Reproductive biology of the bat Sturnira lilium (Chiroptera, Phyllostomidae) in the Atlantic Forest of Rio de Janeiro, southeastern Brazil.

Bats can be monoestrous or polyestrous, and seasonal or non-seasonal in their reproductive patterns. The strategy adopted by each species or population depends on the regional climate. The objective this study was to analyze reproductive data of Sturnira lilium from long-term sampling carried out in several sites in Rio de Janeiro states, southeastern Brazil. We carried out sampling in 42 sites (with altitudes ranging from sea level to 1300 m a.s.l.) from May 1989 to December 2011. In total, we obtained 2602 captures of S. lilium: 1242 captures of adult females, 1225 captures of adult males, and 136 captures of subadults. The sex ratio was 0.99 males: 1 female. The reproductive season varied from eight to twelve months a year, and it was not related to the total accumulated rainfall. Sturnira lilium have continuously polyestrous reproduction with postpartum estrus and pregnant females can be observed in all months except July. In the present study, the highest proportions of pregnant females were observed in the months with the highest rainfall.

Comparison of two mammalian surveys made with camera traps in southeastern Brazil, focusing the abundance of wild mammals and domestic dogs.

Sampling allows assessing the impact of human activities on mammal communities. It is also possible to assess the accuracy of different sampling methods, especially when the sampling effort is similar. The present study aimed at comparing two mammalian surveys carried out over a three-year interval, in terms of sampling effort, capture success, abundance of domestic dogs, impact of human activities, and relative biomass using camera traps, in the Serra do Japi Biological Reserve and surroundings, located in Jundiaí, state of São Paulo, southeastern Brazil. The total richness recorded was 13 species, one domestic and 12 wild mammals. Sampling effort in both surveys was similar, but capture success and number of captures differed. The abundance of wild mammals and dogs did also differ between surveys. There was a highly significant correlation between abundance of wild mammals and capture effort for the survey performed in 2006/2007, but not for the survey performed in 2009/2010. The difference between samples may be related to human disturbance, since the number of domestic mammals photographed was higher in the second survey, three years after the first survey. Despite being a reserve, the area is still under pressure from urbanization, biological invasion, environmental degradation, and hunting, which may reduce the abundance of wild mammals.

Do young Carollia perspicillata (Chiroptera: Phyllostomidae) present higher infestation rates of Streblidae (Diptera)?

Ecological aspects related to parasitism are one of the less studied issues in parasitology research, and the scarce evidence available supports that younger specimens present higher infestation rates. The purpose of this work is to establish if higher infestation rates are observed in nursing females and their young captured inside their roost. Bats were captured inside a shelter located in RPPN Estação Veracel, Santa Cruz de Cabrália, Bahia state, Brazil. A total of 56 individuals of Carollia perspicillata were observed, 17 captured inside the roost during the day and 39 in trails at night. Captures of C. perspicillata during the day in a shelter yielded similar infestation rates to bats netted in trails and higher prevalence. The hypothesis that young were more infected was confirmed, based on the higher infestation of nursing females with neonates and on the significant inverse relation between body weight and number of parasites in young and subadults.

Reproduction of Phylloderma stenops in captivity (Chiroptera, Phyllostomidae).

A reproductive colony of Phylloderma stenops was established in captivity. The bats were maintained in 1/2" wired screen cages sized 90 × 60 × 80 cm in a room with cycles of 13 hours of light and 11 hours of dark and with temperature and humidity ranging from 27 to 31 °C and 75 to 90% respectively. Bats were fed with a semi-liquid diet composed of chopped fruits, raw eggs, bovine meat, dog food, honey, dehydrated shrimp, salt and a vitamin and mineral complex offered daily. In the first two years of confinement the diet was complemented with laboratory-raised cockroaches, mealworms, young mice and seasonal fruits. Nine births occurred from three wild caught females 770-1050 days after capture and two captive-born females. Births occurred in September, February and November-December. The neonate measured 15.0 g of weight and present 34.1 mm of forearm length. Two captive-born females gave birth for the first time at 402-445 days of age. Phylloderma stenops species presents postpartum oestrus, gestation of 5.5 months, lactation of 3.3 months and sexual maturity at 8.0-8.5 months. Fetuses are palpable around two months before birth and females may present synchronisation of births.

Desmodus rotundus (Mammalia: Chiroptera) on the southern coast of Rio de Janeiro state, Brazil.

Since the 1990s, attacks by hematophagous bats on humans and domestic animals have been reported both on the continent and on the islands on the southern coast of Rio de Janeiro state. The density of vampire bats was investigated based on percentage of captures during control of Desmodus rotundus samplings and during bat diversity research. In the present work, 203 individuals of D. rotundus were captured from 1993 to 2009, which corresponds to 11.88% of all bat captures carried out for species control in local villages and 1.58% of all captures in faunistic inventories. The density of D. rotundus is high even on the recently occupied islands where domestic animals have been introduced. It is probable that this species dispersed from the continent to the islands due to the introduction of domestic animals.

