Mauricio Almeida-Gomes

Herpetofauna of an Atlantic rainforest area (Morro São João) in Rio de Janeiro State, Brazil

We studied the herpetofaunal community from the Atlantic forest of Morro São João, in Rio de Janeiro State, Brazil, and present data on species composition, richness, relative abundance and densities. We combined three sampling methods: plot sampling, visual encounter surveys and pit-fall traps. We recorded sixteen species of amphibians and nine of reptiles. The estimated densities (based on results of plot sampling) were 4.5 ind/100 m2 for amphibians and 0.8 ind/100 m2 for lizards, and the overall density (amphibians and lizards) was 5.3 ind/100 m2. For amphibians, Eleutherodactylus and Scinax were the most speciose genera with three species each, and Eleutherodactylus binotatus was the most abundant species (mean density of 3.0 frogs/100 m2). The reptile community of Morro São João was dominated by species of the families Gekkonidae and Gymnophtalmidae (Lacertilia) and Colubridae (Serpentes). The gymnophtalmid lizard Leposoma scincoides was the most abundant reptile species (mean density of 0.3 ind/100 m2). We compare densities obtained in our study data with those of other studied rainforest sites in various tropical regions of the world.

Diet and microhabitat use by two Hylodinae species (Anura, Cycloramphidae) living in sympatry and syntopy in a Brazilian Atlantic Rainforest area

We analyzed the diet and microhabitat use for two Hylodinae anurans (Cycloramphidae), Hylodes phyllodes Heyer & Cocroft, 1986 and Crossodactylus gaudichaudii Dumeril & Bibron, 1841, living in sympatry at an Atlantic Rainforest area of Ilha Grande, in southeastern Brazil. The two species live syntopically at some rocky streams. The two species differed strongly in microhabitat use. Hylodes phyllodes occurred mainly on rocks, whereas C. gaudichaudii was observed mostly on the water. Regarding diet, coleopterans, hymenopterans (ants), and larvae were the most important prey item consumed by both species. Data suggest that microhabitat use appears to be an important parameter differentiating these frogs with respect to general resource utilization.

Anurofauna of an Atlantic Rainforest fragment and its surroundings in Northern Rio de Janeiro State, Brazil

We carried out a study on the anurofaunal community from an Atlantic Forest fragment (Monte Verde mountains) and the surrounding area in Cambuci municipality, Rio de Janeiro State, Brazil, which constitutes one of the largest fragments remaining in the largely deforested landscape of the northern portion of the State. We combined three sampling methods: plot sampling, transects and pit-fall traps. We recorded twenty species of amphibians, of which only eleven were found within the forest fragment (and five of these also occurred in the surrounding matrix). Two of the species recorded in the present study (Crossodactylus sp. and Ischnocnema cf. parva) may represent undescribed taxa. Our records expand the distribution range of one species (Scinax trapicheiroi) to the north, and fill a geographic distribution gap for another one (Ischnocnema oea). The estimated overall density of frogs living in the leaf litter of the fragment (based on results of plot sampling) was 3.1 individuals/100 m², with Haddadus binotatus being the most abundant species (2.4 individuals/100 m²). Comparisons of our data with those of other studies suggest that anuran communities in forest fragments ca. 1,000 ha or smaller may be severely limited in their richness, and often include a large proportion of species tolerant to open areas, such as many hylids. Our results show the importance of increasing knowledge about the anurofaunal community of the northern portion of the State of Rio de Janeiro and preserve the forest remnants that still exist in the region.

Density and richness of leaf litter frogs (Amphibia: Anura) of an Atlantic Rainforest area in the Serra dos Órgãos, Rio de Janeiro State, Brazil

Data on species composition, richness, and density are presented for the leaf litter frog assemblage of an area of Atlantic Rainforest at the Serra dos Orgaos mountain range, in the state of Rio de Janeiro, southeastern Brazil. Three sampling methods were used: plot sampling, visual encounter surveys, and pitfall traps. The local assemblage of leaf litter frogs was composed of 16 species, with the direct-developing species, Euparkerella brasiliensis (Parker, 1926), being the most abundant. The estimated density of the local leaf litter frog assemblage based on plot sampling was 17.1 ind/100 m2 and the estimated overall leaf litter frog mass was 684.2 g/ha. The estimated density of leaf litter frogs at the present study is the highest currently reported for Atlantic Rainforest areas, which reinforces the idea of higher densities of leaf litter frogs in the Neotropical Region compared to the Old World tropics.

