Lizard assemblage from a sand dune habitat from southeastern Brazil: a niche overlap analysis.

Communities are structured by interactions of historical and ecological factors, which influence the use of different resources in time and space. We acquired data on time of activity, microhabitat use and diet of a lizard assemblage from a sand dune habitat in a coastal area, southeastern Brazil (Restinga de Jurubatiba). We analyzed the data of niche overlap among species in these three axes (temporal, spatial and trophic) using null models. We found a significant overlap within the trophic niche, whereas the overlap for the other axes did not differ from the expected. Based on this result, we discuss the factors acting on the structure of the local lizard community.

Feeding habits of the leaf litter frog Haddadus binotatus (Anura, Craugastoridae) from two Atlantic Forest areas in southeastern Brazil.

Haddadus binotatus is an endemic anuran of the Brazilian Atlantic Forest and currently, there is no information about the diet of this species. We analyzed the diet of two populations of this anuran in two states in southeast Brazil. Samplings were carried out in 2004 in the state of Rio de Janeiro and in 2009 and 2010 in the state of Espírito Santo. Haddadus binotatus presented a rich diet composition, preying 19 prey types. Orthoptera, Coleoptera, and Blattodea were the most important preys in the Rio de Janeiro population, and Orthoptera, Araneae and Hemiptera were the most important in the Espírito Santo population. The diet composition differed numerically between the two localities, but not in terms of volume, which can reflect local differences in the prey availability in the two habitats. The jaw width limited the size of prey, which is expected for predators who swallow the preys without chewing. The proportion of individuals with empty stomachs was higher in the Rio de Janeiro population (39.2%) than in the Espírito Santo population (17.9%), suggesting that the former could be in a lower energy balance. The females of the species were larger than the males, which may result from the production of larger eggs.

Feeding habits, microhabitat use, and daily activity of Cycloramphus brasiliensis (Anura: Cycloramphidae) from the Atlantic Rainforest, Brazil

We analyzed the feeding habits, microhabitat use, and daily activity period of the anuran species Cycloramphus brasiliensis (Steindachner, 1864), endemic to the Atlantic Rainforest biome. The only previous studies on this species focused on the systematics and new altitudinal records. This study was conducted in a large forest remnant located in the municipalities of Guapimirim and Cachoeiras de Macacu. We captured frogs through visual encounter surveys and recorded the frequency of microhabitat types used by them, and the time of capture. Diet was analyzed in terms of number, volume and frequency of occurrence of items. Individuals of C. brasiliensis occurred in association with fast-moving rocky portions of clear freshwater rivers, indicating a rheophilic habit, and were active mainly at night. Such as most anuran species, the diet of Cycloramphus brasiliensis was mainly based on arthropods, and included Blattodea, Formicidae, and Coleoptera as most important prey items.

Feeding habits, microhabitat use, and daily activity of Cycloramphus brasiliensis (Anura: Cycloramphidae) from the Atlantic Rainforest, Brazil

We analyzed the feeding habits, microhabitat use, and daily activity period of the anuran species Cycloramphus brasiliensis (Steindachner, 1864), endemic to the Atlantic Rainforest biome. The only previous studies on this species focused on the systematics and new altitudinal records. This study was conducted in a large forest remnant located in the municipalities of Guapimirim and Cachoeiras de Macacu. We captured frogs through visual encounter surveys and recorded the frequency of microhabitat types used by them, and the time of capture. Diet was analyzed in terms of number, volume and frequency of occurrence of items. Individuals of C. brasiliensis occurred in association with fast-moving rocky portions of clear freshwater rivers, indicating a rheophilic habit, and were active mainly at night. Such as most anuran species, the diet of Cycloramphus brasiliensis was mainly based on arthropods, and included Blattodea, Formicidae, and Coleoptera as most important prey items.

