dos Orgaos National Park (PARNASO) with 79 records is from its second Management Plan published in 2008. The present study aimed to update the list of mammal species of PARNASO, adding new species records obtained from primary data and bibliographic review, in the period between 2002 and 2018. The review of the Management Plan’s species list resulted in 75 currently valid records. Three of these 75 species, were considered locally extinct ( Panthera onca , Tayassu pecari and Tapirus terrestris ) and were not included in the present list. Thus, we list 100 species with recent records in PARNASO, which represents an increase of 28 species. The orders with higher species richness were Rodentia and Chiroptera, with 32 and 23 species, respectively. Among the species recorded, four are invasive ( Callithrix jacchus , C. penicillata , Rattus norvegicus and R. rattus ), three are domestic ( Bos taurus , Canis familiaris and Felis catus ), and 26 are endangered to extinction. The analysis of the spatial distribution of species richness shows that only half of the park area had at least one record, and that records were concentrated where there is logistic infrastructure. The great addition of species in the list highlights the increased research in this protected area and the need for more frequent compilations of results due to ongoing projects. The presence of domestic animals and invasive species, as well as local extinctions detected, indicate the need for management actions within the park. PARNASO plays a prominent role in the conservation of species while still maintaining one of the greatest mammal species richness in the State of Rio de Janeiro, and hosting a wide range of studies and long-term projects.

Despite the well-established anatomy nomenclature for the marsupial skeleton, there are no names for the epipubic bone structures. Epipubic bones are paired bones articulating with the pubis and projecting cranially in the ventral body wall, present on the pelvic girdle of cynodonts, monotremes and marsupials. These bones were commonly thought to be related to pouch support in marsupials and more recently associated with locomotion. The parts of the epipubic bones have not been named and this has impeded proper morphological analysis. We analyzed the epipubic bones of 302 skeletons comprising American and Australian marsupials, as well as 27 monotreme skeletons, and dissected 10 marsupials for myological attachments analysis. We suggest the following nomenclature for the epipubic bone structures: crest for the cranial end, shaft for the body of the bone, lateral tubercle and the medial articular process. Some markings on the epipubic bone include the oblique line, pertaining to the attachment of external abdominal oblique muscle from the opposite side. The pyramidalis line is the suggested nomenclature for the pyramidalis muscle attachment and the inguinal ligament line for the inguinal ligament attachment. Regarding myology and attachments, based on dissections and review of the literature, the muscles pyramidalis, pectineus, external and internal abdominal oblique, transversus abdominis and rectus abdominis and the structures linea alba, linea semilunaris and the inguinal ligament are connected to the epipubic bone. As has been previously noted, anatomically, epipubic bones are so named due to their position (epi-above, pubic-pubis), and the same applies to structures such as the "epipubic process" or "epipubic cartilage" in amphibians and reptiles. While testing epipubic bone homology in vertebrates is beyond the scope of this work, we believe that using "epipubic bones" or epipubic cartilage/process as standardized terms for the structures found in the most cranial part of the superior ramus of the pubis would facilitate better anatomical communication. This should be valid for other similar terms, such as "epipubes" or "prepubis", that might occur in the literature in relation to this same physiographic position, and it should also be named as epipubic. We believe that this nomenclature will help in future morphologic studies.

The Atlantic Forest is a heterogeneous and complex vegetation mosaic caused by variety of climatic, geomorphological, and edaphic conditions. It has long been known that the Atlantic Forest has one of the most diversified biotas on the planet, presenting high levels of endemism. Here, we update the knowledge regarding terrestrial vertebrates occurring in the Atlantic Forest, focusing on endemic species and presenting its main spatial patterns of diversity. We also analyzed the main knowledge gaps associated with these species. We identified 2,645 species of Tetrapoda in the Atlantic Forest, being 719 species of amphibians, 517 species of reptiles, 1,025 species of birds, and 384 species of mammals. The uniqueness of its fauna is impressive even in a global scale, as 2.8% of the world’s Tetrapoda species occurs only in the Atlantic Forest. For reptiles, this percentage is 1.3%, while for both birds and mammals, it hovers around 1.9%, but for amphibians, it reaches an impressive 6.6%. Spatially, most groups exhibit their highest species richness at the core of the Atlantic Forest, and this pattern becomes more evident when only endemic species are considered. Even with all its impressive diversity, 157 new Tetrapoda species were described in the Atlantic Forest in the last decade, mostly from poorly sampled regions or environments. An increase of sampling effort on these regions might increase the number of species on this biome, which already is one of the most diverse in the world.

To compare 7-year survival and freedom from reoperation, as well as early clinical and hemodynamic outcomes, after surgical aortic valve replacement (SAVR) with mechanical or bioprosthetic valves in patients aged 50-70 years.single-center retrospective cohort study including adults aged 50-70 years who underwent SAVR in 2012 with a mechanical or bioprosthetic valve. Median follow-up was 7 years. Univariable analyses were performed using Kaplan-Meier curves and Log-Rank tests for survival and freedom from reoperation analyses. Multivariable time-to-event analyses were conducted using Cox Regression.Of a total of 193 patients, 76 (39.4%) received mechanical valves and 117 (60.6%) received bioprosthetic valves. A trend for better survival was found for mechanical prostheses when adjusting for EuroSCORE II (HR: 0.35; 95%CI: 0.12-1.02, p=0.054), but using a backward stepwise Cox regression prosthesis type was not retained by the model as an independent predictor of survival. Moreover, mechanical prostheses showed trends for higher freedom from reoperation (100% vs. 95.5%, Log-Rank, p=0.076), higher median EuroSCORE II (2.52% vs. 1.95%, p=0.06) and early mortality (7.9% vs. 2.6%, p=0.086). However, after adjusting for EuroSCORE II, there was no significant difference in early mortality (OR: 2.3, 95%CI: 0.5-10.5, p=0.272). Regarding hemodynamic performance at follow-up echocardiogram, there were no differences other than left ventricular mass regression, which was not as pronounced in the mechanical group (-12% vs. -21%, p=0.002).Mechanical and bioprosthetic aortic valves prostheses showed similar mid-term survival in the 50-70 age group. Further prospective and larger studies are needed to provide evidence-based recommendations on this topic.