Underestimation of Extinction Threat to Stream-Dwelling Amphibians due to Lack of Consideration of Narrow Area of Occupancy

MAURICIO ALMEIDA-GOMES,‡ † MARIA LUCIA LORINI,∗ † CARLOS FREDERICO DUARTE ROCHA,† AND MARCUS VINICIUS VIEIRA‡ ∗Departamento de Ciencias Naturais, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil †Departamento de Ecologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil ‡Departamento de Ecologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil

Landscape connectivity may explain anuran species distribution in an Atlantic forest fragmented area

In this work we evaluated anuran species distribution in an Atlantic forest fragmented landscape, in the state of Rio de Janeiro, Brazil. Sampling was carried out in three continuous forest sites, 12 forest fragments, and five pasture areas (matrix). We recorded, by visual encounter surveys, 2,495 individuals from 50 amphibian species for all sampled areas. Considering the pooled data, higher richness occurs in continuous forest area. Additionally, more than a third of species that occurred in continuous forest area did not occur in fragments or in matrix. Both ordination analyses showed that continuous forest sites clustered together and matrix areas seemed to be separated from other areas. This ordination resulted from the existence of species occurring only in continuous forest, suggesting that these species may be sensitive to habitat fragmentation. Besides, matrix appears separated from other areas due to occurrence of frog species typical from disturbed environments, which are not recorded in continuous forest sites or in sampled fragments. By analyzing the effect of landscape metrics, we found that there was a tendency for fragments with lower isolation to have higher species richness and proportion of species which did not occur in matrix areas and amphibian local communities seems to be affected in a more local scale by habitat changes. Because local matrix is apparently hostile to typically forest-associated amphibian species, many of them may be unable to reach most isolated fragments by dispersal, which may explain observed results.

The use of native vegetation as a proxy for habitat may overestimate habitat availability in fragmented landscapes

ContextNative vegetation is often used as a proxy for habitat to estimate habitat availability in landscapes. This approach may lead to incorrect estimates of the impacts of habitat loss and fragmentation on species, which have not been thoroughly quantified so far.ObjectivesWe quantified to what extent the loss of native vegetation reflect actual habitat loss by native species in landscapes. We tested the hypothesis that habitat availability declines at greater rates than native vegetation and thus is overestimated when it is quantified on the basis of native vegetation.MethodsUsing simulations, we quantified how the loss of native vegetation in artificial and real landscapes affects habitat availability for species with different habitat requirements. We contrasted a generalist species, which uses all native vegetation, with 10 habitat-specialist species classified into three categories (interior, patchy and riparian species).ResultsHabitat availability generally declined at greater rates than native vegetation for all specialist species. This pattern was apparent for different specialist species in a broad range of landscape types. Interior species always lost habitat availability more rapidly than the generalist species. Most riparian species lost habitat availability more rapidly than the generalist species. Responses of patchy species were more complex, depending on their dispersal abilities and landscape structure.ConclusionsHabitat availability is likely to be overestimated when native vegetation is used as proxy for habitat, because habitat availability will generally decline at greater rates than native vegetation. Therefore, a species-centered approach should be adopted when estimating habitat availability in landscapes.