Feeding habits, microhabitat use, and daily activity of Cycloramphus brasiliensis (Anura: Cycloramphidae) from the Atlantic Rainforest, Brazil

We analyzed the feeding habits, microhabitat use, and daily activity period of the anuran species Cycloramphus brasiliensis (Steindachner, 1864), endemic to the Atlantic Rainforest biome. The only previous studies on this species focused on the systematics and new altitudinal records. This study was conducted in a large forest remnant located in the municipalities of Guapimirim and Cachoeiras de Macacu. We captured frogs through visual encounter surveys and recorded the frequency of microhabitat types used by them, and the time of capture. Diet was analyzed in terms of number, volume and frequency of occurrence of items. Individuals of C. brasiliensis occurred in association with fast-moving rocky portions of clear freshwater rivers, indicating a rheophilic habit, and were active mainly at night. Such as most anuran species, the diet of Cycloramphus brasiliensis was mainly based on arthropods, and included Blattodea, Formicidae, and Coleoptera as most important prey items.

Species composition and density estimates of the anurofauna of a site within the northernmost large Atlantic Forest remnant (Parque Estadual do Desengano) in the state of Rio de Janeiro, Brazil / Composição de espécies e estimativa de densidade da anurofauna em uma área dentro do mais setentrional dos grandes remanescentes de Mata Atlântica (Parque Estadual do Desengano) do Estado do Rio de Janeiro, Brasil

We present data on species composition, relative abundance and estimated densities for leaf-litter anuran amphibians from an Atlantic Forest area within the Parque Estadual do Desengano, in the state of Rio de Janeiro, Brazil, based on results of a short-term survey carried out during the winter at altitudes of 1000-1500 m. Three sampling methods were used: plot sampling, visual encounter surveys (VES; performed during the day, at the twilight, and at night), and pitfall traps. We recorded 13 species, with the direct-developer Ischnocnema parva (Girard, 1853) being the most abundant. Most frogs (ca. 90% of all individuals) sampled by VES were captured during the crepuscular and nocturnal periods. The estimated density of the local leaf-litter frog assemblage based on plot sampling was 13.2 ind.100 m-2, which is one of the highest values currently reported for Atlantic Rainforest areas. This is the first study analyzing the anuran fauna of the Parque Estadual do Desengano and adds to the knowledge of the fauna of the northern region of the state of Rio de Janeiro, which is still poorly studied.

Apresentamos dados sobre a composição de espécies, abundância relativa e densidade estimada para anfíbios anuros de serrapilheira de uma área de Mata Atlântica no Parque Estadual do Desengano, no Estado do Rio de Janeiro, Brasil, com base em resultados de um estudo de curto prazo realizado durante o inverno a altitudes de 1000-1500 m. Três métodos de amostragem foram utilizados: amostragem em parcelas, encontros visuais (realizados durante o dia, no crepúsculo e à noite) e armadilhas de queda. Foram registradas 13 espécies, com Ischnocnema parva (Girard, 1853), uma forma com desenvolvimento direto, sendo a mais abundante. A maioria dos anuros (ca. 90% de todos os indivíduos) amostrados pelo método de encontros visuais foi coletada durante os períodos crepuscular e noturno. A densidade estimada para anuros de serrapilheira foi de 13,2 ind.100 m-2, que é um dos valores mais altos atualmente registrados para áreas de Mata Atlântica. Este é o primeiro estudo que analisa a fauna de anuros do Parque Estadual do Desengano e contribui para o conhecimento da fauna da região norte do estado do Rio de Janeiro, que ainda é pouco estudada.

Living in a caatinga-rocky field transitional habitat: ecological aspects of the whiptail lizard Cnemidophorus ocellifer (Teiidae) in northeastern Brazil

The ecology of the active forager lizard Cnemidophorus ocellifer (Spix, 1825) was studied to analyze food habits, thermal ecology and habitat use, in the Morro do Chapéu municipality (11º29'S, 41º07'W), state of Bahia, Brazil. Lizards (N = 34) were collected with rubber bands or with an air rifle and, for each individual, we recorded cloacal temperature (Tc), air temperature (Ta) (1 cm above the substrate) and substrate temperature (Ts) (to nearest 0.2ºC). We registered the microhabitat used by each animal at the moment of first sight and measured its morphological variables (nearest 0.1 mm). In the laboratory, we registered the number of items of each prey category to the taxonomic level of Order, its dimensions and frequencies. Data showed that, numerically, the category most consumed was Isoptera (84.4%). Volumetrically, the diet was composed predominantly by Orthoptera (27.5%) and Isoptera (21.5%). Prey items that occur aggregated in the environment (termites) were important in the diet of C. ocellifer, a characteristic of active foragers. Males and females did not differ in the types of prey consumed. Cnemidophorus ocellifer had a mean Tc in activity of 37.6 ± 1.6ºC and the relationship between Tc and ambient temperatures (Ts and Ta) was positive and significant (F2,28 = 4.814; R² = 0.256; p 0.05). Most lizards were first sighted on leaf litter inside shrubs (45.5%) and on leaf litter at shrub edge (42.4%). Cnemidophorus ocellifer had a relatively high mean Tc during activity, with Ts explaining most of the variation in lizard Tc.

