Gisele R. Winck

Population ecology of Tupinambis merianae (Squamata, Teiidae): home-range, activity and space use

The activity and space parameters (home range and use of space) for a population of Tupinambis merianae was recorded through 640 h of observation during nine months, and by monitoring 56 marked individuals. There was a significant difference in activity in the periods stipulated in this study throughout the months. Active lizards were not registered before 7:30 a.m., nor after 6:00 p.m. The greatest level of activity by the individuals occurred during November and December. Fluctuations in the population size and in the activity of the different age classes were recorded throughout the studied months. We recorded the minimum home-range of three males and two females, which varied from 0.05 to 26.44 ha. We also observed agonistic interactions. The utilization area of the animals did not vary during the studied months, but it was possible to observe gregarious behavior in spatial use. The highest daily activity occurred at the hours of higher temperatures. The positive correlation between seasonal activity and the maximum temperature (air and substrate) showed a unimodal distribution and was identical to the records from a tropical area (southeastern Brazil). It is possible that temperature is not the only environmental variable/factor that influences the seasonal activity cycle of the species. Although teiids are not considered territorial, some of our results could suggest territoriality in the studied population.

Seasonal, daily activity, and habitat use by three sympatric pit vipers (Serpentes, Viperidae) from southern Brazil

Viperid snakes are widely distributed in the South America and the greater distribution range of the family is found at the Crotalinae subfamily. Despite the abundance of this snakes along their geographic distribution, some ecological aspects remain unknown, principally at subtropical areas. In the present study, we evaluated the activity (daily and seasonal) and the use of the habitat by Bothrops diporus, B. jararaca and B. jararacussu, in an Atlantic Forest area at southern Brazil. We observed higher incidence of viperid snakes during the months with higher temperatures, while no snakes were found during the months with lower temperatures. The data suggest the minimum temperature as environmental variable with the greatest influence on the seasonal activity of this species. Considering the daily activity, we observed a tendency of snakes to avoid the warmest hours. Bothrops jararacussu tend to avoid open areas, being registered only inside and at the edges of the forest. We compared our results with previous studies realized at tropical areas and we suggest the observed seasonal activity as an evolutive response, despite the influence of the different environmental variables, according to the occurence region.

Anurans from the “Restinga” of Parque Natural Municipal de Grumari, state of Rio de Janeiro, southeastern Brazil

We present a list of the anuran amphibians from “restinga” of Grumari, part of the Parque Natural Municipal de Grumari (PNMG), Rio de Janeiro municipality, state of Rio de Janeiro, southeastern Brazil. This study was carried out from May 2009 to December 2010 using two active sampling methods: quadrant plots and acoustic/visual transects. We recorded 22 anuran species distributed in six families: Bufonidae (1 species), Craugastoridae (1), Hylidae (14), Leptodactylidae (3), Microhylidae (2) and Strabomantidae (1). The presence of endangered and endemic species evidence Grumari’s importance as an area for conservation of the “restinga” habitat remnants in Rio de Janeiro. Grumari is also one of the richest known areas in terms of amphibian species among the “restinga” areas studied to date in Brazil, second only to Mata de Sao Joao, Bahia.

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.

New host records for Amblyomma rotundatum (Acari: Ixodidae) from Grussaí restinga, Rio de Janeiro, Brazil

Amblyomma rotundatum Koch is a parthenogenetic tick usually associated with reptiles and amphibians. However, relatively few studies on occurrences of ticks in wild reptile populations in Brazil have been produced. The aim of this study was to analyze the presence of ticks associated with reptile species in the Grussaí restinga, in the municipality of São João da Barra, state of Rio de Janeiro, Brazil. Between December 2010 and January 2011, 131 individuals belonging to nine species of reptiles of the order Squamata were sampled: the lizards Tropidurus torquatus (n = 51), Hemidactylus mabouia (n = 25), Mabuya agilis (n = 30), Mabuya macrorhyncha (n = 6), Cnemidophorus littoralis (n = 5) and Ameiva ameiva (n = 10); and the snakes Philodryas olfersii (n = 2), Oxyrhopus rhombifer (n = 1) and Micrurus corallinus (n = 1). The only tick species found to be associated with any of the reptiles sampled was A. rotundatum. One adult female was detected on one individual of the lizard A. ameiva, one nymph on one individual of the lizard T. torquatus and four nymphs on one individual of the snake P. olfersii. This study is the first record of parasitism of A. rotundatum involving the reptiles T. torquatus and P. olfersii as hosts. Our results suggest that in the Grussaí restinga habitat, A. rotundatum may use different species of reptiles to complete its life cycle.

