Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Am J Primatol ; 84(12): e23447, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36314412

RESUMO

There are strong physiological and behavioral differences that allow animals to live in forests versus savannas. For example, terrestrial forest-dwelling mammals tend to be small compared to species living in savannas. Robust capuchin monkeys (genus Sapajus) are widespread in tropical South America, occurring in both forest and savanna environments, with forest species considered basal in an evolutionary context. Whether or not skull shape and size variations are associated with variation in resource use remains unknown, particularly for the two species living in savanna (Sapajus libidinosus and S. cay). Here we show that savanna species present convergent size and skull characteristics that may facilitate living in this new environment. Geometric morphometric methods were used to assess skull size and shape variation for 184 Sapajus specimens distributed across South America. We used phylogenetic generalized least squares to test size against environmental variables and multivariate morphological trajectories/partial least square analyses on the skull shape to detect shape differences in specimens between forest and savanna biomes. Our findings reveal Sapajus size reduction in the evolutionary transition from forest to savanna, a process related to increasing seasonality. Moreover, we found morphological parallelism in the skull (e.g., muzzle shortening) and (large) molars in the two savanna species, features that may facilitate the processing of harder food such as fallback resources. We associate these phenotypic differences to the evolutionary process of colonizing the savannas by primates (including early hominins), leading to morphological adaptations to tolerate stressful, seasonal environments, such as body size reduction and ingestion and mastication of tough foods.


Assuntos
Platirrinos , Sapajus , Animais , Pradaria , Filogenia , Haplorrinos , Florestas , Cebus , Mamíferos
2.
Am Nat ; 198(4): E111-E121, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34559610

RESUMO

AbstractAlthough many studies have shown that species richness increases from high to low latitudes (the latitudinal diversity gradient), the mechanisms responsible for generating and maintaining higher species richness in the tropics remain intensely debated. Here we investigate how the effects of temperature on speciation rates (kinetic effects) and the effects of productivity on community size (chemical effects) explain the latitudinal diversity gradient of South American small mammals. We implemented Bayesian models that integrate processes from the neutral and metabolic theories, comparing model predictions with empirical richness patterns. The neutral-metabolic model predicted the latitudinal richness gradient in South American small mammals. We found evidence that the effects of productivity on community size are more important for explaining differences in species richness than the effects of temperature on speciation rates. These results suggest that differences in species richness along latitudinal gradients are regulated primarily by the chemical effects of productivity on speciation-extinction dynamics.


Assuntos
Biodiversidade , Especiação Genética , Animais , Teorema de Bayes , Mamíferos , América do Sul
3.
Evolution ; 74(9): 2046-2058, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32395852

RESUMO

Geographical distribution of color phenotypes and associations with ecological predictors remains poorly understood. An important geographic pattern concerning this topic is Gloger's rule, which predicts the increase of pigmentation in endothermic animals from cold and dry to warm and wet environments. Didelphid marsupials exhibit a variety of color patterns, ranging from light and dark uniform to more complex colorations. However, surprisingly little is known about the adaptive significance of dark coloration in this singular group of mammals. Using a phylogenetic comparative approach, we investigated whether coloration in different body regions of didelphids (i.e., dorsum and face) is associated with variables representing heat and humidity of the environment, as predicted by Gloger's rule. We demonstrated that Gloger's rule explains the interspecific color variation in American marsupials, especially when considering the facial region. Thus, dark coloration was more frequent among didelphid species occupying warm and wet environments than cold and dry environments. We also discuss the selective forces that can potentially explain coat color variation in didelphid marsupials, including camouflage, pathogen resistance, and pleiotropy hypotheses.


Assuntos
Evolução Biológica , Marsupiais/fisiologia , Pigmentação , Animais , Cor , América do Norte , Fenótipo , Filogenia , América do Sul
4.
PLoS One ; 14(12): e0226136, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31851714