Clutch size in the small-sized lizard Eurolophosaurus nanuzae (Tropiduridae): does it vary along the geographic distribution of the species?

We studied life history traits of females of the lizard Eurolophosaurus nanuzae (Rodrigues, 1981), an endemic species of rock outcrop habitats in southeastern Brazil. During October 2002 and 2003 we sampled three populations in sites that encompass the meridional portion of the geographic range of the species. Clutch size varied from one to three eggs, with most females carrying two eggs. Clutch size did not vary among populations, but was correlated to female body size. Only larger females produced clutches of three eggs. Females of the small-sized E. nanuzae produce eggs as large as those of medium-sized tropidurids, thus investing a considerable amount of energy to produce clutches resulting in high values of relative clutch mass.

No presente trabalho estudamos alguns aspectos da história de vida de fêmeas de Eurolophosaurus nanuzae (Rodrigues, 1981), endêmica dos campos rupestres da cadeia do Espinhaço, sudeste do Brasil. Durante outubro de 2002 e outubro de 2003 amostramos três populações em áreas cuja disposição geográfica engloba a parte meridional da distribuição da espécie. O tamanho da postura variou de um a três ovos, sendo que a maioria das fêmeas produziu uma ninhada de dois ovos. O número de ovos não variou entre as populações mas foi relacionado ao tamanho corporal das fêmeas (apenas as fêmeas maiores produziram uma postura de três ovos). As fêmeas de E. nanuzae produzem ovos de volume equiparável a espécies de médio tamanho corporal, resultando em elevados valores de massa relativa de postura.

Clutch size in the small-sized lizard Eurolophosaurus nanuzae (Tropiduridae): does it vary along the geographic distribution of the species?

We studied life history traits of females of the lizard Eurolophosaurus nanuzae (Rodrigues, 1981), an endemic species of rock outcrop habitats in southeastern Brazil. During October 2002 and 2003 we sampled three populations in sites that encompass the meridional portion of the geographic range of the species. Clutch size varied from one to three eggs, with most females carrying two eggs. Clutch size did not vary among populations, but was correlated to female body size. Only larger females produced clutches of three eggs. Females of the small-sized E. nanuzae produce eggs as large as those of medium-sized tropidurids, thus investing a considerable amount of energy to produce clutches resulting in high values of relative clutch mass.

No presente trabalho estudamos alguns aspectos da história de vida de fêmeas de Eurolophosaurus nanuzae (Rodrigues, 1981), endêmica dos campos rupestres da cadeia do Espinhaço, sudeste do Brasil. Durante outubro de 2002 e outubro de 2003 amostramos três populações em áreas cuja disposição geográfica engloba a parte meridional da distribuição da espécie. O tamanho da postura variou de um a três ovos, sendo que a maioria das fêmeas produziu uma ninhada de dois ovos. O número de ovos não variou entre as populações mas foi relacionado ao tamanho corporal das fêmeas (apenas as fêmeas maiores produziram uma postura de três ovos). As fêmeas de E. nanuzae produzem ovos de volume equiparável a espécies de médio tamanho corporal, resultando em elevados valores de massa relativa de postura.