Mercury (Hg) is a widespread and toxic contaminant with potential for long-range atmospheric transport. Previous work has shown that temperate and subtropical montane ecosystems have great potential for deposition of this element. However, little information exists regarding Hg dynamics in tropical mountains. In present study, we evaluated the influence of altitudinal distribution, size, trophic position, and degree of water dependence on Hg concentration in amphibians. For this purpose, we determined the mercury concentration in topsoil and amphibian samples collected at 32 points distributed between 327 and 2181 m above sea level in Serra dos Orgaos, a mountainous complex located in southeastern Brazil. We analyzed the concentration of mercury in whole body samples of 200 individuals of 30 amphibian species. Trophic position of the specimens was estimated by nitrogen stable isotope (δ15N) composition in muscle tissues. We observed a positive relationship between elevation and Hg concentration in topsoil samples from rainforest sites. However, in samples from nebular forest and campos de altitude (highland grasslands) sites, the concentration of Hg was considered lower than expected by the trend in rainforest points, indicating that the vegetation structure plays an important role in the deposition of atmospheric mercury. Mercury concentration in amphibians varies according to the functional characteristics of the species and the environment in which the individual is inserted. Elevation, trophic level and water dependence explained at least some degree of variation in Hg concentration in amphibian tissues. Thus, this community-level analysis suggests that mountainous areas in the tropical region, as recorded for temperate and subtropical mountains, act as regional convergence and deposition sites for atmospheric mercury.

Patch size and isolation are traditionally considered as main determinants of species richness in fragmented landscapes, grounded on Island Biogeography Theory (IBT). The Habitat Amount Hypothesis (HAH) is the more recent alternative: species richness could be predicted exclusively by the total amount of habitat surrounding sampling sites. However, tests may be biased towards HAH by the use of poor metrics of patch isolation, and because landscape variables are measured only within the scale of effect for habitat amount. Here we compare the HAH, IBT, and patch isolation as predictors of species richness of forest-dependent small mammals in an Atlantic Forest fragmented landscape using two measures of patch isolation: considering all (overall) or only the nearest three (restrict) forest remnants within the scale of effect for each variable. The model with habitat amount had more support than models with patch size and isolation (representing IBT), or patch size alone, but the model with overall patch isolation was equally plausible. Had we used only restricted patch isolation, we would have found support only for the HAH, disregarding patch isolation. The appropriate metric of patch isolation is critical for robust tests of the HAH, which should be considered in future studies to avoid biased results in favour of the HAH. Our results provide strong evidence for either HAH or overall patch isolation over IBT, and both may offer simplicity to decision-making.

The metacommunity concept helps to understand how local and regional processes regulate species distributions in landscapes. Metacommunity structure is often assumed as static, but may be rather dynamic, following temporal changes along environmental gradients. We present an empirical test of the temporal dynamics of metacommunity structure, using small mammals in an Atlantic Forest landscape as a model system. We analyzed incidence matrices using the Elements of Metacommunity Structure framework and evaluated whether local, landscape, and spatial factors structured the metacommunity during different climatic seasons (HS = humid; SHS = super-humid) and time periods (1 = 1999–2001; 2 = 2005–2009). We compared HS-1 and SHS-1 to evaluate if metacommunity structure varies between seasons, and HS-1 and HS-2 to evaluate if it varies between time periods. Metacommunity structure changed from Clementsian (HS-1) to random (SHS-1), but during HS-2 it was Clementsian again. This suggests that groups of species are responding similarly to the major gradient of variation during the HS only. Patch size structured the metacommunity during both humid periods, and local habitat structure only during HS-1. We suggest that during the SHS these gradients are lost due to increased matrix permeability to movement, which homogenizes local communities resulting in a random structure. Species habitat requirements and specializations determined metacommunity structure, but only during the HS. The Clementsian structure indicates that forest disturbances may result in the loss of whole groups of species during the HS. Alternating patterns of metacommunity structure may be associated to changes on matrix suitability between seasons.

Habitat loss and fragmentation are likely to affect individual condition as they usually alter the quality of habitat. However, responses of individuals of different species to these processes may be subtle and difficult to detect, despite that such responses may reveal interesting and diverse strategies of persistence of species in fragmented landscapes. Here, we used model selection to 1) compare the body condition (Scaled Mass Index) of 2 Neotropical marsupials (Didelphis aurita and Philander frenatus) from 6 continuous forest sites and 25 forest fragments, and 2) determine whether local habitat structure and landscape and temporal factors affect body condition in forest fragments. Body condition of both species was lower in forest fragments compared to continuous forest sites, but only in the super-humid season for D. aurita and in the humid season for P. frenatus. When only forest fragments were compared, body condition of D. aurita was higher in the humid season, in sites with fewer Cecropia trees and water courses, lower percent forest cover, and surrounded by a mixed matrix (plantation and cattle ranching), or located in small rural properties. Body condition of P. frenatus was slightly higher in the super-humid season, in sites surrounded by a mixed matrix, with fewer Cecropia trees and water courses, more lianas, and greater percent forest cover. Our results revealed negative effects of habitat loss and fragmentation on both species, but also different responses of each species to local extrinsic environmental factors. We suggest that body condition should not be used as a direct indicator of animal fitness or habitat quality. Nonetheless, body condition may still reveal subtle and previously undetected responses of species to habitat disturbance and fragmentation.

Space and diet are frequently considered the two most important dimensions of an organism niche, but in tropical forests, these two dimensions are associated, with fruits more accessible in the canopy and upper strata of the forest, and arthropods more abundant in the forest litter. This constitutes a genuine macroecological pattern, potentially common to all tropical forests. We tested the existence of this trade-off between frugivory-insectivory in the vertical strata, and if it results from feeding specializations, using didelphid marsupials as a model group. We compared nine species, representing different lineages, which differ in diet and use of the forest strata, using phylogenetically independent contrasts. We classified species according to their use of the vertical strata into four categories based on the literature (terrestrial-semiaquatic, terrestrial-understory, underestory-subcanopy-canopy, and canopy only). Diet was analyzed by the proportion of nutrients (carbohydrates, fibers, proteins and lipids) in a cafeteria food preference experiment: more frugivorous diets have higher carbohydrate and fiber content, whereas more carnivorous and insectivorous diets have higher protein and lipid content. Along the phylogeny, increases in use of the vertical strata were significantly associated with increases in carbohydrate and fiber contents, and reductions in lipid content. Levels of protein content also reduced with increasing use of the vertical strata, but this association was not significant. The macroecological pattern of increasing frugivory with use of the upper strata is supported by the results for didelphid marsupials, which also indicate specialization is a mechanism involved. The contribution of didelphid marsupials to the ecosystem process of frugivory and seed dispersal is performed by a subset of species, despite being broadly described as omnivorous. Future studies should evaluate this macroecological pattern in more specialized taxonomic groups that vary in the use of the vertical strata, and if specialization is the general mechanism involved.