Foraging activity of the free-tailed bat Molossus molossus (Chiroptera; Molossidae) in southeastern Brazil.

Sunset and sunrise regulate the activities of most studied bat species. To verify patterns of foraging activity, 29 bat sampling nights were carried out over a dam in Rio de Janeiro city, which resulted in 363 hours with 730 captures, representing 13 species of insectivorous bats. Molossus molossus constituted the bulk of the captures (79.9%) and was present in 82.8% of the sampling nights. This bat species exhibited crepuscular and nocturnal activity (from -6 minutes to 900 minutes after the time of sunset). A bimodal activity pattern was observed, and two non-overlapping capture peaks. The first peak lasted from 6 minutes before sunset to 420 minutes after sunset. The second peak began at 564 minutes after sunset and ended just after sunrise. The first capture peak was observed in 75.9% of the nights, and the second peak in 62.1% of the nights. The time of the first capture exhibited a positive linear relationship with sunset and the time of the last capture, a positive linear relationship with sunrise. The existence of a relationship between night length and the difference between first and last captures of each night shows that M. molossus has longer activity the longer the night, showing a seasonal variation in the activity period.

Colony size, sex ratio and cohabitation in roosts of Phyllostomus hastatus (Pallas) (Chiroptera: Phyllostomidae).

Phyllostomus hastatus bat is species broadly distributed over the Neotropical region, which uses as diurnal roosts caves, hollow trees, palm leaves and human buildings. Thirteen diurnal roosts of P. hastatus were analysed from 1990 to 2009 in several localities of Rio de Janeiro State, regarding environment (rural, urban or protected area), type of roost (hollow tree, basement or roof), sex ratio and cohabitation. A nocturnal roost was also analysed. Sex ratio of P. hastatus varied considerably among roosts what may be explained by the fact this species can roost alone, in couples, in harems or in groups of bachelor males. Phyllostomus hastatus was observed in cohabitation with three other species: Molossus rufus, Molossus molossus and Myotis nigricans. Due to the frequency of cohabitation observed between P. hastatus and species of the genus Molossus, one or more advantages for the members of this association may be expected. The simultaneous usage of a feeding roost by a group of bachelor males is unknown information in the literature, and may suggest that this kind of group may interact with each other even when away from their diurnal roosts.

Bat diversity of Ilha da Marambaia, Southern Rio de Janeiro State, Brazil (Chiroptera, Mammalia).

Few sites have been well sampled for bats, and samplings in islands are even scarcer. Therefore, the objectives of the present study were: (1) to list the bat species of Ilha da Marambaia; (2) to compare richness, abundance and biomass of bat guilds found there; (3) to analyse abundance patterns of bat species; and (4) to compare richness, abundance and composition of the bat fauna among different kinds of environment. To capture bats we used mist nets set in five different environments, totalising 3559.2 net-hours, during 37 nights between October 2006 and August 2008. A total of 1,133 captures were accomplished, comprising 34 species from five families. The most abundant species was Molossus molossus. Frugivorous bats exhibited higher richness, abundance and biomass if compared to other guilds. Most species (N = 22) exhibited abundances between 1 to 10% of all captures. Sixteen species were restricted to just one of the environments sampled. The high richness may be attributed to sampling carried out in several environments, and to the capture of insectivorous species over water bodies.

Bat diversity of Ilha da Marambaia, Southern Rio de Janeiro State, Brazil (Chiroptera, Mammalia) / Diversidade de morcegos da Ilha da Marambaia, Sul do Rio de Janeiro, Brasil (Chiroptera, Mammalia)

Few sites have been well sampled for bats, and samplings in islands are even scarcer. Therefore, the objectives of the present study were: (1) to list the bat species of Ilha da Marambaia; (2) to compare richness, abundance and biomass of bat guilds found there; (3) to analyse abundance patterns of bat species; and (4) to compare richness, abundance and composition of the bat fauna among different kinds of environment. To capture bats we used mist nets set in five different environments, totalising 3559.2 net-hours, during 37 nights between October 2006 and August 2008. A total of 1,133 captures were accomplished, comprising 34 species from five families. The most abundant species was Molossus molossus. Frugivorous bats exhibited higher richness, abundance and biomass if compared to other guilds. Most species (N = 22) exhibited abundances between 1 to 10 percent of all captures. Sixteen species were restricted to just one of the environments sampled. The high richness may be attributed to sampling carried out in several environments, and to the capture of insectivorous species over water bodies.