Living in a caatinga-rocky field transitional habitat: ecological aspects of the whiptail lizard Cnemidophorus ocellifer (Teiidae) in northeastern Brazil

The ecology of the active forager lizard Cnemidophorus ocellifer (Spix, 1825) was studied to analyze food habits, thermal ecology and habitat use, in the Morro do Chapéu municipality (11º29'S, 41º07'W), state of Bahia, Brazil. Lizards (N = 34) were collected with rubber bands or with an air rifle and, for each individual, we recorded cloacal temperature (Tc), air temperature (Ta) (1 cm above the substrate) and substrate temperature (Ts) (to nearest 0.2ºC). We registered the microhabitat used by each animal at the moment of first sight and measured its morphological variables (nearest 0.1 mm). In the laboratory, we registered the number of items of each prey category to the taxonomic level of Order, its dimensions and frequencies. Data showed that, numerically, the category most consumed was Isoptera (84.4%). Volumetrically, the diet was composed predominantly by Orthoptera (27.5%) and Isoptera (21.5%). Prey items that occur aggregated in the environment (termites) were important in the diet of C. ocellifer, a characteristic of active foragers. Males and females did not differ in the types of prey consumed. Cnemidophorus ocellifer had a mean Tc in activity of 37.6 ± 1.6ºC and the relationship between Tc and ambient temperatures (Ts and Ta) was positive and significant (F2,28 = 4.814; R² = 0.256; p 0.05). Most lizards were first sighted on leaf litter inside shrubs (45.5%) and on leaf litter at shrub edge (42.4%). Cnemidophorus ocellifer had a relatively high mean Tc during activity, with Ts explaining most of the variation in lizard Tc.

Living in a caatinga-rocky field transitional habitat: ecological aspects of the whiptail lizard Cnemidophorus ocellifer (Teiidae) in northeastern Brazil

The ecology of the active forager lizard Cnemidophorus ocellifer (Spix, 1825) was studied to analyze food habits, thermal ecology and habitat use, in the Morro do Chapéu municipality (11º29'S, 41º07'W), state of Bahia, Brazil. Lizards (N = 34) were collected with rubber bands or with an air rifle and, for each individual, we recorded cloacal temperature (Tc), air temperature (Ta) (1 cm above the substrate) and substrate temperature (Ts) (to nearest 0.2ºC). We registered the microhabitat used by each animal at the moment of first sight and measured its morphological variables (nearest 0.1 mm). In the laboratory, we registered the number of items of each prey category to the taxonomic level of Order, its dimensions and frequencies. Data showed that, numerically, the category most consumed was Isoptera (84.4%). Volumetrically, the diet was composed predominantly by Orthoptera (27.5%) and Isoptera (21.5%). Prey items that occur aggregated in the environment (termites) were important in the diet of C. ocellifer, a characteristic of active foragers. Males and females did not differ in the types of prey consumed. Cnemidophorus ocellifer had a mean Tc in activity of 37.6 ± 1.6ºC and the relationship between Tc and ambient temperatures (Ts and Ta) was positive and significant (F2,28 = 4.814; R² = 0.256; p 0.05). Most lizards were first sighted on leaf litter inside shrubs (45.5%) and on leaf litter at shrub edge (42.4%). Cnemidophorus ocellifer had a relatively high mean Tc during activity, with Ts explaining most of the variation in lizard Tc.

Ecology of Ischnocnema parva (Anura: Brachycephalidae) at the Atlantic Rainforest of Serra da Concórdia, state of Rio de Janeiro, Brazil

Ischnocnema (Brachycephalidae) includes many species that are important members of the leaf litter frog communities in the Atlantic Rainforest of Brazil. Ischnocnema parva (Girard, 1853) is endemic to the Atlantic Rainforest biome and is restricted to the forests of southeastern Brazil. Currently, the available information about the ecology of I. parva is scarce. We studied the diet, the habitat use, reproduction and density of I. parva in an area of Atlantic Rainforest at the Concórdia mountain range, Rio de Janeiro. Individuals of I. parva were captured in April 2005 using different sampling methods: time constrained search (transects), plots of 5 x 5 m (25 m²) on the litter, and pitfall traps with drift fences. We found 240 frogs; 35 females and 205 males. Females (mean SVL = 19.1 mm) were significantly larger (F1,238 = 143.016, R² = 0.375, p 0.001) than males (13.2 mm). The species preyed mainly on arthropods, with ants and isopods being the most important items, both showing high values of importance index (Ix = 50.0 and 26.7, respectively). Ischnocnema parva is a terrestrial species whose preferential microhabitat at the Serra da Concórdia was the litter of the forest floor (78.7%). The activity was predominantly crepuscular-nocturnal and the estimated density of I. parva was 24.9 ind/100 m². For the eight ovigerous females captured, the mean number of mature oocytes per female was 25 (range: 22-30) and the oocyte mean diameter was 1.11 mm (N = 40 oocytes). Oocyte number increased with female body size (R² = 0.504, F1,6 = 6.107, p 0.05, N = 8), indicating that as females increase in size they produce larger clutches. Some ecological aspects such as diet and microhabitat use were similar to that observed for an insular population of I. parva, whereas reproductive traits differed. Thus, long term studies are necessary to understand the extent to which these differences are explained by environmental factors.