We compared urine concentration capacity among three phylogenetically closed sigmodontine rodent species that occur in two distinct habitats: Necromys lasiurus (xeric), Akodon cursor and Akodon lindberghi (mesic). Water conservation ability was evaluated in 30 h-trials, with urine collected every 6 h. A control (I- water and food ad libitum) and a test (II- food and water deprivation) were conducted for each species. Body mass loss (BML), urine volume (UV), urine relative volume (UVr) and urine concentration (UC) were compared between experiments I and II for each species and among species. Changes in urine osmolality between experiments were modeled using exponential and sine functions. Circadian variation of urine concentration was obtained by sine functions fit to the experiments I. Best fit was achieved for sine functions with an accumulation term for experiments II, showing that even in stressful conditions the circadian variation is still present. Highest UC and lowest BML were obtained from Necromys lasiurus individuals, which achieved them at faster rates. The lowest UC with highest BML were obtained for A. cursor individuals at slower rates and values than A. lindberghi, which were intermediate. Necromys lasiurus is more adapted for xeric habitats achieving higher urine concentration in shorter time and faster rate than species of genus Akodon.

Beginning in November 2018, Brazilian legislation regulating access to genetic heritage and associated traditional knowledge will cause a bureaucratic collapse of Biodiversity research in Brazil. Law number 13.123/2015 and Decree 8772/2016 impose severe barriers to basic and applied research, and to international cooperation by introducing mandatory registry of research access to native organisms in Brazil. This legal framework was meant to improve governmental control over systems of biotechnology research using genetic material and associated chemical compounds, which are central points of the Nagoya Protocol (CBD 2011) and the Convention on Biological Diversity (CBD 1992, 2012). However, the requirements imposed by the mandatory registry of research in the new National System for Governance of Genetic Heritage and Associated Traditional Knowledge (SisGen), the system of Material Transfer Agreements (MTAs), and the need to record access to organismal data prior to publication of scientific results or exportation of specimens for scientific research are technically impracticable and not part of the Nagoya Protocol or CBD ..

The effects of Brazil's political crisis on science funding necessary for biodiversity conservation are likely to be global. Brazil is not only the world's most biodiverse nation, it is responsible for the greater part of the Amazon forest, which regulates the climate and provides rain to much of southern South America. Brazil was a world leader in satellite monitoring of land-use change, in-situ biodiversity monitoring, reduction in tropical-forest deforestation, protection of indigenous lands, and a model for other developing nations. Coordinated public responses will be necessary to prevent special-interest groups from using the political crisis to weaken science funding, environmental legislation and law enforcement. © 2018 Magnusson, Grelle, Marques, Rocha, Dias, Fontana, Bergallo, Overbeck, Vale, Tomas, Cerqueira, Collevatti, Pillar, Malabarba, Lins-e-Silva, Neckel-Oliveira, Martinelli, Akama, Rodrigues, Silveira, Scariot and Fernandes.

Climatic seasonality affects marsupial space use through changes in food, mate, and nest availability. These effects can be enhanced when population size has an additive effect in the dry season. We tested if daily home range area and intensity of habitat use of the marsupial Metachirus nudicaudatus is affected by population size, climatic (dry and wet), and reproductive (breeding and non-breeding) seasons, and if it differs between genders. Metachirus nudicaudatus space use was affected by climatic seasonality, with individuals exploring larger areas in the dry season, probably in search for food. No effect of population size or differences in space use between sexes was detected. Further studies should test experimentally the effect of food availability on marsupials space use to confirm or rebut this hypothesis.

A teoria de metacomunidades busca explicar como processos que atuam em distintas escalas espaciais interagem para determinar a distribuicao e ocorrencia das especies localmente. Essa teoria tem se desenvolvido rapidamente nos ultimos anos, sendo considerada uma das areas mais promissoras para o estudo de respostas a mudancas ecologicas globais. No presente trabalho, apresentamos uma revisao dos conceitos que fundamentam a teoria, e propomos uma padronizacao da terminologia em portugues para os modelos e para os elementos de estrutura de metacomunidades. Duas abordagens principais sao discutidas: a abordagem mecanistica (e seus modelos de efeitos de massa, alocacao de especies, dinâmica de manchas e neutro), e a de elementos de estrutura de metacomunidades (coerencia, substituicao de especies e sobreposicao de limites). ABSTRACT - METACOMMUNITY: AN INTRODUCTION TO TERMS AND CONCEPTS Metacommunity theory aims to explain how processes that operate in distinct spatial scales interact to determine the distribution and local occurrence of species. This theory has developed rapidly in recent years, and is regarded as a promising approach to the study of global ecological changes. In the present study, we review the concepts related to the theory and propose a standardization of Portuguese terminology to refer to the models and the elements of metacommunity structure. Two major approaches are discussed: the mechanistic (and its models of mass effects, species sorting, patch dynamics and neutral), and the approach of elements of metacommunity structure (coherence, turnover, and boundary clumpling).

The conditions that a population experiences during one season can affect the strength of density dependence in the following season. In the tropics, many populations face their biggest challenges in the dry season due to limited food and cold-dry conditions. Seasonal environmental changes can be especially problematic for small, short-lived, seasonally breeding endotherms. To investigate the effects of seasonality on population dynamics, we studied five marsupial species in the Brazilian Atlantic Forest, using a 16-year dataset. We tested if (1) compensatory density feedback is stronger in the dry season, due to the high population sizes and limited food; (2) lower temperatures and the overall abundance of small mammals negatively affect dry season population growth rates; and (3) rainfall, a proxy for food availability, is positively related to wet season population growth rates. Population growth rates were regressed against seasonal population sizes and exogenous variables, and analyzed with linear autoregressive models. Seasonal compensatory density feedback occurred in both seasons, with compensation processes in just one season being sufficient to allow population persistence. Rainfall and the overall abundance of small mammals had little influence on populations, while colder temperatures decreased population growth rate of smaller species in both seasons. Although the study marsupials share similar life histories and phylogeny, they varied with respect to the season when compensatory density feedback was strongest. Our results demonstrate that seasonality plays a key role in driving marsupial population dynamics, and highlight the need to account for seasonality in demographic studies even in tropical environments.

We studied phenotypic variation in water opossum Chironectes minimus through morphological variation in size and shape of 16 cranial characters among six groups of populations of Chironectes defined by a transect analysis named according their main distributions: Central America, Venezuela/Colombia, Guianas, Belem, Bolivia/Peru, and Atlantic Forest. We also studied environmental variation among the groups and the influence of temperature seasonality and minimum temperature of coldest month on the body size of C. minimus. Morphometric differences in both size and shape were sharp between two major groups: Atlantic Forest and Central America+Venezuela/Colombia+Belem. The same pattern of differentiation was also observed in the environmental variables each group experiences. We also found a negative relationship between body size and temperature seasonality which showed that C. minimus follows a converse Bergmann’s rule cline. Our results on morphometric and environmental space suggest that specimens from the Atlantic Forest are different from specimens from Central America+Venezuela/Colombia+Belem both in size and shape and environmentally. We suggest that these major groups may comprehend different clades but a proper taxonomic assessment is needed to confirm our hypothesis.

