280 resultados para Lizards.
Resumo:
[EN] The Canary lsland lizards constitute a monophyletic group which separated from the rest of the family shortly after the first islands of the archipelago emerged. Five living and at least one recently extinct species belong to the genus Gallotia. In addition, two of the living species, Gallotia simonyi and Gallotia stehlini have become extinct on Gomera and Tenerife, respectively. Juveniles of all species present tricuspid teeth. This character is preserved in the adults with changes to one degree or another in G. galloti, G. caesaris, G. simonyi and G. goliath. In G. atlantica there are only two cuspids and G. stehlini has 4 or more.
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The aim of this study was to analyse seed dispersal and establishment of Solanum thomasiifolium in an area of nativo vegetation in Espirito Santo state on the southeastern Brazilian coast. Ten species of birds, the crab-eating fox (Cerdocyon thous), and one species of lizard (Tropidurus torquatus) fed on S. thomasiifolium fruits and dispersed viable seeds in their faeces. The proportional contribution of each of these groups to seed dispersal was 77% (birds), 19% (crab-eating fox) and 4% (lizards). Ants also contributed to seed dispersal. More seeds were deposited in vegetation islands than in the surrounding open areas. Germination rates of seeds collected directly from fruit (control), bird droppings, the faeces of crab-eating foxes and lizards were, respectively, 64, 64, 53, and 80 %. Differences among these rates were all significant, except between birds and control. Lizards were important as seed carriers between nearby islands and they expelled a higher proportion of viable seeds. Birds and the crab-eating foxes did not enhance seed germination, but promoted seed dispersal over a wider area. Plant architecture, fruit productivity, fruit characteristics and the diversity of frugivores are important for the success of S. thomasiifolium in habitat colonization.
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Os Cerrados sul-americanos abrigam alta diversidade de répteis, incluindo elevado número de endemismos. No entanto, o conhecimento desta diversidade é ainda incompleto frente à acelerada transformação das paisagens naturais no Brasil central. Constituem, portanto, uma das regiões prioritárias para estudo e conservação da biodiversidade mundial. Estudos intensivos sobre a fauna de répteis do Cerrado são necessários e urgentes para melhor compreensão dos processos que levaram à sua origem e distribuição e para subsidiar ações de conservação. Por meio de métodos padronizados, amostramos duas regiões ainda inexploradas da Estação Ecológica Serra Geral do Tocantins, situada na região do Jalapão. Registramos 45 espécies de répteis para a EESGT e entorno, o que representa uma riqueza alta e comparável à de outras regiões bem amostradas do Cerrado. Curvas de acumulação e estimadores indicam que a riqueza local de lagartos e anfisbenídeos aproxima-se da riqueza real enquanto a de serpentes é subestimada. A distribuição não-aleatória das espécies na paisagem concorda com evidências anteriores sugerindo utilização diferencial dos hábitats pelos répteis. Reunindo os resultados do presente estudo com os de levantamentos prévios realizados na região, registramos 88 espécies de répteis para o Jalapão sendo oito registros novos que incluem Bachia oxyrhina uma espécie recém descrita da região. As espécies da área apresentam três padrões gerais de distribuição: (1) espécies endêmicas do Cerrado, (2) espécies compartilhadas com domínios da diagonal de formações abertas sul-americanas, e (3) espécies de ampla ocorrência, compartilhadas também com ecossistemas florestais. Prevalecem espécies de ampla distribuição, porém é grande o número de espécies típicas do Cerrado, incluindo cinco possivelmente endêmicas do Jalapão, e há contribuição importante da fauna da Caatinga. A distribuição dos répteis em escala local e regional demonstra a necessidade de considerar a heterogeneidade paisagística para o planejamento de diretrizes visando à conservação em regiões do Cerrado. Por sua grande extensão, posição biogeográfica e complexidade de relevo e tipos de hábitat, a EESGT tem papel fundamental para a preservação e conhecimento da diversidade de répteis do Cerrado.
