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Distribuição e abundância de anfíbios e répteis neotropicais em paisagem silvicultural em São Paulo, Brasil; Distribution and abundance of neotropical amphibians and reptiles in silvicultural landscape in Sao Paulo, Brazil

Lopes, Paula Caroline
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/10/2010 PT
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37.19%
A maioria dos estudos sobre biodiversidade realizados no Brasil é desenvolvida em remanescentes de vegetação nativa. Entretanto, estudos recentes sugerem que paisagens agrícolas suportam uma considerável biodiversidade. O estado de São Paulo, região sudeste do Brasil, apresenta extensas áreas de pastagens, ainda sendo este o seu principal uso de solo, seguido por canaviais e eucaliptais. Este estudo foi desenvolvido nas Fazendas Três Lagoas e Arca, localizadas na bacia do Alto Paranapanema. A área inicialmente utilizada como pastagem (Brachiaria spp.) foi parcialmente substituída por plantações de eucalipto durante o período de agosto de 2006 a fevereiro de 2008. Neste estudo foram levantados anfíbios e répteis em 30 unidades amostrais contendo armadilhas de interceptação e queda distando um quilômetro uma das outras. Foram amostrados três ambientes distintos: eucaliptal (18 unidades amostrais), vegetação nativa (7 unidades amostrais) e pastos abandonados (5 unidades amostrais), resultando num esforço total de 4.977 armadilhas·dia em 23 campanhas mensais, entre agosto de 2007 e julho de 2009. Para análises dos dados foram consideradas como variável independente os ambientes (eucaliptais, pastos abandonados e vegetação nativa) e como variáveis dependentes a riqueza e abundância de anfíbios coletados nas armadilhas. Foram detectadas nas armadilhas 23 espécies...

Composição, riqueza e abundância de anfíbios e répteis no Alto e Médio Paranapanema, estado de São Paulo.; Composition, species richness and abundance of amphibians and reptiles in the Upper and Middle Paranapanema, São Paulo state, Brazil.

Araujo, Cybele de Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/04/2012 PT
Relevância na Pesquisa
36.88%
O objetivo deste estudo foi coletar e reunir informações sobre a diversidade de anfíbios e répteis nas bacias hidrográficas do Alto e Médio Paranapanema, estado de São Paulo e avaliar os impactos que o pastoreio de gado pode provocar na riqueza e abundância de anuros e lagartos de formações abertas de Cerrado. A riqueza de anuros registrada no Alto Paranapanema é muito superior a encontrada no Médio Paranapanema, existindo um gradiente decrescente na riqueza de espécies partindo da porção sul e sudeste do Alto Paranapanema, onde predominam a floresta ombrófila, em direção ao Médio Paranapanema que apresenta formações de Cerrado e floresta estacional. O pastoreio de gado não causou efeitos negativos na riqueza e abundância total dos anuros e lagartos amostrados. É possível que a intensidade de pastoreio ocorrida nestas formações não foi suficiente para promover modificações consideráveis na estrutura das fitofisionomias, o que pode ter minimizado alterações nos nichos ecológicos das espécies.; The aim of this study is to collect information on the diversity of amphibians and reptiles in the hydrographic basins of the Upper and Middle Paranapanema, São Paulo state and assess the impact that cattle grazing can provoke on the species richness and abundance of anurans and lizards of open Cerrado formations. The species richness of anurans reported in the Upper Paranapanema is far greater to that found in the Middle Paranapanema...

Patologia comparada de infecções selecionadas de anfíbios anuros de vida livre do bioma da Mata Atlântica: estudo prospectivo; Comparative pathology of selected infections of free living anuran amphibians from the Atlantic Forest biome: prospective study

