847 resultados para Preferred-habitat
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Bothrops pubescens is a member of the neuwiedi complex that occurs in southern Brazil and Uruguay. We studied the ecology of B. pubescens from a field site (at Santa Maria, Rio Grande do Sul, Brasil) and based on preserved specimens from the state of Rio Grande do Sul, Brasil. In Santa Maria, individuals were collected during visual encounter surveys (VES), in pitfall traps with drift fences and during incidental encounters. Most snakes found in the field were on the ground, mainly on leaf litter, in mosaics of light and shadow or in completely shaded areas. In disturbed areas, snakes were usually associated with country houses and agricultural fields. Snakes were found much more frequently in forests and forest edges than in open habitats. The diet of B. pubescens comprised small mammals (56.2% of individual prey found), anurans (21.2%), lizards (7.5%), snakes (7.5%), birds (5.0%), and centipedes (2.5%). Prey predator mass ratios ranged from 0.002-0.627, and larger snakes tended to consume larger prey. Bothrops pubescens seems to be able to survive in disturbed areas, mainly those close to forests, and this ability may be facilitated by its generalized feeding habits. Copyright 2005 Society for the Study of Amphibians and Reptiles.
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Sordellina punctata occurs throughout south and southeastern Brazil in the Atlantic Forest domain (states of São Paulo, Paraná and Santa Catarina). Records from the states of Rio de Janeiro and Mato Grosso do Sul are questionable. A new record from southwestern São Paulo extends its distribution west and northward, probably indicating a wider range in the past. Habitat use in S. punctata implies that it may be more associated with wetlands and other saturated areas than truly aquatics ones.
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The aim of this study was to investigate the students' preferred teaching techniques, such as traditional blackboard, power-point, or slide-projection, for biochemistry discipline in biomedicine and medicine courses from São Paulo State University, UNESP, Botucatu, São Paulo, Brazil. Preferences for specific topic and teaching techniques were determined from questionnaires on a Liquert scale from 1 to 5 (strongly disagree; disagree; neither agree, nor disagree; agree; strongly agree) distributed at the end of biochemistry discipline to 180 biomedical students (30 students/year) and 540 medical students (90 students/year), during the years 2000-2005. Despite of the different number of hours applied to the course topics for the two groups of students, the majority of undergraduates from biomedicine and medicine preferred metabolic topics. Although the perception of a medical student is expected to be different than that of a biomedical student, as the aims of the two programs are different, 92.4% of students from each course agreed or strongly agreed with the biochemistry topics, and 92.1% thought highly on this subject. The majority of students, a number of 139 undergraduates from biomedicine and 419 from medicine course, preferred traditional blackboard teaching than slide-projection, or power-point class. In conclusion, it is imperative that the health courses reflect on sophisticated technology and data presentation with high density of information in biochemistry discipline. The traditional classes with blackboard presentation were most favored by students from biomedicine and medicine courses. The use of students' preferred teaching techniques might turn biochemistry more easily understood for biomedical and medical students. © 2007 by The International Union of Biochemistry and Molecular Biology.
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Habitat heterogeneity and use of physical and acoustic space in anuran communities in Southeastern Brazil. We intended to verify if structural and physiognomical characteristics of water bodies influence on the degree of overlap among calling sites of 23 anurans species, if anuran species use different calling sites in different water bodies, and if there is some relationship between the degree of advertisement call (based on seven call features) and calling site differentiation. Then, we determined calling sites (based in four variables) and recorded the advertisement call for anuran species that occurred in 10 water bodies of northwestern São Paulo State. We also determined the environmental heterogeneity (based in four environmental descriptors) for each water body. Males of most species used similar calling sites in each water body, probably because of the high uniformity of the environment, as a consequence of agricultural impacts on edge vegetation of the studied ponds. Most species (18 out of 19 species) called from different sites in the ponds where they occurred, which can be associated with differences in horizontal and vertical distribution of vegetation in the studied ponds. From the 19 species analyzed, only males of Pseudopaludicola aff. saltica called in sites with the same characteristics in different ponds. Advertisement call of Hylidae species was more similar to each other than were Leiuperidae and Leptodactylidae among themselves. The aquatic/terrestrial anurans (Bufonidae, Leiuperidae, Leptodactylidae and Microhylidae) occupied similar calling sites but presented quite distinct advertisement calls, while Hylidae species presented an inverse pattern: a high similarity on advertisement call features but used different calling sites, which indicates a niche complementarity between physical (calling site use) and acoustic (advertisement call) space use. © 2008 Departamento de Ciências Biológicas.