RESUMO

Melanism in the cat family has been associated with functions including camouflage, thermoregulation and parasite resistance. Here we investigate a new hypothesis proposing that the evolution of melanism in cats has additionally been influenced by communication functions of body markings. To evaluate this hypothesis, we assembled a species-level data set of morphological (body marks: white marks on the backs of ears) and ecological (circadian activity: arrhythmic/nocturnal, and environmental preference: open/closed) characteristics that could be associated with communication via body markings, and combined these data with a dated molecular phylogeny. Next, we tested the association between melanism and communication, first by relating species' body marks with their ecological conditions, using a Bayesian implementation of the threshold model. Second, to explore the evolution of characteristics potentially influencing melanism in cat species, we modeled their evolution relative to melanism using models of coordinated vs. independent character changes. Our results suggest that white marks are associated with intraspecific communication between individuals that have non-melanistic phenotypes, as well as towards melanistic individuals (without white marks). The absence of white marks in a melanistic individual tends to be a limiting condition for intraspecific visual communication at night, resulting in an evolutionary dilemma for these species, i.e. to be almost invisible at night, but not to communicate visually. The comparative analysis of several evolutionary models indicated more support for the evolution of melanism being coordinated with the evolution of arrhythmic activity and white marks on the backs of ears.


Assuntos
Evolução Biológica , Felidae , Cor de Cabelo , Melaninas , Comunicação Animal , Animais , Gatos , Modelos Biológicos
5.
Ecology ; 100(10): e02785, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31180132

RESUMO

Biodiversity inventories contain important information about species richness, community structure, and composition, and are the first step in developing any conservation and mitigation strategies. The Atlantic Forest of South America is home to around 334 species of small-, medium-, and large-sized mammals, and is currently restricted to less than 12% of its original cover. Here, we present the ATLANTIC MAMMALS, an open data set on information on medium- and large-sized mammal assemblages in the Atlantic Forest of Brazil, Paraguay, and Argentina. A total of 129 studies were compiled, including published and in press peer-reviewed papers, book chapters, theses and unpublished data. We mapped 244 assemblages, eight orders, 63 genera, and 94 species (24 of which are classified as threatened by the IUCN Red List) distributed in 128 protected and 116 unprotected areas. Species richness of the mammalian assemblages varied from 1 to 39 species (mean 15). The most recorded species in the entire biome was Dasypus novemcinctus, followed by Cerdocyon thous and Procyon cancrivorous. These data can be useful in support of macroecological studies and conservation planning strategies. Please cite this data paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data.

6.
Ecology ; 99(2): 498, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29399824

RESUMO

Measures of traits are the basis of functional biological diversity. Numerous works consider mean species-level measures of traits while ignoring individual variance within species. However, there is a large amount of variation within species and it is increasingly apparent that it is important to consider trait variation not only between species, but also within species. Mammals are an interesting group for investigating trait-based approaches because they play diverse and important ecological functions (e.g., pollination, seed dispersal, predation, grazing) that are correlated with functional traits. Here we compile a data set comprising morphological and life history information of 279 mammal species from 39,850 individuals of 388 populations ranging from -5.83 to -29.75 decimal degrees of latitude and -34.82 to -56.73 decimal degrees of longitude in the Atlantic forest of South America. We present trait information from 16,840 individuals of 181 species of non-volant mammals (Rodentia, Didelphimorphia, Carnivora, Primates, Cingulata, Artiodactyla, Pilosa, Lagomorpha, Perissodactyla) and from 23,010 individuals of 98 species of volant mammals (Chiroptera). The traits reported include body mass, age, sex, reproductive stage, as well as the geographic coordinates of sampling for all taxa. Moreover, we gathered information on forearm length for bats and body length and tail length for rodents and marsupials. No copyright restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data.

7.
PLoS One ; 11(6): e0157723, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27336371

RESUMO

Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allopatric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology. For this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might share their geographic space. Little is known about how two morphologically similar species of marsupials may affect each other through competition, if by competitive exclusion and competitive release. We combined ecological niche modeling and geometric morphometrics to explore the possible effects of competition on their distributional ranges and skull morphology. Ecological niche modeling was used to predict their potential distribution and this method enabled us to identify a case of biotic exclusion where the habit generalist D. albiventris is excluded by the presence of the specialist D. aurita. The morphometric analyses show that a degree of shape discrimination occurs between the species, strengthened by allometric differences, which possibly allowed them to occupy marginally different feeding niches supplemented by behavioral shift in contact areas. Overlap in skull morphology is shown between sympatric and allopatric specimens and a significant, but weak, shift in shape occurs only in D. aurita in sympatric areas. This could be a residual evidence of a higher past competition between both species, when contact zones were possibly larger than today. Therefore, the specialist D. aurita acts a biotic barrier to D. albiventris when niche diversity is not available for coexistence. On the other hand, when there is niche diversification (e.g. habitat mosaic), both species are capable to coexist with a minimal competitive effect on the morphology of D. aurita.