Ecology of Ischnocnema parva (Anura: Brachycephalidae) at the Atlantic Rainforest of Serra da Concórdia, state of Rio de Janeiro, Brazil

Ischnocnema (Brachycephalidae) includes many species that are important members of the leaf litter frog communities in the Atlantic Rainforest of Brazil. Ischnocnema parva (Girard, 1853) is endemic to the Atlantic Rainforest biome and is restricted to the forests of southeastern Brazil. Currently, the available information about the ecology of I. parva is scarce. We studied the diet, the habitat use, reproduction and density of I. parva in an area of Atlantic Rainforest at the Concórdia mountain range, Rio de Janeiro. Individuals of I. parva were captured in April 2005 using different sampling methods: time constrained search (transects), plots of 5 x 5 m (25 m²) on the litter, and pitfall traps with drift fences. We found 240 frogs; 35 females and 205 males. Females (mean SVL = 19.1 mm) were significantly larger (F1,238 = 143.016, R² = 0.375, p 0.001) than males (13.2 mm). The species preyed mainly on arthropods, with ants and isopods being the most important items, both showing high values of importance index (Ix = 50.0 and 26.7, respectively). Ischnocnema parva is a terrestrial species whose preferential microhabitat at the Serra da Concórdia was the litter of the forest floor (78.7%). The activity was predominantly crepuscular-nocturnal and the estimated density of I. parva was 24.9 ind/100 m². For the eight ovigerous females captured, the mean number of mature oocytes per female was 25 (range: 22-30) and the oocyte mean diameter was 1.11 mm (N = 40 oocytes). Oocyte number increased with female body size (R² = 0.504, F1,6 = 6.107, p 0.05, N = 8), indicating that as females increase in size they produce larger clutches. Some ecological aspects such as diet and microhabitat use were similar to that observed for an insular population of I. parva, whereas reproductive traits differed. Thus, long term studies are necessary to understand the extent to which these differences are explained by environmental factors.

Ecology of Ischnocnema parva (Anura: Brachycephalidae) at the Atlantic Rainforest of Serra da Concórdia, state of Rio de Janeiro, Brazil

Ischnocnema (Brachycephalidae) includes many species that are important members of the leaf litter frog communities in the Atlantic Rainforest of Brazil. Ischnocnema parva (Girard, 1853) is endemic to the Atlantic Rainforest biome and is restricted to the forests of southeastern Brazil. Currently, the available information about the ecology of I. parva is scarce. We studied the diet, the habitat use, reproduction and density of I. parva in an area of Atlantic Rainforest at the Concórdia mountain range, Rio de Janeiro. Individuals of I. parva were captured in April 2005 using different sampling methods: time constrained search (transects), plots of 5 x 5 m (25 m²) on the litter, and pitfall traps with drift fences. We found 240 frogs; 35 females and 205 males. Females (mean SVL = 19.1 mm) were significantly larger (F1,238 = 143.016, R² = 0.375, p 0.001) than males (13.2 mm). The species preyed mainly on arthropods, with ants and isopods being the most important items, both showing high values of importance index (Ix = 50.0 and 26.7, respectively). Ischnocnema parva is a terrestrial species whose preferential microhabitat at the Serra da Concórdia was the litter of the forest floor (78.7%). The activity was predominantly crepuscular-nocturnal and the estimated density of I. parva was 24.9 ind/100 m². For the eight ovigerous females captured, the mean number of mature oocytes per female was 25 (range: 22-30) and the oocyte mean diameter was 1.11 mm (N = 40 oocytes). Oocyte number increased with female body size (R² = 0.504, F1,6 = 6.107, p 0.05, N = 8), indicating that as females increase in size they produce larger clutches. Some ecological aspects such as diet and microhabitat use were similar to that observed for an insular population of I. parva, whereas reproductive traits differed. Thus, long term studies are necessary to understand the extent to which these differences are explained by environmental factors.

