Efeitos da paisagem sobre uma comunidade de morcegos no sul de Minas Gerais: espécies, traços funcionais e padrões de atividade

Abstract

Land use and land cover changes are nowadays considered one of the main activities responsible for biodiversity losses around the world. This, together with the idea that these activities should intensify even more thought the 21 century makes the realization of studies focused on evaluate how biodiversity responds to these changes desirable. In this dissertation, composed by two chapters, it was evaluated how different types of land use affect the functional traits and the activity patterns of bats in a human-modified landscape located at the south region of the Minas Gerais state. In the first chapter it was evaluated how habitat amount, connectivity, and amount of landscape used by human activities (pastures, crops and silviculture) affect the functional traits of two bat groups, the Phyllostomidae bats and the Molossidae and Vespertilionidae bats(also called “aerial insectivorous bats”). For Phyllostomidae bats, the functional traits evaluated were diet type, body mass, wing load and aspect ratio, while for Molossidae and Vespertilionidae bats the evaluated traits were call duration, bandwidth, and the frequency of maximum energy of the echolocation calls. In the second chapter it was evaluated how the same landscape variables affect the foraging activity, the feeding activity, and the diversity of frequencies emitted by the aerial insectivore bat community. Moreover, it was also evaluated how the landscape variables affect the frequency of occurrence of the sonotypes recorded. The results of chapter one suggests that for Phyllostomidae bats the non-frugivore and high body mass (>25g) animals are the ones more vulnerable to the increasing of land use intensification. To Molossidae and Vespertilionidae bats the echolocation calls with durations around 5-12ms and bandwidth around 6-8 kHz were used more frequently throughtout the landscape gradient, suggesting that these vocalizations are more suited to explore the study landscape. Lanscape connectivity was the variable that showed the highest explanation power on all the functional traits evaluated. The results of chapter two suggest the fragment size, and the habitat amount in the landscape are the variables with the highest explanation power on feeding activity, and the number of frequencies used by the community, respectively. Landscape connectivity was the variable with the highest explanation power on the frequency of occurrence of the sonotypes detected.