Paula, Catia Dejuste de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 03/08/2011 PT
Relevância na Pesquisa
37.03%
Os anfíbios apresentaram um severo declínio de suas populações nas últimas décadas. Dentre as diversas causas dos declínios estão as doenças infecciosas. O presente trabalho tem o objetivo de estudar a ocorrência de enfermidades selecionadas que podem acometer estes animais na Mata Atlântica brasileira, e, desta forma, contribuir para a melhor compreensão das conseqüências destas enfermidades para a conservação dos anfíbios em nosso meio. Foram coletados 120 animais da Estação Biológica da Boracéia e realizaram-se exames necroscópicos, histopatológicos, microbiológicos, parasitológicos e PCR convencional para Batrachochytrium dendrobatidis em grande parte dos animais. Coletou-se 33 espécies diferentes pertencentes a sete famílias diferentes. Encontrou-se, no exame necroscópico, endoparasitas em 45,8% (55/120) dos espécimes examinados e ectoparasita (sanguessuga) em um espécime. Do total de animais analisados para Batrachochytrium dendrobatidis, 19,1% (22/115) foram positivos para Bd. O exame necroscópico assim como o histopatologicos da grande maioria dos animais estudados não exibiu alterações relevantes, sendo que os sistemas mais acometidos foram o digestório e tegumentar seguidos pelos urinário e linfóide. A somatória dos resultados aqui exibidos sugere que...

Nucleus isthmi and control of breathing in amphibians

Gargaglioni, L. H.; Branco, LGS
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 177-186
ENG
Relevância na Pesquisa
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Despite recent advances, the mechanisms of neurorespiratory control in amphibians are far from understood. One of the brainstem structures believed to play a key role in the ventilatory control of anuran amphibians is the nucleus isthmi (NI). This nucleus is a mesencephalic structure located between the roof of the midbrain and the cerebellum, which differentiates during metamorphosis; the period when pulmonary ventilation develops in bullfrogs. It has been recently suggested that the NI acts to inhibit hypoxic and hypercarbic drives in breathing by restricting increases in tidal volume. This data is similar to the influence of two pontine structures of mammals, the locus coeruleus and the nucleus raphe magnus. The putative mediators for this response are glutamate and nitric oxide. Microinjection of kynurenic acid (an ionotropic receptor antagonist of excitatory amino acids) and L-NAME (a non-selective NO synthase inhibitor) elicited increases in the ventilatory response to hypoxia and hypercarbia. This article reviews the available data on the role of the NI in the control of ventilation in amphibians. (C) 2004 Elsevier B.V. All rights reserved.

Análise de múltiplas ameaças à conservação e diversidade de anfíbios; Assessment of multiple threats to conservation and diversity of amphibians

Igor Soares de Oliveira
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/04/2015 PT
Relevância na Pesquisa
37.03%
As mudanças climáticas possuem potencial para alterar o funcionamento dos ecossistemas através da extinção de espécies e das conexões entre a biota e o ambiente, alterando os padrões aos quais estamos acostumados e exigindo adaptação. As alterações climáticas terão como uma de suas consequências a elevação oceânica, que pode redesenhar as costas de todos os continentes terrestres e afetar a biota associada. Nesse contexto, sobressaem-se os anfíbios como um grupo sensível que sofre diversas pressões e apresenta declínios populacionais, se destacando como vertebrados mais ameaçados da atualidade, com diversas espécies pouco conhecidas. Sendo assim, nesse trabalho analisamos múltiplos efeitos que dificultam a conservação dos anfíbios. Avaliamos os potenciais efeitos das mudanças climáticas e da elevação oceânica sobre os anfíbios com distribuição costeira. Também desenvolvemos um índice para classificar espécies com dados insuficientes com a finalidade de oferecer uma alternativa para a busca de informações para esses taxa e mudar sua classificação atual. Por fim, analisamos a disponibilidade histórica de clima adequado para uma linhagem endêmica do fungo quitrídio em busca de padrões que pudessem explicar sua distribuição e raridade atuais. Utilizamos ferramentas como modelos de distribuição de espécies e sistema de informação geográfica em busca de respostas às nossas questões. Nossos resultados corroboram as mudanças climáticas como um fenômeno com potencial devastador e alertam para potenciais perigos da elevação oceânica. Além disso...

Short term toxicity of nanomaterials in different development stages of amphibians; Toxicidade de nanomateriais em diferentes estádios do ciclo de vida de anfíbios

Costa, Nuno Mouta Faria da
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
ENG
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The production of engineered nanomaterials is rising and constantly growing. The fast advances in this industry are causing the introduction of nanomaterials (NMs) into the environment, namely into aquatic ecosystems. The specific properties that these new compounds exhibit may promote higher toxicity to biota, comparatively to their bulk counterparts. Size, charge, surface area, aggregation index, among others, may dictate the availability and the degree of toxicity of NMs in aquatic environments, especially when assembled with environmental changing conditions such as pH and temperature. Amphibians are excellent bioindicators to study the risk associated with the release of NM into the aquatic environment, since they inhabit a wide variety of freshwater habitats associated with industrial contamination. The present work intended to study the toxicity of NMs to different life stages of amphibians, concerning the increase of global temperature that is currently taking place. In order to achieve this, two specific goals were determined: i) evaluate the influence of temperature in the toxicity of NMs of hidrophobically modified polyacrylic acid (HM-PAA) to tadpoles of Epidalea calamita and Pelophylax perezi. For this, tadpoles of E. calamita and P. perezi were exposed to a range of six concentrations of HM-PAA plus a control...