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Includes bibliography
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In addition to feeding on carrion tissues and fluids, social wasps can also prey on immature and adult carrion flies, thereby reducing their populations and retarding the decomposition process of carcasses. In this study, we report on the occurrence and behavior of social wasps attracted to vertebrate carrion. The collections were made monthly from September 2006 to October 2007 in three environments (rural, urban, and forest) in six municipalities of southeast Brazil, using baited bottle traps. We collected Agelaia pallipes (Olivier, 1791) (n = 143), Agelaia vicina (Saussure, 1854) (n = 106), Agelaia multipicta (Haliday, 1836) (n = 18), and Polybia paulista Ihering, 1896 (n = 3). The wasps were observed feeding directly on the baits and preying on adult insects collected in the traps. Bait and habitat associations, temporal variability of social wasps, and possible forensic implications of their actions are discussed. © 2011 Entomological Society of America.
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Context The bush dog (Speothos venaticus) is difficult to observe, capture, and study. To date, indirect evidence and opportunistic field observations have been the primary sources of information about the species' ecology. Field data are urgently needed to clarify the species' ecological requirements, behaviour and movement patterns. Aims The present study uses 13 months of telemetry data from a group of bush dogs to begin to address questions about area requirements, habitat preferences and movement patterns of this difficult-to-study species. Methods We tracked a group of bush dogs (two adults, one juvenile, four young) in an area of intact and altered Cerrado (woodlandsavanna biome) in eastern Mato Grosso, Brazil (Nova Xavantina District). Key results The group had a total home range of 140km2 (fixed kernel 95%), with smaller seasonal 'subareas' (areas used for 12 months before moving to another area, with repetition of some areas over time) and demonstrated a preference for native habitats. Conclusions The bush dog's home range is greater than that of other canids of the same size, even correcting for group size. Patterns of seasonal movement are also different from what has been observed in other South American canids. Implications From our observations in the Brazilian savanna, bush dogs need large tracks of native habitat for their long-term persistence. Although the present study is based on a single pack, it is highly relevant for bush dog conservation because it provides novel information on the species' spatial requirements and habitat preferences. © 2012 CSIRO.
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Brazil is the world leader in broiler production and export. It achieved this position mainly to its excellent supply chain structure and climate, which favor poultry and grain production throughout its territory. Although Brazilian egg production is not as important as broiler production, this segment presents great potential of increasing its share in the global market. However, as elsewhere in the world, Brazilian poultry production faces the challenge to balance two elements within its supply chain: cruelty and productivity. The consumers of the European Union (EU) are very concerned with animal welfare issues. In order to increase its share in the European market, and eventually in the world market, Brazilian poultry producers must understand the effects of production systems on poultry welfare, and try to develop systems that are suited for its climate and other production conditions. There is a consensus that the natural behaviors performed by poultry in intensive production systems allow better welfare. This objective of this review is to present scientific research studies that relate different behaviors to chicken welfare. Poultry behavior is a reflex of their welfare status at a particular moment, and it is related to internal (physiological) and external (environmental) factors. Several natural behaviors that favor welfare, as well as undesirable behaviors, may be stimulated by environmental enrichment. The correct interpretation of the behaviors expressed by poultry, including their frequency, duration, and sequence, may be used to estimate their welfare. Animal production is an import sector of Brazilian economy. It significantly contributes to the Gross Domestic Product (GDP), in terms of products destined both to domestic consumption and exports. New technologies applied to products and management practices have been developed for field application, aiming at improving producers' productivity and profitability. In order to comply with the European Union's (EU) guidelines for animal protein production, Brazilian poultry production needs to undergo a process of adaptation. In May, 2007, the EU Commission established its new guidelines for animal welfare in poultry production, pressured by consumer demand. In the EU, there is a growing concern among consumers as to how poultry are reared and slaughtered. European consumers are in the fore front of the demand of high quality products produced with under better welfare conditions, and have spread this concern throughout the world. Beaumont et al. (2010) mentioned that European consumers frequently perceive that standard commercial poultry production has poor animal welfare practices. According to Nääs et al. (2008), Brazilian poultry production today needs to find a balance between cruelty and productivity. In fact, ensuring animal welfare may provide better financial results, as it increases the producer's profit margins and allows maintaining Brazilian chicken export quotas to the EU. França (2008) noted that biological studies that define ethical limits and guidelines for poultry production foster the development of new production practices that may ensure good product quality and productivity without putting bird welfare at risk. Gonyou (1994) states that, when animal welfare started to be studied, the only behavioral factors considered were those related to feeding and reproduction. These first studies used as indicators of animal welfare reduced life expectancy, impaired growth, impaired reproduction, body damage, disease, immunosuppression, adrenal activity, behavior anomalies, and self-narcotization (Broom, 1991). However, current studies evaluate additional indicators, such as natural behaviors, behavioral needs, preferences, behavioral problems, emotional state, cognitive abilities, etc. In the field of ethology, the expression of natural behavior is a frequently used tool used to estimate the welfare of poultry destined to human consumption. According to Bracke & Hopster (2006), natural behavior can be defined as the behavior the animal normaly presents when exposed to conditions similar to its natural habitat. Natural behaviors are pleasurable and promote biological functions that are meaningful to the animal's welfare. The definition of natural behavior, though, does not include the bird's behavior when sick, in flight or during aggression, since these are not considered pleasurable situations. Considering layer behavioral needs in the design of housing facilities optimize their welfare. Mishra et al. (2005) verified that ISA Brown layers spent, during 24 hours, around 97% of the time in the nest, feeding, walking, resting, or dust bathing, and that 57% of these behaviors did not depend on environmental enrichment. It was also observed that hens had preferred behavioral sequences, which included foraging and comfort behaviors, such as wing-stretching and preening. The present review aims at discussing, albeit not exhaustively, scientific research studies on the behavior of Gallusgallus domesticus and its relationship to welfare. The following behaviors are reviewed: feather pecking, scratching, dust bathing, nesting, locomotion activities, and aggressive behaviors. These behaviors are the most frequently observed in commercial broiler, broiler breeder, and layer farming, and therefore, monitoring their incidence may contribute to measure poultry welfare.
