Asunto(s)

RESUMEN

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.

RESUMEN

We studied the leaf-litter frog community of Estação Ecológica Estadual Paraíso, in Guapimirim, Rio de Janeiro State, southeastern Brazil. Herein we combined three sampling methods (large plots, visual encounter surveys and pit-fall traps) to present data on species composition, richness, relative abundance and densities. The local assemblage of frogs associated to the leaf-litter was composed by 14 species, belonging to nine families. Haddadus binotatus, a direct-developing frog, was the most abundant species in the community. The estimated density of the local leaf-litter frog assemblage based on plot sampling was 4.3 frogs/100 m². Haddadus binotatus had the highest density (1.1 ind/100 m²). Frogs were predominantly found at night. Thoropa miliaris had the largest values of SVL (39.0 ± 10.3 mm), whereas the smallest species were Euparkerella brasiliensis (16.7 ± 2.2 mm) and E. cochranae (16.0 ± 2.7 mm). Rhinella ornata had the highest mean body mass (12.1 ± 7.5 g), and E. cochranae the lowest (0.4 ± 0.2 g). The overall frog mass was 938.6 g/ha. Our data support that higher densities of leaf-litter frogs tend to occur in the Neotropical region compared to the OldWorld tropics, tending to be higher in Central America than in South America.

Estudamos a comunidade de anuros de folhiço da EstaçãoEcológica Estadual Paraíso, em Guapimirim, estado do Rio de Janeiro, no sudeste do Brasil. Combinamos três métodosde amostragem (plots, transectos e armadilhas de queda) para apresentar dados sobre a composição de espécies, riqueza,abundância relativa e densidade. A assembleia local foi composta por 14 espécies de anuros, pertencentes a nove famílias. Haddadus binotatus, espécie de desenvolvimento direto, foi a mais abundante durante o estudo. A densidade de anuros de folhiço estimada com base na amostragem por plots foi de4,3 ind/100m². Haddadus binotatus apresentou a maior densidade (1,1 ind/100m²). Os anuros foram registrados predominantemente durante a noite. Thoropa miliaris apresentou os maiores valores de CRC (39,0 ± 10,3 mm). As menores espécies foram Euparkerella brasiliensis (16,7 ± 2,2 mm) e E. cochranae (16,0 ± 2,7mm). Rhinella ornata apresentou a maior massa corporal média (12,1 ± 7,5 g) e E. cochranae (0,4 ± 0,2 g) a menor. A massa média total foi de 938,6 g/ha. Nossos resultados corroboram com a tendência de maiores densidades de anuros de folhiço na região Neotropical quando comparado com áreas Tropicais do Velho Mundo, tendendo a serem maiores na América Central do que na América do Sul.

Asunto(s)

RESUMEN

We studied the leaf-litter frog community of Estação Ecológica Estadual Paraíso, in Guapimirim, Rio de Janeiro State, southeastern Brazil. Herein we combined three sampling methods (large plots, visual encounter surveys and pit-fall traps) to present data on species composition, richness, relative abundance and densities. The local assemblage of frogs associated to the leaf-litter was composed by 14 species, belonging to nine families. Haddadus binotatus, a direct-developing frog, was the most abundant species in the community. The estimated density of the local leaf-litter frog assemblage based on plot sampling was 4.3 frogs/100 m(2). Haddadus binotatus had the highest density (1.1 ind/100 m(2)). Frogs were predominantly found at night. Thoropa miliaris had the largest values of SVL (39.0 ± 10.3 mm), whereas the smallest species were Euparkerella brasiliensis (16.7 ± 2.2 mm) and E. cochranae (16.0 ± 2.7 mm). Rhinella ornata had the highest mean body mass (12.1 ± 7.5 g), and E. cochranae the lowest (0.4 ± 0.2 g). The overall frog mass was 938.6 g/ha. Our data support that higher densities of leaf-litter frogs tend to occur in the Neotropical region compared to the OldWorld tropics, tending to be higher in Central America than in South America.

Asunto(s)

RESUMEN

We studied the ecology of ticks found in different species of a taxocenosis of snakes from the Serra do Mendanha, an area of Atlantic Rainforest located in the state of Rio de Janeiro, southeastern Brazil. Snakes were sampled monthly in the field during a period of 48 months. The specific identity of the hosts and their parasites, the number of parasites, and and snout-vent length and body mass of each host were recorded. A total of 25% of the species of snakes in the area were parasitized by ticks (larvae, nymphs and adult females) Amblyomma rotundatum Koch, 1844 was the predominant parasite species. The infestation parameters varied among the species of snakes sampled, with the highest prevalence of A. rotundatum being observed in the viperid Bothrops jararaca (Wied, 1824) (71.4%), followed by the colubrids Xenodon neuwiedii Günther, 1820 (33%), Chironius laevicollis (Wied, 1824) and Spilotes pullatus (Linnaeus, 1758) (both with 22%). The latter three species also showed the highest rates of infestation by A. rotundatum. The results of the present study suggest that a combination of skin shedding, habitat of the host, type of scale and pattern of scale distribution on the body of the host can influence the degree to which a given species is parasitized by ticks

RESUMEN

We studied the ecology of ticks found in different species of a taxocenosis of snakes from the Serra do Mendanha, an area of Atlantic Rainforest located in the state of Rio de Janeiro, southeastern Brazil. Snakes were sampled monthly in the field during a period of 48 months. The specific identity of the hosts and their parasites, the number of parasites, and and snout-vent length and body mass of each host were recorded. A total of 25% of the species of snakes in the area were parasitized by ticks (larvae, nymphs and adult females) Amblyomma rotundatum Koch, 1844 was the predominant parasite species. The infestation parameters varied among the species of snakes sampled, with the highest prevalence of A. rotundatum being observed in the viperid Bothrops jararaca (Wied, 1824) (71.4%), followed by the colubrids Xenodon neuwiedii Günther, 1820 (33%), Chironius laevicollis (Wied, 1824) and Spilotes pullatus (Linnaeus, 1758) (both with 22%). The latter three species also showed the highest rates of infestation by A. rotundatum. The results of the present study suggest that a combination of skin shedding, habitat of the host, type of scale and pattern of scale distribution on the body of the host can influence the degree to which a given species is parasitized by ticks

RESUMEN

We studied the ecology of ticks found in different species of a taxocenosis of snakes from the Serra do Mendanha, an area of Atlantic Rainforest located in the state of Rio de Janeiro, southeastern Brazil. Snakes were sampled monthly in the field during a period of 48 months. The specific identity of the hosts and their parasites, the number of parasites, and and snout-vent length and body mass of each host were recorded. A total of 25% of the species of snakes in the area were parasitized by ticks (larvae, nymphs and adult females) Amblyomma rotundatum Koch, 1844 was the predominant parasite species. The infestation parameters varied among the species of snakes sampled, with the highest prevalence of A. rotundatum being observed in the viperid Bothrops jararaca (Wied, 1824) (71.4%), followed by the colubrids Xenodon neuwiedii Günther, 1820 (33%), Chironius laevicollis (Wied, 1824) and Spilotes pullatus (Linnaeus, 1758) (both with 22%). The latter three species also showed the highest rates of infestation by A. rotundatum. The results of the present study suggest that a combination of skin shedding, habitat of the host, type of scale and pattern of scale distribution on the body of the host can influence the degree to which a given species is parasitized by ticks