Larval nematodes found in amphibians from northeastern Argentina

González,CE.; Hamann,MI.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2010 EN
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37.12%
Five species of amphibians, Leptodactylus podicipinus, Scinax acuminatus, S. nasicus, Rhinella fernandezae and Pseudis paradoxa, were collected in Corrientes province, Argentina and searched for larval nematodes. All larval nematodes were found as cysts in the serous of the stomach of hosts. Were identified one superfamily, Seuratoidea; one genus, Spiroxys (Superfamily Gnathostomatoidea) and one family, Rhabdochonidae (Superfamily Thelazioidea). We present a description and illustrations of these taxa. These nematodes have an indirect life cycle and amphibians are infected by consuming invertebrate, the intermediate hosts. The genus Spiroxys and superfamily Seuratoidea were reported for the first time for Argentinean amphibians.

Effect of season and temperature on mortality in amphibians due to chytridiomycosis

Berger, L.; Speare, R.; Hines, H.; Marantelli, G.; Hyatt, A.; McDonald, K.; Skerratt, L.; Olsen, V.; Clarke, J.; Gillespie, G.; Mahony, M.; Sheppard, N.; Williams, C.; Tyler, M.
Fonte: Australian Veterinary Assn Publicador: Australian Veterinary Assn
Tipo: Artigo de Revista Científica
Publicado em //2004 EN
Relevância na Pesquisa
37.25%
To investigate the distribution and incidence of chytridiomycosis in eastern Australian frogs and to examine the effects of temperature on this disease. A pathological survey and a transmission experiment were conducted. Diagnostic pathology examinations were performed on free‐living and captive, ill and dead amphibians collected opportunistically from eastern Australia between October 1993 and December 2000. We conducted a transmission experiment in the laboratory to investigate the effects of temperature: eight great barred frogs () exposed to zoospores of and six unexposed frogs were housed individually in each of three rooms held at 17°C, 23°C and 27°C. Chytridiomycosis was the cause of death or morbidity for 133 (55.2%) of 241 free‐living amphibians and for 66 (58.4%) of 113 captive amphibians. This disease occurred in 34 amphibian species, was widespread around the eastern seaboard of Australia and affected amphibians in a variety of habitats at high and low altitudes on or between the Great Dividing Range and the coast. The incidence of chytridiomycosis was higher in winter, with 53% of wild frogs from Queensland and New South Wales dying in July and August. Other diseases were much less common and were detected mostly in spring and summer. In experimental infections...

Host-defence peptides from the glandular secretions of amphibians: structure and activity

Pukala, T.; Bowie, J.; Maselli, V.; Musgrave, I.; Tyler, M.
Fonte: Royal Soc Chemistry Publicador: Royal Soc Chemistry
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
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This review covers the literature on the subject of biologically active peptides from the glands of amphibians. These include neuropeptides, antimicrobial and anticancer active peptides, antiviral agents, fungicides and peptides which complex with Ca²⁺ calmodulin. Other topics covered include sex pheromones from amphibians, and the use of peptide profiling to differentiate between species and different populations of the same species.; Tara L. Pukala, John H. Bowie, Vita M. Maselli, Ian F. Musgrave and Michael J. Tyler; Copyright © The Royal Society of Chemistry 2006 Reproduced by permission of The Royal Society of Chemistry

Effects of land-use change on community composition of tropical amphibians and reptiles in Sulawesi, Indonesia