Background The role of bats as reservoirs of zoonotic agents, especially pathogenic bacteria such as Bartonella and Coxiella, has been discussed around the world. Recent studies have identified bats as potential hosts of species from the proteobacteria phylum. In Brazil, however, the role of bats in the natural cycle of these agents is poorly investigated and generally neglected. In order to analyze the participation of bats in the epidemiology of diseases caused by Bartonella, Coxiella, Rickettsia, Anaplasma and Ehrlichia, we conducted a descriptive epidemiological study in three biogeographic regions of the Brazilian Atlantic Forest. Results Tissues of 119 bats captured in preserved areas in the states of Rio de Janeiro, Bahia and Santa Catarina from 2014 to 2015 were submitted to molecular analysis using specific primers. Bartonella spp. was detected in 22 spleen samples (18.5%, 95% CI: 11.9–26.6), whose phylogenetic analysis revealed the generation of at least two independent clusters, suggesting that these may be new unique genotypes of Bartonella species. In addition, four samples (3.4%, 95% CI: 0.9–8.3) were positive for the htpAB gene of C. burnetii [spleen (2), liver (1) and heart (1)]. Rickettsia spp., Anaplasma and Ehrlichia were not identified. This is the first study reporting C. burnetii and Bartonella spp. infections in bats from the Atlantic Forest biome. Conclusions These findings shed light on potential host range for these bacteria, which are characterized as important zoonotic pathogens. Electronic supplementary material The online version of this article (10.1186/s12917-018-1603-0) contains supplementary material, which is available to authorized users.

Fragment size, isolation, and matrix properties have received considerable attention as predictors of species richness, abundance, and composition in habitat patches. However, measurements of habitat attributes or habitat quality are more directly related to the proximate effects of habitat fragmentation and may be more determinant of assemblages than traditional explanatory variables at local scales. We determine how habitat structure in fragments—a measure of habitat quality—compares to fragment size, isolation, and matrix properties as determinants of richness, abundance, and composition of non-volant small mammals in a fragmented landscape of Atlantic Forest. Small mammals were surveyed once in 25 fragments in the Macacu River watershed, Rio de Janeiro, Brazil, from 1999 to 2001 and 2005 to 2009. A total of 83 candidate models were formulated and compared by Akaike Information Criteria. Habitat structure was one of the main determinants of small mammal assemblages in fragments, as important as fragment isolation for species composition and climatic season for species richness. Rodents were more abundant in fragments with increased overstory and understory vegetation density and more fallen logs. The contrary pattern was found for overall species richness and for species of terrestrial habit, which were more abundant in fragments with more open forest: decreased overstory and understory vegetation density and less fallen logs. Habitat quality in fragments may be a more important determinant of assemblages of small mammals and other vertebrates than previously considered in landscape and land use studies. O tamanho e isolamento dos fragmentos e as propriedades da matriz têm recebido considerável atenção como preditores da riqueza, abundância e composição de espécies em manchas de habitat. Entretanto, medidas dos atributos do habitat ou da qualidade do habitat são mais diretamente relacionadas aos efeitos imediatos da fragmentação de habitat, e seriam mais determinantes das comunidades do que as variáveis explicativas tradicionais. Determinamos como a estrutura do habitat nos fragmentos—uma medida da qualidade do habitat—se compara ao tamanho e isolamento dos fragmentos, e às propriedades da matriz como determinantes da riqueza, abundância e composição de espécies de pequenos mamíferos não-voadores em uma paisagem fragmentada de Mata Atlântica. Os pequenos mamíferos foram amostrados uma vez em 25 fragmentos na Bacia do Rio Macacu, Rio de Janeiro, Brasil, de 1999 a 2001 e de 2005 a 2009. Um total de 83 modelos foram formulados e comparados utilizando o Critério de Informação de Akaike. A estrutura do habitat foi um dos principais determinantes das comunidades de pequenos mamíferos nos fragmentos de mata, tão importante quanto o isolamento entre fragmentos para a composição de espécies e os efeitos das estações climáticas sobre a riqueza de espécies. Os roedores foram mais abundantes nos fragmentos com estratificação vertical e sub-bosque mais densos e com maior presença de troncos caídos. O padrão contrário foi encontrado para a riqueza total de espécies e para espécies de hábito terrestre, que foram mais abundantes em fragmentos com estratificação vertical e sub-bosque menos densos e menor presença de troncos caídos. A qualidade do habitat em fragmentos pode ser determinante das comunidades de pequenos mamíferos e outros vertebrados, mais importante do que considerado previamente em estudos de paisagens e uso da terra.

Population fluctuations are the result of the combined action of endogenous (feedback structure) and exogenous factors (large- and local-scale climate variables). In this paper, we used a 13-year time series to identify the feedback structure in a population of the brown 4-eyed opossum Metachirus nudicaudatus and to test a hypothesis on the effects of El Niño Southern Oscillation and rainfall using Royama’s theoretical framework. Metachirus nudicaudatus was regulated by a strong 1st-order negative feedback, with intraspecific competition for food resources as the probable factor governing the endogenous system. Contrary to our expectations, El Niño did not explain the marsupial dynamics better than 1-year lagged rainfall, that may operate in 2 different manners: as a nonlinear perturbation effect influencing the strength of density dependence (intraspecific competition and intraguild predation) or as a lateral perturbation effect influencing the carrying capacity of the environment. As flutuações populacionais são resultado da ação conjunta de fatores endógenos (estrutura de retroalimentação) e exógenos (variáveis climáticas locais e de larga escala). A partir de uma série temporal de 13 anos, nós identificamos a estrutura de retroalimentação da população da cuíca marrom de quatro olhos Metachirus nudicaudatus , e testamos hipóteses a respeito dos efeitos do El Niño Oscilação Sul e chuva utilizando a abordagem teórica de Royama. Metachirus nudicaudatus é regulado por uma forte retroalimentação negativa de primeira ordem, com a competição intraespecífica por recursos alimentares como o provável fator que rege o sistema endógeno. Ao contrário do que esperávamos, o El Niño não explicou a dinâmica populacional deste marsupial melhor do que a chuva com a defasagem de 1 ano, que pode atuar em duas formas: como um efeito de perturbação não-linear, influenciando a força da dependência densidade (competição intraespecífica e predação intraguilda), ou como um efeito de perturbação lateral, influenciando a capacidade de suporte do ambiente.