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We studied patterns in the use of space for foraging and roosting by two frugivorous bat species in a five-year-old restored Atlantic forest located in a fragmented landscape in southeastern Brazil. Ten individuals of Carollia perspicillata and eleven individuals of Artibeus lituratus were monitored through radio-telemetry in five sampling sessions. Each session lasted 3-8. days for each individual, with an average of 25.4 ± 10 locations for each C. perspicillata individual and 19 ± 4.4 for each A. lituratus individual. We described an average range of 124.4. ha and an average commuting distance of 1158.8. m for A. lituratus and an average range and commuting distance of 32. ha and 489. m, respectively, for C. perspicillata. We demonstrated a consistent pattern in habitat use and movements for both studied species, where they strictly used forests (restored or not) for day roosting, roosting in the foliage of trees located only in secondary forest remnants and restored areas, while restored areas were their main feeding habitat. We demonstrate that newly restored forests can be readily incorporated as foraging and roosting habitats by these species, and that C. perspicillata alters its roosting behavior in relation to preferred food availability. These results, when combined with data on the diet of the studied species, show consistent evidence of the potential that bats have to improve species diversity of anthropogenic plantings with their own natural seed dispersal. © 2012 Elsevier B.V.
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Environmental factors strongly affect mangrove crabs, and some factors modulate population structure and habitat partitioning during the crabs' life cycle. However, the effect of these environmental factors on habitat selection by mangrove crabs is still unknown. We evaluated habitat selection by the mangrove crab Ucides cordatus in mangrove forests with different degrees of predominance of Rhizophora mangle, Laguncularia racemosa or Avicennia schaueriana, two tidal flooding levels (less- and more-flooded), and two biological periods (breeding and non-breeding seasons). Sampling was conducted in four mangrove forests with different influences of these biotic and abiotic parameters. We used the data for sex ratio to explain environmental partitioning by this species. Females predominated in R. mangle mangroves, independently of the biological period (breeding or non-breeding seasons), and males predominated only in the less-flooded L. racemosa mangroves. The flooding level affected the sex ratio of U. cordatus, with a predominance of males in less-flooded mangroves, independently of the biological period; and a gender balance in the more-flooded mangroves only during the breeding season. Outside the breeding season, the largest specimens were recorded in the R. mangle mangroves, but in the breeding season, the largest crabs were recorded in the L. racemosa mangroves with a higher level of flooding. These results suggest that tree-species composition and tidal flooding level can have a significant effect on the habitat partitioning of sexes and sizes of the mangrove crab U. cordatus both during and outside the breeding season. © 2012 Springer-Verlag and AWI.
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How individual-level movement decisions in response to habitat edges influence population-level patterns of persistence and spread of a species is a major challenge in spatial ecology and conservation biology. Here, we integrate novel insights into edge behavior, based on habitat preference and movement rates, into spatially explicit growth-dispersal models. We demonstrate how crucial ecological quantities (e.g., minimal patch size, spread rate) depend critically on these individual-level decisions. In particular, we find that including edge behavior properly in these models gives qualitatively different and intuitively more reasonable results than those of some previous studies that did not consider this level of detail. Our results highlight the importance of new empirical work on individual movement response to habitat edges. © 2013 by The University of Chicago.