Wanger, T.; Iskandar, D.; Motzke, I.; Brook, B.; Sodhi, N.; Clough, Y.; Tscharntke, T.
Fonte: Blackwell Publishing Inc Publicador: Blackwell Publishing Inc
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
37.12%
Little is known about the effects of anthropogenic land-use change on the amphibians and reptiles of the biodiverse tropical forests of Southeast Asia. We studied a land-use modification gradient stretching from primary forest, secondary forest, natural-shade cacao agroforest, planted-shade cacao agroforest to open areas in central Sulawesi, Indonesia. We determined species richness, abundance, turnover, and community composition in all habitat types and related these to environmental correlates, such as canopy heterogeneity and thickness of leaf litter. Amphibian species richness decreased systematically along the land-use modification gradient, but reptile richness and abundance peaked in natural-shade cacao agroforests. Species richness and abundance patterns across the disturbance gradient were best explained by canopy cover and leaf-litter thickness in amphibians and by canopy heterogeneity and cover in reptiles. Amphibians were more severely affected by forest disturbance in Sulawesi than reptiles. Heterogeneous canopy cover and thick leaf litter should be maintained in cacao plantations to facilitate the conservation value for both groups. For long-term and sustainable use of plantations, pruned shade trees should be permanently kept to allow rejuvenation of cacao and...

Biologically active peptides from Australian amphibians.

Jackway, Rebecca Jo
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2008
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37.03%
Amphibians secrete potent host defence compounds from dorsal glands onto the skin when stressed, sick or under attack by predators and microbials. Many of these defence compounds, such as biologically active peptides, provide potential targets for new biotechnological and therapeutic investigation. The research presented in this study focuses on the isolation and investigation of peptides from Australian frogs of the genera Litoria and Crinia and endeavours to determine the biological activity and important structural and mechanistic features of these biological compounds. Isolation and identification of the skin peptide profile of the Eastern Dwarf Tree Frog Litoria fallax has revealed a number of novel peptides named fallaxidins. This frog species is quite unique in that it does not secrete a peptide that displays potent broad spectrum antimicrobial activity nor a peptide that inhibits nitric oxide formation through the enzyme neuronal nitric oxide synthase. Instead it secretes several narrow spectrum antimicrobial peptides, including fallaxidin 3.1. In addition, there are numerous small peptides displaying unique primary structures with unknown biological function. Interestingly, L. fallax produces a skin peptide profile that is quite distinct from the skin peptide profiles of other related Litoria species. The majority of anurans from the Litoria genus contain at least one peptide in their skin secretion that inhibits the enzyme neuronal nitric oxide synthase. These peptides exert this action by preventing the association of the regulatory cofactor Ca²⁺ calmodulin to the enzyme binding site. The non-covalent binding of the potent neuronal nitric oxide synthase inhibitor dahlein 5.6 (L. dahlii) to calmodulin in the presence of Ca²⁺ is confirmed by electrospray ionisation mass spectrometry. A peptide-protein complex was observed in the gas-phase with a 1:1:4 calmodulin/dahlein 5.6/Ca²⁺ stoichiometry. In addition...

The energy cost of embryonic development in fishes and amphibians, with emphasis on new data from the Australian lungfish, Neoceratodus forsteri

Mueller, C.; Joss, J.; Seymour, R.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
Relevância na Pesquisa
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The rate of oxygen consumption throughout embryonic development is used to indirectly determine the ‘cost’ of development, which includes both differentiation and growth. This cost is affected by temperature and the duration of incubation in anamniote fish and amphibian embryos. The influences of temperature on embryonic development rate, respiration rate and energetics were investigated in the Australian lungfish, Neoceratodus forsteri, and compared with published data. Developmental stage and oxygen consumption rate were measured until hatching, upon which wet and dry gut-free masses were determined. A measure of the cost of development, the total oxygen required to produce 1 mg of embryonic dry tissue, increased as temperature decreased. The relationship between the oxygen cost of development (C, ml mg−1) and dry hatchling mass (M, mg) in fishes and amphibians is described by C = 0.30 M0.22 ± 0.13 (95% CI), r 2 = 0.52. The scaling exponent indicates that the cost of embryonic development increases disproportionally with increasing hatchling mass. At 15 and 20°C, N. forsteri cost of development is significantly lower than the regression mean for all species, and at 25°C is lower than the allometrically scaled data set. Unexpectedly...

Land-use change, tropical biodiversity, and ecosystem services - Southeast Asian amphibians and reptiles in focus.