Assuntos
Didelphis/fisiologia , Animais , Constituição Corporal , Tamanho Corporal , Comportamento Competitivo , Didelphis/anatomia & histologia , Ecossistema , Feminino , Masculino , Modelos Biológicos , Filogeografia , Crânio/anatomia & histologia , América do Sul
8.
Evol Biol ; 43: 145-159, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27217595

RESUMO

Species morphological changes can be mutually influenced by environmental or biotic factors, such as competition. South American canids represent a quite recent radiation of taxa that evolved forms very disparate in phenotype, ecology and behaviour. Today, in the central part of South America there is one dominant large species (the maned wolf, Chrysocyon brachyurus) that directly influence sympatric smaller taxa via interspecific killing. Further south, three species of similar sized foxes (Lycalopex spp.) share the same habitats. Such unique combination of taxa and geographic distribution makes South American dogs an ideal group to test for the simultaneous impact of climate and competition on phenotypic variation. Using geometric morphometrics, we quantified skull size and shape of 431 specimens belonging to the eight extant South American canid species: Atelocynus microtis, Cerdocyon thous, Ch. brachyurus, Lycalopex culpaeus, L. griseus, L. gymnocercus, L. vetulus and Speothos venaticus. South American canids are significantly different in both skull size and shape. The hypercarnivorous bush dog is mostly distinct in shape from all the other taxa while a degree of overlap in shape-but not size-occurs between species of the genus Lycalopex. Both climate and competition impacts interspecific morphological variation. We identified climatic adaptations as the main driving force of diversification for the South American canids. Competition has a lower degree of impact on their skull morphology although it might have played a role in the past, when canid community was richer in morphotypes.

9.
Evolution ; 69(7): 1690-700, 2015 07.
Artigo em Inglês | MEDLINE | ID: mdl-26095445

RESUMO

Chewing on different food types is a demanding biological function. The classic assumption in studying the shape of feeding apparatuses is that animals are what they eat, meaning that adaptation to different food items accounts for most of their interspecific variation. Yet, a growing body of evidence points against this concept. We use the primate mandible as a model structure to investigate the complex interplay among shape, size, diet, and phylogeny. We find a weak but significant impact of diet on mandible shape variation in primates as a whole but not in anthropoids and catarrhines as tested in isolation. These clades mainly exhibit allometric shape changes, which are unrelated to diet. Diet is an important factor in the diversification of strepsirrhines and platyrrhines and a phylogenetic signal is detected in all primate clades. Peaks in morphological disparity occur during the Oligocene (between 37 and 25 Ma) supporting the notion that an adaptive radiation characterized the evolution of South American monkeys. In all primate clades, the evolution of mandible size is faster than its shape pointing to a strong effect of allometry on ecomorphological diversification in this group.


Assuntos
Evolução Biológica , Mandíbula/anatomia & histologia , Primatas/anatomia & histologia , Animais , Dieta , Feminino , Fósseis/anatomia & histologia , Masculino , Mastigação , Filogenia , Primatas/fisiologia , Especificidade da Espécie
10.
Exp Appl Acarol ; 66(3): 369-81, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25912954

RESUMO

We describe ectoparasite fauna associated with small mammals in fragments of Cerrado biome, central-western Brazil. We analyzed the level of associations and the aggregation patterns according to seasonal and host variations. Small mammals were systematically captured in 54 woodland fragments from February 2012 to July 2013. A total of 1040 animals belonging to eight marsupial and 12 rodent species were sampled; 354 individuals were parasitized by 33 ectoparasite species (twenty five Mesostigmata, seven Phthiraptera and one Siphonaptera). A total of 49 ecological relationships between ectoparasites and small mammals were observed, 24 being new association records. The overall specialization index of all ectoparasites and host species was 0.91 with significant deviation from a random host-parasite association, suggesting a high host-parasite specialization in this system. Specialization indices for ectoparasites ranged from moderate to high, while among host was high, for most species. Contrary to the overall pattern, some ectoparasites had higher prevalence and mean intensity of infestation in the dry season. Overall, ectoparasite prevalence and mean intensity of infestation were not significantly associated with host gender. This study provides significant information about the ectoparasites ecology in relation to specificity, seasonality and hosts gender, contributing to the understanding of host-parasite relationships in Brazilian savannah.


