Variação do tamanho de colônias de Molossus molossus e Molossus rufus no Estado do Rio de Janeiro, sudeste do Brasil

In the Neotropical region, knowledge of seasonal variation of bat colonies is low and appears to be fundamental to the choice of methods for estimating the total number of animals and husbandry. It was analyzed the monthly variations in the size of four colonies, two of Molossus molossus and two of Molossus rufus in Rio de Janeiro State, southeastern Brazil. A total of 60 nights of data collection was conducted in these four colonies, totaling 634 hours of work. The number of animals that comprised each colony was high, 293 and 474 in M. molossus and 165 and 363 in M. rufus. There are two types of colonies: reproductive, when it is observed increase in the number of animals during the months of reproductive activity, and not reproductive, when the colony size is larger in the months of inactive reproduction of the specie in this latitude and few bats remain in the refuge from October to February.Key words: Seasonality, methods, Molossus molossus, Molossus rufus, Atlantic Forest.Na região neotropical, o conhecimento da variação sazonal de colônias de morcegos é reduzido e se mostra fundamental para a escolha dos métodos para a estimativa do total de animais e para o manejo. Foram analisadas as variações mensais no tamanho de quatro colônias, duas de Molossus molossus e duas de Molossus rufus no estado do Rio de Janeiro, sudeste do Brasil. Um total de 60 noites de coleta foi realizado nas quatro colônias, totalizando 634 horas de trabalho. O número de animais que compunham cada colônia mostrou-se elevado, sendo de 293 e 474 em M. molossus e de 165 a 363 em M. rufus. As colônias podem ser de dois tipos, reprodutiva, quando se observa incremento no número de animais durante os meses de atividade reprodutiva, e não reprodutiva, quando o tamanho da colônia é maior em meses de inatividade reprodutiva da espécie nesta latitude e poucos morcegos permanecem no refúgio de outubro a fevereiro.Palavras-chave: sazonalidade, métodos, Molossus molossus, Molossus rufus, Mata Atlântica

Bats from the Restinga of Praia das Neves, state of Espírito Santo, Southeastern Brazil

Studies on bat richness and diversity in coastal sand dunes ('restinga') are still scarce. Therefore, the objectives of the present study were to estimate bat richness in the restinga of Praia das Neves (state of Espírito Santo, southeastern Brazil) and to analyze species abundance. Ten sampling nights were carried out in May and July 2008, resulting in a sampling effort of 21,847.5 h.m2. We captured 125 individuals from 17 bat species. In this study, Tonatia saurophila was recorded for the first time not only in the state of Espírito Santo but also in the restinga ecosystem. The most abundant species was Artibeus lituratus with 32% of all captures. Surveys in coastal restingas are urgently needed in order to obtain more information about the bats living in this environment

Range extension of Lonchophylla peracchii (Chiroptera, Phyllostomidae) to Northeastern Brazil

Lonchophylla peracchii was recently described from Rio de Janeiro Atlantic Forest samples previously assigned to either L. bokermanni Sazima, Vizotto & Taddei, 1978 or L. mordax Thomas, 1903. The species is currently restricted to the Atlantic Forest of Southeastern Brazil. Based on museum specimens, we extend the species distribution to the Atlantic Forest of Northeastern Brazil. The specimens reported here were collected in Ilhéus, Bahia state, representing a range extension of ca. 500 km northward

A method for testing the host specificity of ectoparasites: give them the opportunity to choose

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

Temporal activity of rural free-ranging dogs: implications for the predator and prey species in the Brazilian Atlantic Forest

Domestic or free-ranging dogs (Canis lupus familiaris) can have deleterious effects on wildlife, acting as predators or competitors to native species. These impacts can be highly important in fragmented pristine habitats or well-preserved areas located in human dominated landscapes and where biodiversity values are usually high, such as those in southeastern Brazil. Here we explored the level of overlap or mismatch in the distributions of activity patterns of rural free-ranging dogs and potential wild prey (Didelphis aurita, Cuniculus paca; Sylvilagus brasiliensis) and a wild predator (Leopardus pardalis) in areas of Atlantic Forest in southeastern Brazil. We further explored the possible influence of the wild predator on the dog presence pattern detected in the territory analyzed. Our camera-trap data (714 camera-trap days) showed that while rural free-ranging dogs display a cathemeral activity pattern, with activity peaks at dusk and dawn, ocelot and prey species are mainly nocturnal. Moreover, we found no evidence of an effect of ocelot presence, the distance to human houses and the presence of native forests on site occupancy by dogs. The ocelot activity patterns in this study were similar to those already reported in previous studies. On the other hand, previous studies have indicated that that free-ranging dogs are often reported to be more diurnal, and it seems that the rural free-ranging dogs in our study area may have adjusted their behaviour to be more active at dawn and dusk periods. This might be to both maintain some overlap with potential prey, e.g. Sylvilagus brasiliensis, and also to avoid ocelots by being less active in periods when this predator is more active (which also coincides with peaks in activity for potential prey species). We hypothesize that the presence of ocelots might be influencing the temporal niche dimension of rural free-ranging dogs. As a sustainable management strategy, we propose conserving territories to promote the presence of medium to large predators in natural areas, in order to control free-ranging dogs and protect their vertebrate prey species

Ilha Grande, one of the locations with the most records of bat species (Mammalia, Chiroptera) in Rio de Janeiro state: results of a long-term ecological study

Faunal inventories provide quantitative and qualitative data for different sites and are relevant sources of information for identifying areas of high species richness and endemism. Biological collections are important in this context for increasing the precision of species identification. The objectives of this study were to update the list of bat species of Ilha Grande by analyzing specimens in zoological collections as well as records obtained in areas where no such studies had been undertaken before; to compare five different studies conducted on Ilha Grande using mist net sampling; and to compare the results of studies on Ilha Grande with sampling results from other areas in Rio de Janeiro state. The occurrence of 36 bat species was confirmed for Ilha Grande. Five studies on Ilha Grande formerly conducted by the authors were compared with 34 fauna inventories in Rio de Janeiro state. The studies on Ilha Grande had distinct objectives and sampling techniques applied to different locations in the same area. Ilha Grande is one of the regions in Rio de Janeiro state with more bat records both in terms of abundance and number of species, as well as one of the areas of highest bat capture effort