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O presente trabalho consiste em um inventário da herpetofauna do Parque Estadual Carlos Botelho (PECB), localizado na região da Serra de Paranapiacaba, Estado de São Paulo. Os dados foram obtidos por meio de coletas em seis áreas dentro do PECB durante um período de 76 dias distribuídos em um ano, e também por meio de consulta a coleções científicas para obtenção de dados secundários. São apresentados resultados sobre a biologia e ocorrência das espécies no PECB e no Brasil, além de fotografias das diferentes espécies que compõem a herpetofauna do PECB. A herpetofauna do PECB pode ser considerada uma das mais diversificadas de São Paulo, com 65 espécies de anfíbios confirmadas e 59 espécies de répteis registrados neste trabalho. Das 65 espécies de anfíbios, 84% (55 spp.) são endêmicas das formações florestais da Mata Atlântica. Devido às características do relevo do PECB, foram encontrados diferentes padrões altitudinais para os anfíbios: 46% das espécies foram registradas apenas em altitudes acima de 500 m, enquanto que 9% são exclusivas das regiões abaixo de 400 m e 45% ocorrem em todas as áreas amostradas do Parque. Das 59 espécies de répteis do PECB, foram registradas 10 espécies de lagartos, 48 de serpentes e um quelônio. Dentre as serpentes coletadas no PECB, a jararaca Bothrops jararaca foi a mais frequente, com 26,9% (N = 14) do total registrado. Espécies de difícil amostragem, como Echinanthera cephalostriata (13,5%; N = 7) e Taeniophallus affinis (7,7%; N = 4), também foram numerosas no PECB. Dentre os lagartos, Enyalius iheringii foi a espécie mais abundante, com 50% (N = 16) de registros. Uma análise de agrupamento entre 25 taxocenoses de anfíbios brasileiras, incluindo o PECB, resultou na formação de quatro agrupamentos principais. A anurofauna do PECB é mais relacionada com as taxocenoses do Parque Estadual Jacupiranga (0,68) e do Parque Estadual Intervales (0,66). Estes Parques se encontram geograficamente próximos e constituem um dos maiores fragmentos preservados de Mata Atlântica no Brasil. Este trabalho é o primeiro a apresentar a lista de répteis do PECB, alem de complementar o conhecimento em relação a fauna de anfíbios do PECB.
Resumo:
A ocorrência de Giardia, Cryptosporidium e microsporídios foi investigada por meio da análise de 98 amostras fecais de animais silvestres capturados em uma área de desmatamento para a construção das barragens de Paraitinga e Biritiba, localizadas nos Municípios de Mogi das Cruzes, Salesópolis e Biritiba-Mirim, no Estado de São Paulo. As amostras foram obtidas de 46 roedores, 21 marsupiais, 16 sapos, nove morcegos, três primatas e três lagartos. As técnicas de centrífugo-flutuação com sulfato de zinco, de Kinyoun e a coloração de Gram-Chromotrope foram utilizadas, respectivamente, para a pesquisa de Giardia, de Cryptosporidium e de microsporídios. O total de animais parasitados por um dos protozoários investigados foi de 17,35% (17/98). Cistos de Giardia foram encontrados em amostras fecais de dois pequenos roedores da espécie Coendou villosus (ouriço-cacheiro). Os três animais positivos para Cryptosporidium foram roedores das espécies Akodon montensis, Thaptomys nigrita (ambos conhecidos como ratos do mato) e Sciurus aestuans (serelepe ou caxinguelê). Esporos de microsporídios foram encontrados nas fezes de 12 animais, sendo seis roedores das espécies Oligoryzomys sp.(um), Akodon montensis (três) e Coendou villosus (dois), três marsupiais pertencentes às espécies Didelphis aurita (dois) e Marmosops incanus (um) e três morcegos da espécie Diphylla ecaudata. Este é o primeiro relato de microsporidiose em animais silvestres no Brasil. A presente investigação enfatiza a importância de animais silvestres, particularmente pequenos mamíferos, como potenciais fontes de infecção desses protozoários para outras populações animais, incluindo o homem, em áreas de desmatamento.