Assuntos
Infestações por Pulgas/veterinária , Interações Hospedeiro-Parasita , Infestações por Piolhos/veterinária , Marsupiais , Infestações por Ácaros/veterinária , Doenças dos Roedores/epidemiologia , Ácaros e Carrapatos/fisiologia , Animais , Brasil/epidemiologia , Feminino , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/parasitologia , Pradaria , Especificidade de Hospedeiro , Infestações por Piolhos/epidemiologia , Infestações por Piolhos/parasitologia , Masculino , Infestações por Ácaros/epidemiologia , Infestações por Ácaros/parasitologia , Ftirápteros/fisiologia , Doenças dos Roedores/parasitologia , Roedores , Sifonápteros/fisiologia
11.
Exp Appl Acarol ; 65(3): 389-401, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25633262

RESUMO

The present study describes ticks associated with small mammals and analyzes the aggregation patterns according to seasonal and host variations in the Cerrado biome, central-western Brazil. Small mammals were systematically captured in 54 woodland fragments from February 2012 to July 2013. A total of 1,040 animals belonging to eight marsupial and 12 rodent species were captured; 265 animals were parasitized by eight tick species (in decreasing order of abundance): Ornithodoros mimon, Amblyomma coelebs, Amblyomma sculptum, Amblyomma ovale, Amblyomma parvum, Amblyomma dubitatum, Amblyomma parkeri, and Ixodes amarali. With few exceptions, collected ticks were larvae and nymphs. Among the more abundant animals, the marsupial Didelphis albiventris showed the highest tick prevalence (84.4 %), mean abundance (19.2), mean intensity (22.8), richness of ticks species (n = 7), and total abundance of ticks (n = 2,457). Amblyomma sculptum and O. mimon were the most generalist species, collected on four host species. Fifteen new tick-host associations are reported for the first time. Most ticks showed higher prevalence and mean intensity in the dry season, regardless of host species. Overall, tick prevalence and mean intensity of infestation were significantly associated with host gender. Finally, the importance of the large number of records of the argasid O. mimon is discussed.


Assuntos
Argasidae , Ixodidae , Marsupiais/parasitologia , Roedores/parasitologia , Animais , Brasil , Feminino , Masculino , Estações do Ano , Fatores Sexuais
12.
An Acad Bras Cienc ; 85(2): 727-36, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23828340

RESUMO

Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.


Assuntos
Ecossistema , Marsupiais/classificação , Roedores/classificação , Árvores , Animais , Brasil , Estações do Ano
13.
Biota neotrop. (Online, Ed. port.) ; 11(3): 403-406, jul.-set. 2011. ilus, mapas
Artigo em Inglês | LILACS | ID: lil-610586

RESUMO

The exotic alien species Axis axis was introduced in the Americas at the beginning of last century and since then has established itself, expanding its distribution. This is the first record of this species in Brazil. In the extreme south of the country, an individual of A. axis was recorded with a camera trap in the Espinilho State Park. The area is close to the border of Uruguay and Argentina, countries where the species is established and from where this individual presumably originated. The Pampas biome is strongly disturbed by human activity in Brazil and since many native mammal species such as the Pampas deer Ozotoceros bezoarticus are threatened regionally. It is alarming that exotic populations can potentially rapidly expand their ranges in the region, as A. axis deer has done in Uruguay and Argentina. Possible consequences for this invasion are discussed.


A espécie exótica invasora Axis axis foi introduzida no continente americano no início do século passado e desde então se estabeleceu, ampliando sua distribuição. Este é o primeiro registro da espécie para o Brasil. No extremo sul do país, um indivíduo de A. axis foi registrado com armadilha fotográfica, no Parque Estadual do Espinilho. A área é muito próxima a divisa com Uruguai e Argentina, países onde a espécie esta estabelecida e de onde provavelmente o espécime é originário. Visto que o bioma Pampa encontra-se fortemente alterado no Brasil e que muitas espécies da fauna de mamíferos nativa estão ameaçadas de extinção regionalmente, como o veado-campeiro Ozotoceros bezoarticus, é preocupante que populações exóticas estejam ampliando rapidamente sua área de distribuição na região, como fez A. axis no Uruguai e Argentina. Possíveis implicações decorrentes dessa invasão são discutidas.