Ongoing climate change and the human role as dominant cause behind it are undeniable and already affecting living systems around the globe. Nonetheless, the likely consequences of climate change to Neotropical biodiversity are still poorly understood. We used species distribution modeling to evaluate the likely effects of climate change to the seven species of wild cats that are endemic to the Neotropics. We gathered (and provide) 424 species occurrence records from museum collections and the literature. We run the analysis on the ModEco software, using four modeling algorithms and projected models into 2050 using data from International Panel on Climate Change's last Assessment Report, under a business-as-usual emission scenario (RCP 8.5), according to five Global Circulation Models. We used an ensemble-forecasting approach to reach a consensus scenario, including only models with AUC > 0.70 for the present climate dataset. We created ensembles using the majority rule. After this procedure, we ended with two final suitability models per species, one for the present and another for the future. Model performance varied among species and was related to species' climatic suitability area (the smaller the area, the greater the model performance), and species with the smaller ranges were predicted to lose the highest percentage of their current distribution under climate change. The projections under climate change points to important contraction of climatically suitable areas for all Neotropical felids except for L. geoffoyii . The remaining species show, in average, a 43.5% contraction of suitable areas, with L. jacobitus and L. guigna showing more than 50% contraction. Both are already threatened under IUCN and Leopardus jacobitus , found only in the higher elevations of the Andes, is of special concern because highland species are particularly susceptible to a warming climate.

We tested the water conservation ability of three species of the genus Trichomys that occur in localities with very different climatic regimes, T. fosteri (Pantanal -- seasonal wetlands), T. aff. laurentius (Cerrado - savanna) and T. laurentius (Caatinga -- shrub land). Individuals were submitted to laboratory urinary concentration experiments using two treatments: one where food and water ad libitum were offered (control experiment - I) and the other of food and water deprivation (test experiment - II). Experiments were conducted during 24 hours and urine volume was collected and measured every 6 hours. We compared the differences in body mass, body mass loss (BML), urine volume (UV), relative urine volume (UVr) and urine osmolality (UO) between treatments for each species and between species for the test experiment (II). The patterns of temporal variation in urine concentration were also analyzed during the experiments. T. fosteri has signifcantly higher body mass than the other species. Signifcant differences were found in UV, UVr and UO but not in BML when experiments I and II were compared. Interspecifc comparisons showed no differences between species, except for UV, which was correlated with body mass and was higher for T. fosteri. All species presented low mean urine concentration values (T. aff. laurentius = 1226.14A608.03 mOsmol/kg, T. laurentius= 1210.02A662.68 mOsmol/kg, T fosteri= 1301A541 mOsmol/kg) compared to other South American rodents. All species showed high intraspecifc variability. Some individuals of T. laurentius reached values of UO higher than 3000mOsmol/Kg. The temporal patterns of urine concentration from experiments I and II were very similar for all species. Changes in the pattern of urine concentration over time were not obser- ved when comparing experiments I and II. The Thrichomys species studied here seem not to have effcient mechanisms for urine concentration. However, based on the high individual variability and the lack of changes in the short-term temporal variation, this question has to be better analyzed.

Effects of density dependence on animal movements have received much attention in ecology, but it is still debated to what extent dispersal and movements in general are density dependent, and their potential contribution to population regulation processes. Here, we determine the occurrence and nature of density dependence in the movements of a Neotropical marsupial, the black-eared opossum Didelphis aurita Wied-Neuwied 1826. Using spool-and-line tracking devices, we estimated the tortuosity of fine-scale movements of 149 individuals by their fractal dimension D. We evaluated the relative importance of population size, reproductive or climatic seasons and reproductive maturity of individuals as determinants of movement tortuosity, using a model selection approach. Population size was the most important determinant of movement tortuosity, with season (climatic seasons for females, reproductive seasons for males) and reproductive maturity as secondary but also important variables. We detected a positive density-dependent effect on movement tortuosity, resulting in more intensive use of areas by individuals during periods of high population size. This positive association between movement tortuosity and population size is more likely to result from intraspecific competition, which forces individuals to explore their environment more intensively during high-density periods. Therefore, despite being density dependent, movements in D. aurita apparently do not contribute to population regulation mechanisms.

Local abundance results from the interaction between populational and environmental processes. The abundance of the species in a community is also one of the most basic descriptors of its structure. Despite its importance, information about species abundances is fragmentary, creating a knowledge gap about species abundances known as the Prestonian Shortfall. Here we present a comprehensive data set of small mammal abundance in the Atlantic Forest. Data were extracted from 114 published sources and from unpublished data collected by our research groups spanning from 1943 to 2017. The data set includes 1,902 records of at least 111 species in 155 localities, totaling 42,617 individuals represented. We selected studies that (1) were conducted in forested habitats of the Atlantic Forest, (2) had a minimum sampling effort of at least 500 trap-nights, and (3) contained species abundance data in detail. For each study, we recorded (1) latitude and longitude, (2) name of the locality, (3) employed sampling effort, (4) type of traps used, (5) study year, (6) country, and (7) species name with (8) its respective abundances. For every locality, we also obtained information regarding its (9) ecoregion, (10) predominant vegetation type, and (11) biogeographic subdivision. Whenever necessary, we also (12) updated the species names as new species were described and some genera suffered taxonomic revision since the publication. The localities are spread across the Atlantic Forest and most of the small mammal species known to occur in Atlantic Forest are present in the data set, making it representative of communities of the entire biome. This data set can be used to address various patterns in community ecology and geographical ecology, as the relation between local abundance and environmental suitability, hypothesis regarding local and regional factors on community structuring, species abundance distributions (SAD), functional and phylogenetic mechanisms on community assembling.

The IUCN Red List is a widely accepted system for classifying species’ risk of extinction, based on quantitative criteria. Although IUCN discourages the liberal use of the category “Data Deficient” (DD), most assessed groups have a large number of their species assigned to this category, especially in the Tropics. Therefore, DD species can introduce considerable uncertainty into estimates of proportions of threatened species, and research focused on elucidating the true status of those species should be a priority. Here we propose a simple method to gather information on geographic distribution and guide the search for new populations of rare, small-ranged, forest species, using the literature, online data, and standard GIS procedures. The method involves: (i) creating a geographic distribution model; (ii) selecting the environmentally suitable sites from that model; (iii) removing sites that have lost natural vegetation; and (iv) removing habitat networks that are too small and/or isolated, based on thresholds established from known occurrence records and the literature for ecologically similar species. As a case study, we use Lonchophylla peracchii, a recently described forest-dependent bat endemic to southeastern Brazil. We found that environmentally suitable sites for L. peracchii are already heavily deforested, confirming habitat loss as a major threat. Importantly, we identified five priority sites to search for the species outside of its currently known distribution. From that, we discuss its likely status based on IUCN's Criterion B2 (Extent of Occurrence). This method could be useful for other poorly known forest species, especially in the Tropics where most of these species are, and funding for research and fieldwork is scarcest. Currently there are 1910 terrestrial vertebrates in tropical forest worldwide classified as DD that could be evaluated using this method, provided that they have at least 5–10 occurrence records.