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Prince Maximilian zu Wied's great exploration of coastal Brazil in 1815-1817 resulted in important collections of reptiles, amphibians, birds, and mammals, many of which were new species later described by Wied himself The bulk of his collection was purchased for the American Museum of Natural History in 1869, although many ""type specimens"" had disappeared earlier. Wied carefully identified his localities but did not designate type specimens or type localities, which are taxonomic concepts that were not yet established. Information and manuscript names on a fraction (17 species) of his Brazilian reptiles and amphibians were transmitted by Wied to Prof. Heinrich Rudolf Schinz at the University of Zurich. Schinz included these species (credited to their discoverer ""Princ. Max."") in the second volume of Das Thierreich ... (1822). Most are junior objective synonyms of names published by Wied. However, six of the 17 names used by Schinz predate Wied's own publications. Three were manuscript names never published by Wied because he determined the species to be previously known. (1) Lacerta vittata Schinz, 1822 (a nomen oblitum) = Lacerta striata sensu Wied (a misidentification, non Linnaeus nec sensu Merrem) = Kentropyx calcarata Spix, 1825, herein qualified as a nomen protectum. (2) Polychrus virescens Schinz, 1822 = Lacerta marmorata Linnaeus, 1758 (now Polychrus marmoratus). (3) Scincus cyanurus Schinz, 1822 (a nomen oblitum) = Gymnophthalmus quadrilineatus sensu Wied (a misidentification, non Linnaeus nec sensu Merrem) = Micrablepharus maximiliani (Reinhardt and Lutken, ""1861"" [1862]), herein qualified as a nomen protectum. Qualifying Scincus cyanurus Schinz, 1822, as a nomen oblitum also removes the problem of homonymy with the later-named Pacific skink Scincus cyanurus Lesson (= Emoia cyanura). The remaining three names used by Schinz are senior objective synonyms that take priority over Wied's names. (4) Bufo cinctus Schinz, 1822, is senior to Bufo cinctus Wied, 1823; both, however, are junior synonyms of Bufo crucifer Wied, 1821 = Chaunus crucifer (Wied). (5) Agama picta Schinz, 1822, is senior to Agama picta Wied, 1823, requiring a change of authorship for this poorly known species, to be known as Enyalius pictus (Schinz). (6) Lacerta cyanomelas Schinz, 1822, predates Teius cyanomelas Wied, 1824 (1822-1831) both nomina oblita. Wied's illustration and description shows cyanomelas as apparently conspecific with the recently described but already well-known Cnemidophorus nativo Rocha et al., 1997, which is the valid name because of its qualification herein as a nomen protectum. The preceding specific name cyanomelas (as corrected in an errata section) is misspelled several ways in different copies of Schinz's original description (""cyanom las,"" ""cyanomlas,"" and cyanom""). Loosening, separation, and final loss of the last three letters of movable type in the printing chase probably accounts for the variant misspellings.
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We describe Riama crypta, new species, from the western slopes of the Cordillera Occidental, Ecuador. This taxon was formerly referred to as Riama hyposticta, a rare species described on the basis of an adult male from northern Ecuador and here recorded from southwestern Colombia. The new species differs principally from Riama hyposticta by an incomplete superciliary series, formed just by the anteriormost superciliary scale (superciliary series complete in R. hyposticta, formed by five or six scales), no nasoloreal suture [= loreal absent] (complete (= loreal present] in R. hyposticta), distinct dorsolateral stripes at least anteriorly (scattered brown spots dorsally without dorsolateral stripes in R. hyposticta), and ventral coloration composed of small cream or brown spots or longitudinal stripes (dark brown with conspicuous transverse white bars and spots). Additionally, we document the presence of distal filiform appendages on the hemipenial lobes of both species.
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Many natural populations exploiting a wide range of resources are actually composed of relatively specialized individuals. This interindividual variation is thought to be a consequence of the invasion of `empty` niches in depauperate communities, generally in temperate regions. If individual niches are constrained by functional trade-offs, the expansion of the population niche is only achieved by an increase in interindividual variation, consistent with the `niche variation hypothesis`. According to this hypothesis, we should not expect interindividual variation in species belonging to highly diverse, packed communities. In the present study, we measured the degree of interindividual diet variation in four species of frogs of the highly diverse Brazilian Cerrado, using both gut contents and delta(13)C stable isotopes. We found evidence of significant diet variation in the four species, indicating that this phenomenon is not restricted to depauperate communities in temperate regions. The lack of correlations between the frogs` morphology and diet indicate that trade-offs do not depend on the morphological characters measured here and are probably not biomechanical. The nature of the trade-offs remains unknown, but are likely to be cognitive or physiological. Finally, we found a positive correlation between the population niche width and the degree of diet variation, but a null model showed that this correlation can be generated by individuals sampling randomly from a common set of resources. Therefore, albeit consistent with, our results cannot be taken as evidence in favour of the niche variation hypothesis.
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Bright coloration and complex visual displays are frequent and well described in many lizard families. Reflectance spectrometry which extends into the ultraviolet (UV) allows measurement of such coloration independent of our visual system. We examined the role of colour in signalling and mate choice in the agamid lizard Ctenophorus ornatus. We found that throat reflectance strongly contrasted against the granite background of the lizards' habitat. The throat may act as a signal via the head-bobbing and push-up displays of C. ornatus. Dorsal coloration provided camouflage against the granite background, particularly in females. C. ornatus was sexually dichromatic for all traits examined including throat UV reflectance which is beyond human visual perception. Female throats were highly variable in spectral reflectance and males preferred females with higher throat chroma between 370 and 400 nm. However, female throat UV chroma is strongly correlated to both throat brightness and chest UV chroma and males may choose females on a combination of these colour variables. There was no evidence that female throat or chest coloration was an indicator of female quality. However, female brightness significantly predicted a female's laying date and, thus, may signal receptivity. One function of visual display in this species appears to be intersexual signalling, resulting in male choice of females.