Wanger, Thomas Cherico
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2011
Relevância na Pesquisa
37.29%
In the tropics, global food demand and population growth have already led to conversion of more than 50 % of formerly forested areas into agricultural landscapes. Across all tropical regions, Southeast Asia suffers from the highest deforestation rates, where land-use change is mainly driven by rapid expansion of biofuel and cash crops such as cacao. The ecological effects of agricultural expansion on biodiversity and ecosystem services are little known, in particular, in chronically understudied areas like Sulawesi (Indonesia), the third largest cacao producer globally. Moreover, certain taxonomic groups such as amphibians and reptiles remain particularly poorly studied, yet are the most threatened vertebrate groups on the planet. My thesis targets the impact of land-use change on Southeast Asian amphibian and reptile diversity as well as their ecosystem services provided. After an introduction to the research context, the first chapter shows how land use change from pristine forest to open areas impacts amphibians and reptiles. I use Bayesian modelling to examine environmental predictors of diversity patterns to then derive the first assessment of how amphibians and reptiles are affected by cacao farming in Sulawesi. In the second chapter...

Pheromones, attractants and other chemical cues of aquatic organisms and amphibians

Cummins, S.; Bowie, J.
Fonte: Royal Soc Chemistry Publicador: Royal Soc Chemistry
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
36.88%
This review covers the subject of pheromones, attractants and other chemical cues of aquatic invertebrates, fishes and amphibians (including salamanders and anurans). Major topics include the sex pheromones of gastropods, salamanders and a giant tree frog, and the conspecific attraction of sperm to ova of some of the organisms and animals described in this review.; Scott F. Cummins and John H. Bowie

A survey on the amphibians of Ambagamuwa, a tropical wet midland area in Sri Lanka

Nayana Pradeep Kumara, D.M.; Ukuwela, K.D.B.
Fonte: Societas Europaea Herpetologica Publicador: Societas Europaea Herpetologica
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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36.88%
A survey to assess the amphibian diversity of Ambagamuwa area in the mid-hills of Sri Lanka was carried out from January-February 2003 and in August 2007. Five different habitat types including gardens, primary forests, secondary forests, paddy fields and tea plantations were systematically sampled and investigated for amphibians. The survey revealed a total of 19 amphibian species with eleven of them endemic to the island and nine of them listed in the 2007 IUCN red list of threatened species. Two new frog species of the genus Philautus were discovered in this area. The overall existence of a high number of threatened species and the possible existence of so far undiscovered species strikes the importance of an urgent conservation of this area.; D.M. Nayana Pradeep Kumara & Kanishka D.B. Ukuwela

Effects of photoperiod and temperature on testicular function in amphibians

Paniagua, R.; Fraile, Benito; Sáez, F.J.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
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Most amphibians present an annual testicular cycle characterized by a quiescent period (late autumn-winter) and a spermatogenic period (spring and summer). At the end of the period of spermatogenesis undifferentiated interstitial cells transform into steroid-secreting Leydig cells which regress in spring at the beginning of the new spermatogenetic cycle. The testicular cycle is controlled by the pituitary gonadotropin levels which are high in autumn and winter, low in spring and increase temporarily in the middle of summer. Photoperiod and temperature seem to be the most important externa1 factors involved in the regulation of this cycle in many amphibian species since the colder the geographic area, the longer the quiescent period and the shorter the spermatogenic period. This suggests the occurrence of a potentially continuous cycle in these species, in contrast with that which occurs in other species having an endogenous rhythm of testicular function which is much less sensitive to environmental factors. Although the specific response to temperature can vary widely between species, the most frequent observation in amphibians with a potentiaiiy continuous cycle is that exposure to mild temperatures (15-20° C...

Biodiversity of trematodes associated with amphibians from a variety of habitats in Corrientes Province, Argentina

Hamann, Monika Ines; Kehr, Arturo Ignacio; Gonzalez, Cynthya Elizabeth
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: info:eu-repo/semantics/article; info:ar-repo/semantics/artículo; info:eu-repo/semantics/publishedVersion Formato: application/pdf
ENG
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The main goals of this study were to compare the richness of parasitic trematodes in amphibians with diverse habits (terrestrial, fossorial, semi-aquatic and arboreal), and to evaluate whether the composition of the trematode community is determined by ecological relationships. Specimens were collected between April 2001 and December 2006 from a common area (30 ha) in Corrientes Province, Argentina. Trematodes of amphibians in this area comprised a total of 19 species, and were dominated by common species. Larval trematodes presented highest species richness, with the metacercaria of Bursotrema tetracotyloides being dominant in the majority (78%) of the parasite communities. Adults of the trematode Catadiscus inopinatus were dominant in the majority (67%) of amphibians. The amphibians Leptodactylus latinasus, Leptodactylus bufonius and Scinax nasicus presented a high diversity of trematodes, whereas Leptodactylus chaquensis had the lowest diversity even though it presented with the highest species richness. The patterns of similarity among amphibian species showed groups linking with their habitats. Leptodactilid amphibians, with a generalist diet and an active foraging strategy showed highest infection rates with adult trematodes. The mean richness of trematode species related to host´s habitat preferences was higher in semi-aquatic amphibians. Results suggest that semi-aquatic amphibians...