14.
Cien Saude Colet ; 15(5): 2611-20, 2010 Aug.
Artigo em Português | MEDLINE | ID: mdl-20802893

RESUMO

This study had the aim to verify the necessities of training and improvement of the 4th Regional Coordination in Health of Rio Grande do Sul State family health teams. The data collection was carried out through the application of questionnaires with objective questions, composed by two parts: field and competence nucleus. For data analyses, Normality, Chi-Square and G tests were used as statistical procedures for Easy and Difficult attributions indicated by the professionals. Professionals have shown less difficulty with generic attributions, related with basic methods and techniques of each health area. However, they have revealed a lot of difficulties with attributions relating to the search of new partners in health inside communities, stimulation of the people participation in the discussion of health rights, and completion of the SIA/SIAB forms, and others. Even after 12 years of the foundation of the Family Health Program (PSF), several difficulties are still observed concerning the way to work with this new health strategy in Brazil. Proposals are made for the complete understanding and improvement of the PSF strategy.


Assuntos
Saúde da Família , Programas Governamentais , Adulto , Brasil , Feminino , Programas Governamentais/educação , Programas Governamentais/normas , Pessoal de Saúde/educação , Pessoal de Saúde/normas , Humanos , Masculino , Recursos Humanos , Adulto Jovem
15.
Ciênc. Saúde Colet. (Impr.) ; 15(5): 2611-2620, ago. 2010. tab
Artigo em Português | LILACS | ID: lil-555617

RESUMO

Este estudo objetivou verificar as necessidades para a capacitação e aperfeiçoamento dos profissionais das equipes de saúde da família dos 31 municípios que compõe a 4ª Coordenadoria Regional de Saúde do Estado do Rio Grande do Sul. A coleta de dados foi realizada através da aplicação de um questionário com questões objetivas, composto de duas partes: campo e núcleo de competências. Para análise dos dados obtidos, foram utilizados testes de normalidade, qui-quadrado e teste G para as atribuições fáceis e difíceis indicadas pelos profissionais. Os profissionais mostraram menores dificuldades com atribuições genéricas, relacionadas a métodos e técnicas básicas de cada área de formação. Porém, revelaram dificuldades tais como a busca de parcerias nas comunidades, estimulação da participação popular na discussão sobre direitos à saúde e o preenchimento dos formulários do SIA/SIAB. Mesmo após doze anos da criação do Programa de Saúde da Família (PSF), observam-se ainda várias dificuldades em atuar de forma adequada e necessária a este novo modelo de trabalho em saúde. São propostas medidas que visam auxiliar e consolidar o PSF em seus diversos níveis.


This study had the aim to verify the necessities of training and improvement of the 4th Regional Coordination in Health of Rio Grande do Sul State family health teams. The data collection was carried out through the application of questionnaires with objective questions, composed by two parts: field and competence nucleus. For data analyses, Normality, Chi-Square and G tests were used as statistical procedures for Easy and Difficult attributions indicated by the professionals. Professionals have shown less difficulty with generic attributions, related with basic methods and techniques of each health area. However, they have revealed a lot of difficulties with attributions relating to the search of new partners in health inside communities, stimulation of the people participation in the discussion of health rights, and completion of the SIA/SIAB forms, and others. Even after 12 years of the foundation of the Family Health Program (PSF), several difficulties are still observed concerning the way to work with this new health strategy in Brazil. Proposals are made for the complete understanding and improvement of the PSF strategy.


Assuntos
Adulto , Feminino , Humanos , Masculino , Adulto Jovem , Saúde da Família , Programas Governamentais , Brasil , Programas Governamentais/educação , Programas Governamentais/normas , Pessoal de Saúde/educação , Pessoal de Saúde/normas , Adulto Jovem
16.
Braz. arch. biol. technol ; 50(6): 921-928, Nov. 2007. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-476218

RESUMO

Seed germination in plant species consumed by opossums, genus Didelphis, was investigated in southern Brazil, in order to improve knowledge of the strategies of zoochorous plants in the Neotropics. Seeds were obtained from opossum feces. Thirteen of the most frequent species in the diet of local opossums were tested for germination rates and germination responses under different qualities (red/far red ratio) and different intensities of light. Most seeds from feces germinated similarly to the control groups, except for seeds of Rubus rosifolius, which appeared to depend on gut passage. Other experiments revealed that most seeds in the opossums' diet were of pioneer species, with most germination occurring during favorable humid conditions in the rainy season. A few species showed negative photoblastism, or no dormancy pattern. Small mammals are suggested as possible tools for area recuperation programs, through seed dispersal of many pioneer and some shade-tolerant plants, under suitable management.


