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.

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.

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.

Host-choice experiments were carried out with rodent and bat ectoparasites on Ilha Grande, state of Rio de Janeiro, Brazil. We constructed experimental chambers that enclosed three different rodent or bat host species, and then introduced a selected set of ectoparasitic arthropods. When given the opportunity to choose among host species, the ectoparasites showed a strong tendency to select their primary hosts, and reject novel host species. These kinds of simple experiments can be valuable tools for assessing the ability of ectoparasites to locate and discern differences between host species, and make choices about which hosts to infest, and which hosts to avoid.