Poucos são os locais satisfatoriamente amostrados para morcegos e menos ainda as ilhas. Os objetivos deste estudo foram listar as espécies de morcegos da Ilha da Marambaia, comparar a riqueza, abundância e biomassa das guildas de morcegos encontradas, analisar o padrão de abundância das espécies de morcegos e comparar a riqueza, abundância e composição entre os diferentes ambientes amostrados. O método de amostragem consistiu do uso de redes de neblina armadas em cinco ambientes diferentes, totalizando 3559,2 redes-hora, em 37 noites entre outubro de 2006 e agosto de 2008. Foram obtidas 1.133 capturas, compreendendo 34 espécies de cinco famílias. A espécie mais abundante foi Molossus molossus. Os frugívoros apresentaram maior riqueza, abundância e biomassa. A maior parte das espécies (N = 22) apresentou abundâncias entre 1 e 10 por cento do total de capturas. Dezesseis espécies foram restritas a apenas um dos ambientes amostrados. A elevada riqueza encontrada pode ser atribuída à realização de coletas em vários ambientes, e a captura de espécies insetívoras sobre a água.

Biology of Vampyressa pusilla (Wagner) in Rio de Janeiro State, southeastern Brazil (Mammalia, Chiroptera, Phyllostomidae).

Vampyressa pusilla is widespread in Rio de Janeiro State, southeastern Brazil. It occurs in forested areas, and is absent from urban and open habitats. This species occurs mainly in altitudes up to 1,300 m a.s.l. Vampyressa pusilla was captured during the whole night, from 18 minutes before sunset to 759 minutes after sunset. Captures peaked in the first two hours of the night. Reproductive activity was seasonal, pregnant females were observed in January, February, April, August, October, November and December and lactating females from November to January and in March.

Bat community species richness and composition in a restinga protected area in Southeastern Brazil.

In Brazil, restingas are under severe human-induced impacts resulting in habitat degradation and loss and remain one of the less frequently studied ecosystems. The main objectives of the present study are to describe the bat community in a restinga in Paulo Cesar Vinha State Park, Guarapari municipality, state of Espírito Santo, southeastern Brazil. Fieldwork was conducted twice a month from August 2004 to September 2005. A total sampling effort of 40,300 m(2)/h, represents the largest sampling effort for sampling bats in restingas to date. Bats were sampled in five different vegetational types in the area. Captured bats were processed recording information on species, sex, age, forearm length and weight. Shannon Diversity and Jaccard indexes were used to analyse diversity and similarity among habitats in the Park. A total of 554 captures belonging to 14 species and two families were obtained. Noctilio leporinus was recorded through direct observation and an ultra-sound detector also registered the presence of individuals from the family Molossidae, without being possible to distinguish it at specific level. Frugivores were the most representative guild. Richness was higher in Clusia shrubs (11 species) and Caraís lagoon (10 species). Shannon diversity index was estimated at H' = 1.43 for the overall sample, with Caraís lagoon representing the most diverse habitat (H' = 1.60). The greater similarity (J = 0.714) was observed for the two areas under high human influence.

Do bigger bats need more time to forage? / Maiores morcegos precisam de mais tempo de forrageamento?

We test the hypothesis is that bats using the same area and at the same time would be using similar preys, but they would have different foraging times due to specific differences in biomass. A total of 730 captures was analyzed 13 species of Vespertilionidae and Molossidae bats netted over a small dam in southeastern Brazil from 1993 and 1999. The relationship between the average time of captures and the biomass of the species of Vespertilinidae and Molossidae most frequent (captures > 4) was positive and significant (r = 0.83, p = 0.022, N = 7). Two lines are discussed to answer the longer foraging time for bigger bats: 1) larger insectivorous bats don't consume proportionally larger preys and 2) larger insects are less available.

Testamos a hipótese de que morcegos insetívoros usando a mesma área podem estar usando as mesmas presas, mas têm diferentes tempos de forrageamento devido às diferenças de biomassa. De um total de 730 capturas, foram analisadas 13 espécies de Vespertilionidae e Molossidae capturadas em redes armadas sobre um pequeno açude no Sudeste do Brasil entre 1993 e 1999. A relação entre a média do horário de captura e a biomassa das espécies de Vespertilionidae e Molossidae mais freqüentes (capturas > 4) foi positiva e significante (r = 0,83, p = 0,022, N = 7). Duas linhas são discutidas para responder ao maior tempo de forrageamento pelos maiores morcegos: (1) morcegos insetívoros maiores não consomem presas proporcionalmente maiores; e (2) maiores insetos são menos disponíveis.

Do bigger bats need more time to forage?

We test the hypothesis is that bats using the same area and at the same time would be using similar preys, but they would have different foraging times due to specific differences in biomass. A total of 730 captures was analyzed 13 species of Vespertilionidae and Molossidae bats netted over a small dam in southeastern Brazil from 1993 and 1999. The relationship between the average time of captures and the biomass of the species of Vespertilinidae and Molossidae most frequent (captures > 4) was positive and significant (r = 0.83, p = 0.022, N = 7). Two lines are discussed to answer the longer foraging time for bigger bats: 1) larger insectivorous bats don't consume proportionally larger preys and 2) larger insects are less available.