The relative effect of survival and reproductive rates to population growth rate is expected to be similar across species with similar life-histories. We employed a matrix population model and sensitivity and elasticity analysis to assess the absolute and relative importance of age-specific survival and fertility to population growth rate of Didelphis aurita (Didelphimorphia, Didelphidae) in a rural area of Rio de Janeiro, southeastern Brazil. The results were compared to expectations for mammals that mature early and have short generation time, such as D. aurita. Prospective analysis showed that changes in pouch young and juveniles survival would have large effects on population growth rate, relative to other vital rates, being the most critical time periods in the life cycle of D. aurita, whereas the effect of fertilities were always low. These findings do not fit to the observed pattern in mammals that mature early, where reproductive parameters have the largest relative influence on population growth rate. Although reproductive rates were characterized by a relatively small influence on population growth rate, they are still relevant because of their high variability and response to potential environmental disturbances. The first application of matrix population models to a neotropical rainforest marsupial provides information on marsupial demography and life-history strategy, increasing comprehension of this unknown group.

1 Universidade Federal do Rio de Janeiro (UFRJ), Instituto de Biologia, Departamento de Ecologia, Laboratorio de Vertebrados, Av. Brigadeiro Trompowski, s/n, Cidade Universitaria, Ilha do Fundao, Caixa Postal 68020, Rio de Janeiro, RJ, Brasil. CEP: 21941-599. 2 Universidade Estadual do Rio de Janeiro (UERJ), Instituto de Biologia, Programa de Pos-Graduacao em Ecologia e Evolucao, Av. Sao Francisco Xavier 524, Maracana, Rio de Janeiro, RJ, Brasil. CEP: 20550-013. 3 Universidade Federal do Rio de Janeiro (UFRJ), Instituto de Biologia, Programa de Pos-Graduacao em Ecologia, Av. Carlos Chagas Filho 373, Cidade Universitaria, Ilha do Fundao, Rio de Janeiro, RJ, Brasil. CEP: 21942-599. 4 Fundacao Oswaldo Cruz (FIOCRUZ), Instituto Oswaldo Cruz, Laboratorio de Biologia e Parasitologia de Mamiferos Silvestres Reservatorios, Av. Brasil 4365, Pavilhao Lauro Travassos, Manguinhos, Rio de Janeiro, RJ, Brasil. CEP: 21040-360.

Acute Aortic Syndrome (AAS) affecting the ascending aorta still represents a challenge to cardiologists and cardiothoracic surgeons, being associated with high mortality even with early surgery.To describe the immediate post-operative results and long-term survival after the surgical treatment of type A AAS. Secondary outcomes include hospital mortality, length of hospital stay and long-term mortality.Retrospective longitudinal study, including all patients who underwent ascending aorta replacement for surgical treatment of type A AAS, in a tertiary center, between January 2005 and December 2015. Preoperative, surgical and postoperative characteristics were evaluated. In addition to the descriptive analysis, the impact of some variables on long-term mortality, hospital mortality and length of hospital stay was evaluated.We included 78 patients, the most common type of AAS was aortic dissection (92,3%). 6 patients died at operation room and 12 in the immediate post-operative period, completing 23,1% of in-hospital mortality. Considering 60 survivors who were followed by a mean time of 5 years, maximum of 12, we registered a cumulative survival at 1, 3, 5, 10-years of 93,5%, 84,3%, 77% and 69,5%, respectively. Marfan Syndrome was found to be a risk factor of higher long term mortality (HR: 3,85, p=0,045).Our study confirms previous observations associating AAS type A with high rates of morbidity and mortality, despite significant advances in diagnostic and therapeutic techniques.Introdução: O Síndrome Aórtico Agudo (SAA) é frequentemente um desafio para cardiologistas e cirurgiões cardioto- rácicos já que mesmo com cirurgia atempada confere uma mortalidade elevada. Objetivos: Descrever os resultados clínicos no pós-operatório imediato e mortalidade a longo-prazo após abordagem cirúrgica do SAA tipo A. O objetivo secundário é identificar que fatores estão associados com a mortalidade hospitalar, internamento prolongado e mortalidade a longo prazo. Métodos: Estudo retrospetivo longitudinal incluindo todos os doentes submetidos a substituição da aorta ascendente para tratamento cirúrgico de SAA tipo A, num centro terciário, entre janeiro de 2005 e dezembro de 2015. Foram excluídos SAA de causa traumática. Avaliaram-se retrospetivamente as características pré-operatórias, cirúrgicas e pós-operatórias. Para além da análise descritiva, foi estimado o impacto de determinadas variáveis na mortalidade a longo prazo através da regres- são de Cox e relativamente aos resultados secundários através de regressão logística. Resultados: Foram incluídos 78 indivíduos cujo principal tipo de SAA foi a disseção da aorta (92,3%). Registaram-se 6 mortes intraoperatórias e 12 no pós-operatório imediato, sendo a mortalidade hospitalar de 23,1%. Dos 60 indivíduos sobreviventes, o tempo médio de seguimento foi de 5 anos, máximo de 12 anos, com sobrevida cumulativa aos 1, 3, 5 e 10 anos de 93,5%, 84,3%, 77% e 69,5%, respetivamente. O Síndrome de Marfan foi preditor de maior risco de mortalidade a longo prazo (HR: 3,85, p=0,045). Conclusões: O nosso estudo confirma observações prévias associando o SAA tipo A a altas taxas de morbi-mortalidade, apesar dos avanços significativos em termos diagnósticos e terapêuticos.