How does chytrid infection vary among habitats? The case of Litoria wilcoxii (Anura, Hylidae) in SE Queensland, Australia.

Most analyses dealing with the geographical distribution of the chytrid fungus (Batrachochytrium dendrobatidis) have been performed on large geographical scales and data on more localized distribution of the chytrid within catchments are scarce. In this study, we compare the prevalence and intensity of infection of chytrid within and outside rainforest habitats at five independent catchments in southeast Queensland. In each catchment, we sampled adult Litoria wilcoxii along two transects on the same stream: one in forested areas, and the other in open nearby farmland. We analyzed swabs using quantitative PCR techniques. Male frogs were in higher densities in open habitats compared with the nearby forested areas. Infected male frogs were found in all catchments surveyed; however, prevalence of B. dendrobatidis in adult males was higher in the forested habitats than in the open habitats in four of the catchments. There was no significant difference in intensity of infection between forested and open habitats. For adult females and juveniles, sample sizes were not high enough for comparisons. Our results suggest that habitat influences chytrid prevalence and open areas may provide refuge from chytrid-induced population declines.

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 Órgãos 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.

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 Órgãos 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.

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.

Estudamos a comunidade herpetofaunística da Mata Atlântica do Morro São João, Estado do Rio de Janeiro, Brasil, e apresentamos dados da composição, riqueza, abundância relativa e densidade das espécies. Combinamos três metodologias de amostragem: parcelas, encontros visuais e armadilhas de queda. Registramos 16 espécies de anfíbios e 9 espécies de répteis. As densidades estimadas (baseadas nos resultados da amostragem através de parcelas) foram 4.5 ind/100 m² para anfíbios, 0.8 ind/100 m² para lagartos, e a densidade total (anfíbios e répteis) foi 5.3 ind/100 m². Para anfíbios, Eleutherodactylus e Scinax foram os gêneros com maior número de espécies, com três espécies cada, e Eleutherodactylus binotatus foi a espécie mais abundante (densidade média de 3.0 anuros/100 m²). A comunidade de répteis do Morro São João foi dominada por espécies da família Gekkonidae e Gymnophtalmidae (Lacertilia) e Colubridae (Serpentes). O lagarto gimnoftalmídeo Leposoma scincoides foi a espécie de réptil mais abundante (densidade média de 0.3 ind/100 m). Comparamos os dados de densidade obtidos no nosso estudo com os de outros estudos em florestas de várias regiões tropicais do mundo.

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.

The effect of hummingbird flower mites on nectar availability of two sympatric Heliconia species in a Brazilian Atlantic forest.

BACKGROUND AND AIMS: Hummingbird flower mites feed and reproduce in flowers of host plants pollinated by hummingbirds, and use the nostrils and bill of the hummingbird to move from plant to plant. These mites compete with the pollinator for the nectar produced by flowers. An investigation was made of the relationship between the pattern of nectar production and the effects of hummingbird flower mites in the flowers of two sympatric species of Heliconia (Heliconiaceae). METHODS: Nectar production was sampled by carrying out two experiments: 2-hour intervals and accumulated nectar. Flowers with and without mites were used in both experiments. KEY RESULTS: Exclusion of mites increased nectar production, especially in accumulated daily production (a maximum of 49 % more nectar). Both Heliconia species had the same pattern of nectar production: a high concentration in the morning, which was progressively reduced as the day passed. This pattern of nectar production coincides with the behaviour of the pollinator, which makes more frequent visits in the morning, as observed in a previous study. CONCLUSIONS: The results suggest that the impact of mites on nectar availability of Heliconia is more important with regard to total volume of nectar produced irrespective of flower longevity. A high variation among individuals in nectar produced in the populations was also observed. Hummingbird flower mites strongly affect availability of nectar for hummingbirds.