Com o objetivo de fornecer conhecimento adicional acerca das estratégias de germinação adotadas por espécies de plantas zoocóricas da Região Neotropical, foram examinadas a dormência e germinação de sementes consumidas por marsupiais do gênero Didelphis. As sementes foram obtidas de fezes dos animais capturados em armadilhas, sendo então analisadas. As espécies mais freqüentes na dieta dos gambás (N = 13) foram testadas quanto a sua viabilidade e possíveis mecanismos de quebra de dormência pela luz (condições de luz vs. sombra vs. escuro; e sob red/far red ratio). A maioria das espécies provenientes das fezes germinou similarmente ao grupo controle, exceto por Rubus rosifolius que parece depender da passagem pelo trato digestivo para a germinação. Outros experimentos mostraram que as espécies de plantas eram principalmente pioneiras, com quebra de dormência principalmente durante a estação mais úmida e favorável ao desenvolvimento. Uma menor proporção de espécies apresentou fotoblastismo negativo ou nenhum padrão de dormência. Os resultados mostram que estes pequenos mamíferos podem ser utilizados em programas de recuperação de áreas degradadas, com enfoque na dispersão de sementes de plantas pioneiras

17.
Artigo em Português | LILACS | ID: lil-468016

RESUMO

Este estudo tem por objetivo registrar a ocorrência de quatro espécies de morcegos na região central do Estado do Rio Grande do Sul, sul do Brasil: Histiotus montanus, Pygoderma bilabiatum, Nyctinomops laticaudatus e Myotis ruber. Os dados foram obtidos a partir da coleção científica da Universidade Federal de Santa Maria (UFSM) e representam ampliações de distribuição para essas espécies no Estado. São fornecidas informações sobre o habitat onde as espécies foram coletadas, sendo que alguns desses são novos para essas espécies. Pode-se considerar que algumas das espécies enfocadas são raras no Rio Grande do Sul, ao passo que outras deveriam ter o seu grau de ameaça reconsiderado.


The objective of this paper is to record the occurrence of four bats species in the central of the Rio Grande do Sul State, south of Brazil: Histiotus montanus, Pygoderma bilabiatum, Nyctinomops laticaudatus and Myotis ruber. Data were obtained from the scientific collection of Universidade Federal de Santa Maria (UFSM) and represent distribution extensions for these bat species in this State. We present information on the habitat where the species were collected, showing that some of them are new for this species. Some of the studied species may be considered rare in the Rio Grande do Sul State, whereas others should have their degree of threat revaluated.


Assuntos
Biodiversidade , Ecologia , Ecossistema/análise , Ecossistema/classificação , Quirópteros/classificação , Quirópteros/crescimento & desenvolvimento , Árvores
18.
Rev. biol. trop ; 54(4): 1197-1203, dic. 2006. tab, graf
Artigo em Inglês | LILACS | ID: lil-492162

RESUMO

A two year study of dung beetles and ants acting on scats of two species of opossum (Didelphis spp.) was carried out. Scats were left in the field in order to detect post-dispersal agents. A portion of each scat (30 %) was examined for seeds in the laboratory. Beetles were recovered from burrows (51% of 84 faecal samples left in the field) where they either buried scats of opossums or were attracted, together with ants, to pitfalls (N = 10) baited with opossum scats. Dung beetles were the main post-dispersal agents of seeds found in scats of opossums, rolling the scats away or burying then on the site of deposition. They buried faeces at 4 to 15 cm in depth (N = 22 tunnels). The main dung beetles identified (medium to large size) were Eurysternus (28.7 % in pitfalls) and Dichotomius (13.7 %), Coprophanaeus (seen only directly on faeces), besides small-bodied beetles (< 10 mm; 57.6 %). The ant Acromirmex sp. transported some seeds from scats. This species was present in 25.5 % of all Formicidae samples (pitfall). These post-dispersal agents contribute to avert scat seed predators such as rodents, and to accelerate seed bank formation.