O presente trabalho compara a composição e estrutura de assembléias vegetais de fragmentos florestais, com diferentes características em relação ao tipo de propriedades rurais do entorno, tamanho e histórico de uso, com uma área localizada dentro de uma unidade de conservação (área controle), na bacia do rio Guapiaçu. Em cada fragmento foram delimitadas duas parcelas de 50 x 100m, na mesma orientação sudoeste, no interior das quais foram medidos os DAP (Diâmetro Acima do Peito) e altura de todos indivíduos com DAP ≥ 5 cm e identificados até o menor nível taxonômico possível. A densidade, área basal total, riqueza e diversidade foram calculados. As assembléias foram comparadas quanto aos seus valores diâmétricos e proporção de indivíduos em classes de diâmetro. Os parâmetros fitossociológicos foram calculados e as vinte espécies de maior cobertura foram selecionadas com vistas à comparação da composição específica e de suas caracteríticas sucessionais. Todas as assembleías estudadas apresentam alta riqueza e diversidade de espécies, sendo igualmente constatadas, em relação à área controle, diferenças significativas em pelo menos uma das caracteríticas analisadas. Todas apresentam uma menor proporção de indivíduos nas classes diâmetricas maiores e de espécies secundárias tardias que na área controle. No entanto, para algumas delas correspondem valores totais de diâmetro igual ou maiores que os da área controle por conta da maior proporção de indivíduos em classes diâmetricas intermediárias que parece contribuir mais para o aumento desses valores. De forma geral, há maior abundância de espécies pioneiras e secundárias iniciais nos fragmentos florestais, porém a proporção destas categorias sucessionais varia entre eles evidenciando diferenças dos estágios sucessionais em que se encontram. Estas diferenças poderiam estar relacionadas a certa variabilidade dos distúrbios identificados no entorno. Os resultados obtidos aqui sugerem que fragmentos de mata rodeados por pequenas propriedades encontram-se em estágios sucessionais mais inicias e sujeitos a distúrbios mais severos. This paper presents an analysis of the composition and structure of plant assemblages of forest fragments with different characteristics (in relation to the type of rural properties in the surrounding area, size and disturbance history) and an area located within a Conservation Unit (control area) in the Guapiaçu river basin. In each fragment, two plots of 50 x 100m were delimited to the South and West, the height and DBH of all trees with DBH ≥ 5 cm were measured, and the individuals were identified to the lowest possible taxonomic level. The density, basal area and diversity were calculated and the DAP values and proportion of individuals in the diameter classes were compared between the assemblages. The phytosociological parameters were also calculated and twenty species of higher coverage indices were selected to compare the species composition and their successional characteristics. All assemblages studied had high species richness and species diversity. However, when compared to the control, all of them had significant differences in at least one of analyzed characteristics. All had a lower proportion of individuals in the largest diameter class and late secondary species. However, these differences did not corresponded to differences in the comparisons of individual DAP values. Some assemblages had DAP values equal to or higher than the control area. In fact, within some fragments, the higher proportion of individuals in the intermediate diameter classes contributes more to the total basal area value. In general, there was a greater abundance of pioneer and early secondary species in the forest fragments, but the proportion of these successional groups varied between them, showing the subtle differences in the successional stages that these fragments are in. These differences could be related to some variability of the environmental disturbances identified. Based on the results, it was found that the forest fragments surrounded by small farms are in initial successional stages and have been subjected to severer disturbances.

Population projection models have received much attention in ecology and made important theoretical advances in the last 50 years. They represent vital tools for improving conservation strategies and management actions. Here we attempt to join some of theoretical advances made in the field of population projection modelling, briefly revise the history and present some applications derived from population matrix models in ecological and evolutionary studies.

The characterization of the different taxa of the highly diverse genus Monodelphis is poorly understood, as is the case of their distribution. Historically, taxonomic studies of Monodelphis have been restricted to a few or single species, whereas molecular approaches have been used for estimating phylogenetic relationships between species. We carried out phylogenetic analyses of 14 Monodelphis species, including Monodelphis domestica, based on cytochrome b mitochondrial DNA sequences. Forty-five complete (1149 bp) sequences of this gene were obtained from 39 specimens of M. domestica collected in 23 localities of the Brazilian Cerrado, Pantanal, and Caatinga morphoclimatic domains; one of Monodelphis umbristriata, two of Monodelphis americana, and two of Monodelphis dimidiata. A total of 72 haplotypes were analyzed, 48 only in M. domestica. Analyses were carried out in conjunction with 46 other sequences retrieved from GenBank, including M. domestica, Monodelphis brevicaudata, Monodelphis glirina, Monodelphis emiliae, Monodelphis peruviana, Monodelphis osgoodi, Monodelphis handleyi, Monodelphis kunsi, Monodelphis americana, Monodelphis dimidiata, Monodelphis iheringi, Monodelphis reigi, and Monodelphis adusta, with six other different didelphid species used as outgroups. Maximum likelihood and Bayesian inference were similar in depicting phylogenetic relationships of different Monodelphis taxa. Two clades of M. domestica were defined on the basis of these results. Genetic distance estimates ranged from 3.2% to 6.2% between these clades of M. domestica. Population analyses were carried out to infer the likely demographic scenarios and the relationship between M. domestica haplotypes. Median-joining and spatial analyses showed two populations related to different morphoclimatic domains (Cerrado/Pantanal and Caatinga). These results indicate a population structure in M. domestica and the possibility that this taxon might represent a species complex.

Climate, altitude and vegetation are usually considered as limiting factors in plant and animal distribution. Among vertebrates, climate and vegetation have consistently been considered as major determinants of geographical distributions. Here we analyzed the role of climate and the vegetation in limiting the geographical range of Atlantic Forest species of Drymophila Swainson, 1824 and assessed the performance of discriminant analysis to model the distribution of sympatric taxa. From each empirical point (locality) we recorded the values for nine climatic variables and the type of vegetation. The climatic data were obtained from a climate database elaborated by the Laboratório de Vertebrados and vegetation data from the ecoregions digital map of Latin America. The overlap of the climatic distribution map with the ecoregion map suggested that both factors are important in limiting the geographical range of Drymophila species. The discriminant approach, as applied here, was not satisfactory when compared with similar analysis carried out on parapatric species.

The didelphid marsupial, Didelphis aurita, is suggested as an intraguild predator and as key-species in small mammal assemblages of the Atlantic Forest of Brazil. The field experiments required to test this hypothesis are complex to implement, but the recent revival of regression methods offers a viable alternative. Here we use the dynamic and static regression methods to determine the importance of D. aurita as a competitor and intraguild predator. Capture-recapture data from two localities in the Rio de Janeiro State were used, Garrafao (municipality of Guapimirim), a coastal forest of the Serra do Mar, and Barra de Marica, a costal sand dune vegetation. Population and microhabitat variables were monitored from April 1997 to April 2003 in Garrafao, and from January 1986 to July 1990 in Barra de Marica. Microhabitat variables were related to Canopy, Plant, Litter and Rock covers, Obstruction from 0 to 1.5 m, and Number of logs. Exploitation competition was tested by the dynamic method, which models the effects of D. aurita on the per capita growth rate of a species. Interference by predation or competition was tested by the static method, where the abundance of D. aurita at trap stations was regressed against the abundance of other small mammals, after removal of any variation associated with micro- habitat factors. Exploitation competition was not detected, but the interference of D. aurita was pervasive, affecting all small mammals studied in the two localities.The clear avoidance of D. aurita by all small mammals tested in two localities of different physiognomies indicates that it functions as an intraguild predator, even if actual predation by D. aurita is an occasional event.

The remaining Atlantic Forest fragments are structurally isolated by a matrix of pastures, plantations, or urban areas, and most remnants are small (

Density and biomass may reveal different aspects of the dynamics of populations, but most studies have focused on density or relative abundance. Density and biomass also may behave differently in parts of the population composed of males and females because of differences in vagility and parental care between sexes. Herein, we explore seasonal and multiannual variation in density and biomass in a population of black-eared opossums (Didelphis aurita). Females and males were analyzed separately for associations with precipitation and litterfall, indicators of resource availability. Litterfall, density, and biomass were estimated from 1997 to 2003 on three 0.64-ha trapping grids in an area of Atlantic Forest in Rio de Janeiro, Brazil. Density of females exhibited a significant increase during the study. Density and biomass of males were more variable, without any significant positive trend or correlation with precipitation or litterfall. Seasonal and biannual patterns of precipitation were detected, followed by the density and biomass of females with time lags varying from 0 to 1, and from 9 to 12 months. The relative stability of biomass of females, and its association with precipitation and litterfall, suggests that resource availability combined with density-dependent responses regulated the local population of females. The local population of males may be more influenced by the stochasticity resulting from the higher vagility of males.

