Fenologia reprodutiva e condição corpórea de três espécies de morcegos insetívoros no sudeste do Pantanal

Abstract

Variations in climatic conditions and resource availability strongly influence the development and reproductive phases of species, known as phenology. Insectivorous bats tend to exhibit different reproductive patterns with changes in latitude and altitude, due to different climate zones. Body condition is influenced by available resources in the environment and foraging success. High values of the Body Condition Index (BCI) indicate the accumulation of energy stored in the individual, which interferes in the phenophases and trigger reproduction. In this study, we describe the reproductive phenology and body condition of three insectivorous bats (Myotis nigricans, Molossus molossus and Noctilio albiventris) in the Southern Pantanal (subregions of Nhecolândia, Aquidauana and Miranda), using a database from 1998 to 2009. The Pantanal has long and marked wet and dry seasons. Insects are available in greater numbers during the rainy season in the Pantanal. Molossus molossus presented a seasonal monoestrous reproductive pattern, alongside a reproductive cycle that is aligned with the period of pronounced food availability in the Pantanal, during the rainy season. Higher body condition values for adult males, and pregnant and lactating females were registered during the rainy season, as expected due to the greater number of insects in the environment. Myotis nigricans presented a polyestrous reproductive pattern, however, our results do not allow us to identify whether there was a seasonal pattern or a long aseasonal reproduction. The highest BCI values of reproductive females, adult males and non-reproductive adult females were found during the dry season, while young males and females were during the rainy season. Overall, there were no major differences in BCI between gender and ages. Noctilio albiventris presented a bimodal polyestrous pattern, with reproductive cycles during the rainy and dry seasons. The BCI fluctuated in both genders during the two seasons, due to reproductive and foraging patterns.