Por dos años estudiamos los escarabajos coprófagos y las hormigas que actúan en las heces de zarigüellas (Didelphis). Se dejaron excrementos en el campo para descubrir los agentes secundarios de dispersión. Una parte de cada excremento (30 %) fue analizada en laboratorio para estimar el número de semillas. Se recolectaron escarabajos del suelo (51 % de 84 excrementos dejados en el campo). También capturamos escarabajos y hormigas con trampas (N= 10). Los escarabajos coprófagos son los principales agentes secundarios de dispersión. Ruedan los excrementos o los entierran a 4-15 cm de profundidad (N= 22 túneles). Los escarabajos coprófagos de mayor tamaño fueron Eurysternus cyanescens (28.7 % en trampas), Dichotomius assifer (13.7 %) y Coprophanaeus saphirinus (sólo visto en madrigueras y directamente sobre los excrementos). Los escarabajos de menos de 10 mm fueron el 57.6 %. La hormiga Acromirmex sp. fue 25.5 % del total de hormigas capturadas en trampas. Hallamos varias especies de semillas en los excrementos, muchos de ellos enterrados por los escarabajos, y algunas fueron extraídas por las hormigas. Estos agentes secundarios ayudan a evitar los depredadores de semillas (eg. roedores) y aceleran la formación del banco de semillas, pues no las comen.


Assuntos
Animais , Besouros/fisiologia , Comportamento Animal/fisiologia , Formigas/fisiologia , Gambás/fisiologia , Sementes/crescimento & desenvolvimento , Fezes
19.
Rev Biol Trop ; 54(4): 1197-203, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18457158

RESUMO

A two year study of dung beetles and ants acting on scats of two species of opossum (Didelphis spp.) was carried out. Scats were left in the field in order to detect post-dispersal agents. A portion of each scat (30 %) was examined for seeds in the laboratory. Beetles were recovered from burrows (51% of 84 faecal samples left in the field) where they either buried scats of opossums or were attracted, together with ants, to pitfalls (N = 10) baited with opossum scats. Dung beetles were the main post-dispersal agents of seeds found in scats of opossums, rolling the scats away or burying then on the site of deposition. They buried faeces at 4 to 15 cm in depth (N = 22 tunnels). The main dung beetles identified (medium to large size) were Eurysternus (28.7 % in pitfalls) and Dichotomius (13.7 %), Coprophanaeus (seen only directly on faeces), besides small-bodied beetles (< 10 mm; 57.6 %). The ant Acromirmex sp. transported some seeds from scats. This species was present in 25.5 % of all Formicidae samples (pitfall). These post-dispersal agents contribute to avert scat seed predators such as rodents, and to accelerate seed bank formation.


Assuntos
Formigas/fisiologia , Comportamento Animal/fisiologia , Besouros/fisiologia , Gambás/fisiologia , Sementes/crescimento & desenvolvimento , Animais , Fezes
20.
Biota neotrop. (Online, Ed. port.) ; 6(2): 0-0, 2006. ilus, tab
Artigo em Português | LILACS | ID: lil-447615

RESUMO

As primeiras informações sobre moscas ectoparasitas de morcegos e seus hospedeiros no estado do Mato Grosso do Sul são apresentadas. Os indivíduos de morcegos e de dípteros ectoparasitos foram coletados em área transicionais de cerrado e floresta estacional semidecídua, e também em uma floresta decídua. Foram encontradas sete espécies de Streblidae e uma de Basilia Miranda-Ribeiro, 1903 (Nycteribiidae). Todos os registros são inéditos para o estado do Mato Grosso do Sul e Basilia bequaerti Guimarães & DïAndretta, 1956 é registrada pela primeira vez no Brasil.


The first information on species of bat flies and their hosts in the state of Mato Grosso do Sul is given. The specimens of bats and bat flies were collected in a transitional area of cerrado and semideciduous forest and in a deciduous forest. Seven species of streblid and one of nicteribiid flies were collected on five species of bats. All bat flies are recorded for the first time in Mato Grosso do Sul and Basilia bequaerti Guimarães & DïAndretta, 1956 is a new record for Brazil.


Assuntos
Fauna/análise , Fauna/classificação , Fauna/efeitos adversos , Flora/análise , Flora/classificação , Flora/efeitos adversos , Parasitos/classificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...