A comparison of techniques for sampling amphibians in the forests of south-east Queensland, Australia

Parris, Kirstem M; Norton, Tony; Cunningham, Ross
Fonte: East Tennessee University Publicador: East Tennessee University
Tipo: Artigo de Revista Científica
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We employed three techniques for sampling amphibians (nocturnal stream searching, pitfall traps with drift fences, and automatic tape recording of anuran calls) concurrently for six nights at 20 forest sites in south-east Queensland, Australia, to compare their performance. Nocturnal stream searching was the most sensitive sampling technique, detecting the most species with the fewest nights of survey. Pitfall trapping was the least sensitive sampling technique. On average, a minimum of four nights of survey was required to detect the range of amphibian species present at a site. Nocturnal stream searches and automatic tape recorders were robust in the range of conditions encountered during the survey, with no significant relationships found between temporal or spatial variation in their performance and weather or site conditions. This systematic study represents one of few to compare different techniques for sampling amphibians in a given region, and the first such study to compare automatic tape recording of anuran calls with other, more traditional sampling techniques.

Diversity, natural history and conservation of amphibians and reptiles from the San Vito Region, southwestern Costa Rica

Santos-Barrera,Georgina; Pacheco,Jesus; Mendoza-Quijano,Fernando; Bolaños,Federico; Cháves,Gerardo; Daily,Gretchen C; Ehrlich,Paul R; Ceballos,Gerardo
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
Relevância na Pesquisa
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We present an inventory of the amphibians and reptiles of the San Vito de Coto Brus region, including the Las Cruces Biological Station, in southern Costa Rica, which is the result of a survey of the herpetofauna occurring in mountain forest fragments, pastures, coffee plantations, and other disturbed areas. We found 67 species, included 26 species of amphibians and of 41of reptiles. We describe the distribution patterns of the community on the basis of the life zones, elevation, fragmentation, and degree of anthropogenic impact. We also provide some nouvelle data on the systematics of some select taxa, their geographical ranges, microhabitats, activity, and other relevant ecological and natural history features. Finally, we comment on the present conservation status of the herpetofauna in the region. Previous literature and collection records indicate a higher number of species occurring in this area, which suggests that some declines have occurred, especially of amphibians, in last decades. Rev. Biol. Trop. 56 (2): 755-778. Epub 2008 June 30.

Amphibians and reptiles associated with the prairie dog grasslands ecosystem and surrounding areas at the Janos Casas Grandes complex, northwestern Chihuahua, Mexico

SANTOS-BARRERA,Georgina; PACHECO,Jesús; CEBALLOS,Gerardo
Fonte: Instituto de Ecología A.C. Publicador: Instituto de Ecología A.C.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
Relevância na Pesquisa
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Prairie dogs (Cynomys ludovicianus) are considered a keystone species that forms extensive colonies in the grasslands of western and central North America. These colonies are characterized by high diversity of associated vertebrates. The largest colonies in North America are located in the Janos region, northwestern Chihuahua, Mexico. In this study we present an inventory of the amphibians and reptiles inhabiting at prairie dog grasslands and surrounding mesquite scrublands in the Janos region. Methods to assess the herpetofauna included the use of a combined system of pitfall traps and visual encounter surveys (VES). We found 9 species of amphibians and 35 of reptiles. Of these species, 28 were closely related to prairie dog colonies, and 18 were exclusively recorded in this habitat. Additionally, 13 species were restricted to the mesquite scrubland. The Janos amphibian and reptile communities are of conservation concern, because 16 of the included species (1 amphibian and 15 reptiles) are considered at some risk of extinction. The diversity of amphibians and reptiles in the Janos region is clearly high in comparison with other grasslands. Our results strongly support the assumption that prairie dog grasslands are important for maintaining the mammal and avian diversity in the ecosystems of the Chihuahuan desert.