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The cloacal complex of Crocodylus porosus is composed of three chambers (proctodaeum, urodaeum, and coprodaeum) separated by tight, muscular sphincters. The proctodaeum is proximal to the cloacal vent and houses the genitalia. The urodaeum is the largest chamber, is capable of storing large quantities of urine, and is lined with an epithelium with the capacity for transepithelial water and ion exchange. The coprodaeum, the most orad cloacal chamber, is a small, only marginally expandable chamber that has an epithelium composed almost entirely of mucus-secreting cells. The coprodaeum and lower intestine are reported to be the site(s) for urine modification in birds and bladderless lizards. A radiographic trace of urine storage in C. porosus kept for 2 months under hyperosmotic conditions showed no signs of retrograde movement of urine into the coprodaeum or rectum. Instead, urine was stored in the urodaeum of C. porosus. Examination of the mucosal surface of the urodaeum by SEM showed a plastic response to environmental salinity, with a possible increase in surface area in animals kept in hyperosmotic water compared with animals from fresh water. We propose the urodaeum as the primary site for postrenal modification of urine in C, porosus. (C) 2000 Wiley-Liss, Inc.
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Matrix population models, elasticity analysis and loop analysis can potentially provide powerful techniques for the analysis of life histories. Data from a capture-recapture study on a population of southern highland water skinks (Eulamprus tympanum) were used to construct a matrix population model. Errors in elasticities were calculated by using the parametric bootstrap technique. Elasticity and loop analyses were then conducted to identify the life history stages most important to fitness. The same techniques were used to investigate the relative importance of fast versus slow growth, and rapid versus delayed reproduction. Mature water skinks were long-lived, but there was high immature mortality. The most sensitive life history stage was the subadult stage. It is suggested that life history evolution in E. tympanum may be strongly affected by predation, particularly by birds. Because our population declined over the study, slow growth and delayed reproduction were the optimal life history strategies over this period. Although the techniques of evolutionary demography provide a powerful approach for the analysis of life histories, there are formidable logistical obstacles in gathering enough high-quality data for robust estimates of the critical parameters.
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Female choice has rarely been documented in reptiles. In this study we examined the variation, condition-dependence and female preference for a range of male morphological and colour traits in the agamid lizard, Ctenophorus ornatus. Colour traits were measured with reflectance spectrophotometry which allows the accurate quantification of colour traits independent of the human visual system. All the colour traits varied greatly in brightness but only the throat showed high variation in the spectral shape. For the morphological traits, chest patch size showed the highest amount of variation and was also condition-dependent. Males with a larger chest patch also had a patch which was a darker black. Female mate choice trials were conducted on male chest patch size and body size, which is the trait females have preferred in other lizard species. Females showed no preference, measured as spatial association, for larger males or males with bigger chest patches. In post-hoc tests females did not prefer males with brighter throats or darker chests, Our findings suggest that females show no spatial discrimination between males on the basis of a range of traits most expected to influence female choice.
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Understanding the role of multiple colour signals during sexual signalling is a central theme in animal communication. We quantified the role of multiple colour signals (including ultraviolet, UV), measures of body size and testosterone levels in settling disputes between male rivals in an elaborately ornamented, African lizard, played out in a large 'tournament' in the wild. The hue and brightness (total reflectance) of the UV throat in Augrabies flat lizards, Platysaurus broadleyi, as well as body size, were consistent and strong predictors of 'fighting ability'. Males with high fighting ability were larger and displayed a UV throat with low total reflectance. In contrast, males with low fighting ability were smaller and had violet throats with broader spectral reflectance curves (higher total reflectance). As fighting ability is associated with alternative reproductive tactics in this system (territorial versus floater), we also examined the role of colour signals in predicting male reproductive tactic. Territorial males had UV throats with higher chroma but had poorer body condition than floater males, probably because of the energetic costs of maintaining a territory. Although testosterone was not a significant predictor of fighting ability or reproductive tactic, it was correlated with the hue of the UV throat, suggesting that testosterone may impose some constraint on signal expression. Lastly, we show that within the context of the natural signalling environment, UV-reflective throats constitute a conspicuous, effective signal that male Augrabies flat lizards use to advertise their status honestly to rivals. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.