ABSTRACT Body condition is an important measure to estimate the energy reserve of an organism. Scientists frequently use body condition indices (BCIs) with morphometric measures but direct measurements, such as blood glucose, seem to be more reliable. We observed oscillations in the body condition and glucose indexes of individuals of Artibeus planirostris (Spix, 1823) during 13 nights in the field. We assume that if glucose levels are proportional to feeding state and body condition is a measure of energy reserve, blood glucose and BCI should be positively correlated and both are expected to increase during the night as the bats leave their diurnal roost to feed. To test this, we examined the relationship between blood glucose levels, BCI and reproductive phase of free flying male bats (n = 70) for 12 hours after sunset for 13 nights. Bats were captured in Reserva Biológica de Guaribas (Paraíba, Brazil) using mist nets. Blood glucose was analyzed with a portable glucometer. Supporting our assumptions, the number of hours after sunset and BCI presented significant positive correlations with glucose levels in A. planirostris. Reproductive phase did not present a significant correlation with any other variables. As we predicted, glucose level can be used as proxy for morphometric BCI and it can be measured with a simple portable glucometer. The increase both in glucose and BCI around the night can be explained by the efficient assimilation of nutrients present in fruits ingested by bats and the quick metabolism that increases the levels of glucose (an other nutrients) in blood, increasing the body mass.

Resumo O Rio Grande do Norte é um dos menores estados do Brasil, mas possui grande diversidade de ecossistemas, incluindo vegetação de Caatinga, Mata Atlântica, habitats costeiros, manguezais e grandes áreas cársticas com cavernas. No entanto, a fauna de quirópteros é pouco conhecida, e o estado contém lacunas importantes sobre a ocorrência e distribuição de morcegos no Brasil. Para reduzir essa lacuna de informação, com base em uma revisão da literatura científica e coleções regionais de mamíferos, listamos 42 espécies de morcegos, incluindo novas ocorrências para 13 espécies e discusões sobre seu estado de conservação. Os resultados mostram que mais de metade (54%) das espécies registradas são morcegos filostomídeos e cerca de um terço dos morcegos no estado se abrigam em cavidades subterrâneas. A Caatinga abrigou a maior riqueza de morcegos no estado, incluindo a ocorrência de quatro espécies vulneráveis (Furipterus horrens, Lonchorhina aurita, Natalus macrourus e Xeronycteris vieirai). A Mata Atlântica precisa ser mais amostradas, incluindo manguezais, habitats costeiros e áreas de Caatinga principalmente na região central do estado (planalto da Borborema), que são virtualmente inexplorados. Embora o recente aumento das investigações no estado em relação aos morcegos, estudos futuros devem complementar os métodos convencionais de captura com procura ativa de abrigos e monitoramento bioacústico para obter melhores dados na tarefa de desvendar a diversidade de morcegos do Rio Grande do Norte.

Abstract Rio Grande do Norte is one of the smallest states in Brazil but has a rich diversity of ecosystems, including Caatinga vegetation, remnants of Atlantic Forest, coastal habitats, mangroves and large karstic areas with caves. However, its chiropteran fauna is little known, and the state contains conspicuous gaps of information on the occurrence and distribution of bats in Brazil. In order to reduce this information gap, based on a review of scientific literature and regional mammal collections, we list 42 species of bats, including new occurrences for 13 species and discussion on their conservation status. Results show that more than half (54%) of the recorded species are phyllostomid bats, and about one third of the bats in the state roosts in underground cavities. The Caatinga harbored the highest bat richness in the state, including the occurrence of four vulnerable species (Furipterus horrens, Lonchorhina aurita, Natalus macrourus and Xeronycteris vieirai). The Atlantic Forest needs to be more sampled, including mangroves, coastal habitats and areas of Caatinga in the central region of the state (Borborema highlands), which are virtually unsurveyed. Although the recent increase of studies on bats in the state, future studies should complement conventional mistnetting with active roost search and bioacoustical records in order to obtain better data for unraveling the bat fauna of Rio Grande do Norte.