Diet, Diel Activity Pattern, Habitat Use, and Reproductive Effort of Hylodes nasus (Anura: Hylodidae) in One of the World's Largest Urban Parks (Tijuca National Park), Southeastern Brazil

Abstract. Hylodes nasus is a hylodid frog species that inhabits streams in the Brazilian Atlantic Rainforest of southeastern Brazil. It is endemic to the Tijuca Massif, which includes one of the largest urban forests in the world, the Tijuca National Park, in Rio de Janeiro. We studied the diet, activity period, habitat use, and reproductive effort of H. nasus during its reproductive period. Our results showed that the species has a wide spectrum of prey items (21 categories) but feeds mainly on five prey categories (Diptera, Formicidae, Coleoptera, larvae, and other Hymenoptera). The species is diurnal and tends to present a slight decrease in activity near midday. We noted a change in microhabitat use between active (diurnal) and inactive (nocturnal) periods: active individuals mainly occupied stones, whereas inactive individuals mainly occupied low vegetation. The ovarian complement comprises a median of 88 oocytes with a mean diameter of 2.2 mm. The gathered information consists in a first approximation of the biological and ecological characteristics of the species.

Distribution extension of the Yellow Anaconda Eunectes notaeus Cope, 1862 (Squamata: Boidae) in the state of Rio Grande do Sul, Brazil

The yellow anaconda, Eunectes notaeus , was until recently considered as a species with accidental occurrence on southern Brazil, due to river floods from the Pantanal region on central Brazil. Here we provide monitoring records of a well-established population in the state of Rio Grande do Sul, and also discuss its distribution in the area.

Local Environmental Factors Influence the Structure of Frog Communities on the Sandy Coastal Plains of Southeastern Brazil

Abstract Environmental factors play an important role in structuring communities. In heterogeneous environments, where habitat structure might vary considerably, understanding how these factors shape communities is one of the most important issues in community ecology. In this context, we investigated how environmental factors contributed to the composition of five frog communities on the sandy coastal plains (restinga ecosystem) of southeastern Brazil. We sampled these ecosystems over a 2-yr period and compared five sites in relation to their habitat structure, frog species composition, species abundance, and their distribution in different mesohabitats. We found that the composition of the amphibian communities was not related systematically to habitat structure in general, but rather to the availability of spawning sites (sources of freestanding water), which appears to be the most important ecological factor structuring these communities.

Squamata, Iguania, Anolis punctatus Daudin, 1802 and Tropidurus torquatus (Wied, 1820): distribution extension and new records for Ilha Grande, state of Rio de Janeiro, southeastern Brazil

The knowledge on the insular reptile fauna from Ilha Grande (state of Rio de Janeiro, Brazil) is mostly restricted to the results of surveys carried out within a limited area, considering the island’s total area of 19,300 ha. Until now, the number of reptile species reported for Ilha Grande amounted to 25 (nine lizards and 16 snakes). Here we present the first records of two lizard species ( Anolis punctatus and Tropidurus torquatus ) for the island, raising the local reptile list to 27 species. The first one appears to be rare in the area, whereas the second species was found in a portion of the island that has not been previously surveyed for reptiles. Although the presence of T. torquatus in other insular environments may be related to anthropogenic introduction, we believe the population in Ilha Grande to be natural, considering the geological history of the island.