Diet and nematode infection in Proceratoprhys boiei (Anura: Cycloramphidae) from two Atlantic rainforest remnants in Southeastern Brazil

Proceratophrys boiei is an endemic cycloramphid anuran inhabiting the leaf litter of Atlantic rainforests in Southeastern Brazil. We analyzed the whole digestive tract of 38 individuals of Proceratophrys boiei collected in two Atlantic Rainforest areas in the state of Rio de Janeiro, Brazil, to study the diet composition and the helminth fauna associated with this species. The main food items in P. boiei’s diet were Coleoptera, Orthoptera and Blattaria. Five nematode species were found: Aplectana delirae, Cosmocerca parva, Oxyascaris oxyascaris, Physaloptera sp. (larval stage only) and an unidentified nematode. Overall prevalence was 71% and mean infection intensity was 7.3 ± 5.8 nematodes per individual.

Diet of the lizard Ecpleopus gaudichaudii (Gymnophthalmidae) in Atlantic Rainforest, state of Rio de Janeiro, Brazil

In this study we analyzed the diet of the gymnophthalmid lizard Ecpleopus gaudichaudii Dumeril & Bibron, 1839, a typical inhabitant of the forest-floor leaf litter, in an Atlantic Forest area in the state of Rio de Janeiro, southeast- ern Brazil. The 26 individuals sampled during the study had a mean snout-vent length (SVL) of 36.2 ± 4.2 mm and a mean jaw width (JW) of 4.1 ± 0.5 mm. We did not find differences in SVL between males and females, though the sexes differed in JW when the effect of body size was factored out, with females presenting higher values. The diet of the lizards was composed exclusively of arthropods, especially isopods and orthopterans. The similarity in trophic niches among seasons (volumetric and numerical proportions of prey categories consumed) were 0.096 and to 0.43, respec- tively. There were also no detectable seasonal differences in mean number and mean volume of prey ingested, as well as no significant influence of lizard SVL on prey number and of lizard JW on mean prey volume, which may reflect the tendency of E. gaudichaudii to feed on few, relatively large prey.

Diversity and Distribution of Lizards in Fragmented Atlantic Forest Landscape in Southeastern Brazil

Abstract In this study, we evaluated how different lizard species were distributed in a fragmented Atlantic Forest landscape and the influence of landscape metrics on lizard species richness in sampled fragments. We sampled (between July 2007 and March 2010) three continuous forest sites of the Reserva Ecológica de Guapiaçu (REGUA), 12 forest fragments of different sizes and five pasture matrix areas. We recorded 8 lizard species, the most abundant being Ecpleopus gaudichaudii and Enyalius brasiliensis. Species richness in the continuous forest sites (N = 4) was lower than in the set of fragments (N = 8); fragments harbored both typical forest species and more generalist species. The forest areas differed in the composition of lizard species, with continuous forest sites having a composition similar to each other and to larger fragments, whereas the smaller fragments differed from the larger fragments but showed similarity to each other. These data indicated that fragment size (area) can be an important factor for the maintenance of lizard species diversity in fragmented Atlantic Forest landscapes. Resumo Neste estudo avaliamos como as diferentes espécies de lagartos estavam distribuídas em uma paisagem fragmentada de Mata Atlântica e a influência das métricas da paisagem sobre a riqueza de espécies de lagartos nos fragmentos amostrados. Amostramos (entre julho de 2007 e março de 2010) três localidades de floresta contínua da Reserva Ecológica de Guapiaçu (REGUA), 12 fragmentos florestais de diferentes tamanhos e cinco áreas de matriz de pasto. No total, registramos 8 espécies de lagartos e as mais abundantes foram Ecpleopus gaudichaudii e Enyalius brasiliensis. A riqueza de espécies encontrada nos sítios de floresta continua (N = 4) foi menor do que a encontrada no conjunto de fragmentos (N = 8), o que pode ser explicado pelo conjunto de fragmentos abrigarem tanto espécies típicas de hábitats florestais quanto espécies mais generalistas. As áreas de floresta diferiram em relação à composição de espécies, com os sítios de floresta contínua tendo uma composição similar entre si e com os maiores fragmentos, enquanto que os menores fragmentos mostraram maior similaridade entre si. Esses dados indicam que o tamanho do fragmento (área) pode ser um importante fator para a manutenção da diversidade de espécies de lagartos em paisagens fragmentadas de Mata Atlântica.