The reproduction, development and growth of Akodon lindberghi were studied in captivity. The colony was derived from animals captured in Simão Pereira, Minas Gerais state, which represents a new area of geographical distribution known for this species. Twelve males and twelve females were crossed, producing 144 young in 53 litters. Post-partum oestrus was observed and gestation length was estimated in 23 days. Litter size ranged from 1 to 4 with a mean of 2.72 (SD = 0.97, n = 53) and modal size of 3. Sexual dimorphism was neither present in body mass at birth nor at weaning. There was a significant negative correlation between litter size and mass at birth or weaning. Permanent emergence of adult external appearance occurred at 15 days. Puberty for males and females was 43 and 42 days, respectively, and the first fecundation event for two females was recorded at 47 and 54 days of age. The weight growth was described by fitting a Gompertz model. No significant difference was found in any parameter of growth curves for males and females. Measurements (head-body, tail, hind foot and internal and external ear lengths) obtained for adult individuals also did not reveal the presence of sexual dimorphism.

The data published on reproduction of the species of the genus Didelphis (Didelphimorphia, Didelphidae) were compiled and analysed to identify general patterns. The duration of the breeding season for the Didelphis species varied from 12 months near the Equator to 6 months at latitude 25°S and varied inversely with latitude and litter size. The mean litter size varied from 4.2 in Colombia to 9.4 in New York and was positively associated with latitude and negatively with the duration of breeding season. We propose that the higher investment in production at higher latitudes was compensated by increased mortality owing to the seasonal variation in food availability and environmental variables in theses latitudes.

Natural diets of Didelphidae species vary in the amounts of invertebrates, fruits and small vertebrates eaten. We investigated the digestive morphology of ten species of didelphid marsupials varying in food habits. The purpose was to describe and to compare the shape and relative size of the digestive tract portions among species studied and relate them to food habits. The form of the gastrointestinal tract in this family is simple, with a unilocular stomach, small intestine, large intestine and caecum. Caluromys philander was the species with highest association between digestive tract measurements and its frugivorous habits. However, although its caecum is morphologically distinct from the other species, the relative length is small when compared to the more faunivorous Metachirus nudicaudatus. Stomach length of Philander frenata is related to a more carnivorous diet, while large intestine length of Didelphis aurita is related to its omnivore diet. The digestive tract measurements of the other species appear to be related with a variable degree of morphological differentiation from a generalized form related to omnivory toward a more carnivorous diet. Great caecum relative size distinguished Metachirus nudicaudatus from the most other species and its relationship with diet is not well understood.

We analyzed phenotypic variation in white-eared Didelphis and its relevance to the current taxonomy of these opossums. On the basis of morphologic and morphometric data we show that the white-eared Didelphis can be split into 3 groups of populations referred to as albiventris, pernigra, and imperfecta. Morphologically, pernigra possesses a large, peg-like 3rd upper premolar (P3), whereas albiventris and imperfecta possess a small, non-peg-like P3. Also, albiventris has 88% of its specimens in the gray dorsal color phase, whereas the other 2 groups show similar percentages of specimens in the gray and black color phases. Morphometrically, pernigra is significantly larger (P < 0.05; analysis of variance) than the other 2 groups in most traits. Squared Mahalanobis distances among the 3 groups were found to be high, and discriminant analysis was successful in separating groups (99% of cases correctly classified). The congruence in variation of independent traits indicates genetic differentiation among populations. In addition, the sharp discontinuity observed between the parapatric albiventris and pernigra in Bolivia suggests that limited or no gene flow occurs between them. We conclude that the 3 groups analyzed here merit taxonomic recognition at the species level.

Phenotypic evolutionary rates are reported for cranial characters of eight species of large-bodied Neotropical marsupials: Didelphis aurita, D. marsupialis, D. albiventris, Philander opossum, P. frenata, Lutreolina crassicaudata, Chironectes minimus, and Metachirus nudicaudatus. These rates were found to be lower than expected if cranial diversification in these opossums had occurred by mutation and genetic drift only, and it is clear that a greater diversification was prevented. As all parameters used in estimating rates were very conservative, the conclusion that stabilizing selection has predominated during the evolution of the skull of large-bodied opossums is fairly robust. We also show that directional selection sustained for 150 generations (158 years) or less is capable of producing differences of the same magnitudes as those found between various pairs of species. Therefore, we conclude that even where a particular differentiation has been caused by directional selection, neutral rate tests are unlikely to infer it. This is because following a morphological shift, stabilizing selection will progressively erase evidences of directional selection.

Schistosomiasis is a health problem in Brazil and the role of rodents in maintaining the schistosome life-cycle requires further clarification. The influence of Schistosoma mansoni on a population of Nectomys squamipes was studied by capture-recapture (1st phase, from June 1991 to November 1995) and removal (2nd phase, from April 1997 to March 1999) studies at Sumidouro, Rio de Janeiro, Brazil. During both phases coproscopic examinations were performed. At the 2nd phase the rodents were perfused and worms were counted. The population dynamics of parasites was studied. During the 1st phase, female reproductive parameters, longevity, recruitment and survivorship rates and migration patterns were studied in relation to schistosome prevalence. Water contamination (source of miracidia), abundance intermediate host and rodent migration were related to prevalence. The N. squamipes population was not obviously influenced by the infection, as shown by the high number of reproductive infected females, high longevity of infected individuals and the absence of a relationship between recruitment or survivorship rates and the intensity of schistosome infection. The data indicate that N. squamipes can increase transmission of S. mansoni in endemic areas and carry it to non-infected areas. Furthermore, this rodent can be used as an indicator of a transmission focus.

A five-year mark-recapture study of small mammals was conducted with sampling every two months in a rural area of Sumidouro, State of Rio de Janeiro, Brazil, from June 1991 to July 1996. Population sizes were estimated through MNKA estimator, survivorship and recruitment rates through Jolly-Seber estimator. Nectomys squamipes and Didelphis aurita were the most abundant species, followed by Akodon cursor, Philander frenata and Oligoryzomys nigripes. Marsupials reproduced from July/August to March, with the highest population sizes and recruitment rates in the end of the rainy periods and beginning of the dry period. Rodents were able to reproduce throughout the year. N. squamipes' population size was correlated with survivorship; peaks and the bulk of reproduction occurred during and after the rainy periods. A. cursor's population size increased in dry periods. These species displayed seasonal patterns of population dynamics related to reproduction, with some variations among years chiefly for the rodents.