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Habitat split is a major force behind the worldwide decline of amphibian populations, causing community change in richness and species composition. In fragmented landscapes, natural remnants, the terrestrial habitat of the adults, are frequently separated from streams, the aquatic habitat of the larvae. An important question is how this landscape configuration affects population levels and if it can drive species to extinction locally. Here, we put forward the first theoretical model on habitat split which is particularly concerned on how split distance - the distance between the two required habitats - affects population size and persistence in isolated fragments. Our diffusive model shows that habitat split alone is able to generate extinction thresholds. Fragments occurring between the aquatic habitat and a given critical split distance are expected to hold viable populations, while fragments located farther away are expected to be unoccupied. Species with higher reproductive success and higher diffusion rate of post-metamorphic youngs are expected to have farther critical split distances. Furthermore, the model indicates that negative effects of habitat split are poorly compensated by positive effects of fragment size. The habitat split model improves our understanding about spatially structured populations and has relevant implications for landscape design for conservation. It puts on a firm theoretical basis the relation between habitat split and the decline of amphibian populations. © 2013 Fonseca et al.
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The reproductive biology of a species includes factors beyond its sexual maturity, fecundity and reproductive period, and may extend to the differential distribution of individuals. The reproductive dynamics of the blue crab Callinectes ornatus was investigated through monthly collections over the course of 2 years in three bays on the southeastern coast of Brazil. For each bay, six transects were established, four of them parallel to the beach line (at depths of 5, 10, 15, and 20 m), one transect exposed to wave action, and another sheltered from waves. Females and males were classified according to the gonadal maturation stage, and were grouped as individuals with reproductive potential (mature gonads or breeding females) or not (rudimentary gonads or in development). Analyses using ordination techniques (PCA) and gradient analysis (CCA) showed that 82.13 % of environmental variations were explained by the transect arrangement, and these characteristics explained 86.70 % of the differential distribution of female crabs and 96.57 % of the distribution of males. These results indicate that females with reproductive potential were more abundant in deeper regions, while females with rudimentary or developed gonads were abundant in shallower habitats and areas sheltered from wave action. Thus, the distribution of C. ornatus in these bays was linked to their reproductive state, as part of the reproductive strategy of the population. © 2013 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg.
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The effectiveness of ecological restoration actions toward biodiversity conservation depends on both local and landscape constraints. Extensive information on local constraints is already available, but few studies consider the landscape context when planning restoration actions. We propose a multiscale framework based on the landscape attributes of habitat amount and connectivity to infer landscape resilience and to set priority areas for restoration. Landscapes with intermediate habitat amount and where connectivity remains sufficiently high to favor recolonization were considered to be intermediately resilient, with high possibilities of restoration effectiveness and thus were designated as priority areas for restoration actions. The proposed method consists of three steps: (1) quantifying habitat amount and connectivity; (2) using landscape ecology theory to identify intermediate resilience landscapes based on habitat amount, percolation theory, and landscape connectivity; and (3) ranking landscapes according to their importance as corridors or bottlenecks for biological flows on a broader scale, based on a graph theory approach. We present a case study for the Brazilian Atlantic Forest (approximately 150 million hectares) in order to demonstrate the proposed method. For the Atlantic Forest, landscapes that present high restoration effectiveness represent only 10% of the region, but contain approximately 15 million hectares that could be targeted for restoration actions (an area similar to today's remaining forest extent). The proposed method represents a practical way to both plan restoration actions and optimize biodiversity conservation efforts by focusing on landscapes that would result in greater conservation benefits. © 2013 Society for Ecological Restoration.
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In Brazil, the state of São Paulo contains both preserved areas (Juréia-Itatins Ecological Station) and extremely impacted ones (Cubatão Municipality). This study evaluated the concentrations of five metals (Cu, Cd, Cr, Pb, and Hg) in two mangroves with different levels of anthropogenic impact and the apparent genotoxicity to Ucides cordatus. Water and sediment samples were obtained, and metal concentrations were determined with an atomic absorption spectrophotometer. The genotoxic impact was quantified based on the number of micronucleated cells per 1,000 analyzed (MN‰), using hemolymph slides stained with Giemsa. Metal concentrations in water were below the detection limit, except for lead, although no significant difference was observed between the areas (P > 0.05). Sediment from Cubatão had higher concentrations of Cd, Pb, Cr, and Cu than sediment from Juréia-Itatins (P < 0.05), but no significant differences in metal concentrations were detected among depth strata of the sediment (P > 0.05). Crabs from Cubatão had a 2.6 times higher mean frequency of micronucleated cells (5.2 ± 1.8 MN‰) than those from Juréia-Itatins (2.0 ± 1.0 MN‰; P < 0.0001). The more-polluted conditions found in the mangrove sediments of Cubatão were reflected in the micronucleus assay, demonstrating their genotoxic effect; however, genetic damage should be attributed to a synergistic effect with other kinds of pollutants previously recorded in different environments of Cubatão. U. cordatus proved to be an excellent bioindicator of mangrove pollution. This study established, for the first time, the normal frequency of MN‰ in a population of this species within an ecological station. © 2013 Springer Science+Business Media Dordrecht.