Atividade de morcegos insetívoros aéreos em resposta a luminosidade lunar, distúrbio do habitat, condições climáticas e interação presa-predador em florestas preservadas e alteradas da Amazônia Central

Abstract

Increasing deforestation and anthropogenic land use changes have devastated the Amazon rainforest and created fragmented landscapes with forests in different stages of disturbance. Bats can be indicators of environmental quality and are increasingly being used in monitoring. Aerial insectivorous bats are the least studied in the Amazon, as most studies only use mist nets, an inefficient method to register these bats. Thus, it is not understood how the activity of these bats responds to biotic and abiotic factors in preserved and disturbed forests. Therefore, in this thesis I evaluated how moonlight intensity, habitat disturbance, climatic conditions and prey-predator interaction influence the activity of aerial insectivorous bats in preserved and disturbed forests of Central Amazonia. I used acoustic monitoring data from autonomous recorders installed at Reserva Ducke and BDFFP between 2013-2019. In chapter 1, I assessed that the use of recorders proved to be the most efficient method to obtain distribution data for aerial insectivorous bats in the Amazon compared to other methods. In chapter 2, the results indicated that species responded more to moonlight intensity and temperature than to rainfall between nights. Only two species responded positively to temperature and rainfall did not limited species activity between nights and throughout the night. In chapter 3, I analyzed that habitat disturbance influences species activity more than moonlight intensity and secondary forest showed lower activity, indicating that despite ca. 30 years of forest regeneration, it is still less attractive as foraging habitat. Fragments had six species with lower activity compared to preserved forest on bright nights compared to dark nights. In chapter 4, I assessed that bat activity is negatively influenced by habitat disturbance probably due to the lower mass of insects, as I evaluated that secondary forest showed lower insect mass than preserved forest. Predation risk and moonlight intensity have weak effects on aerial insectivorous bat activity. Finally, it is suggested that in the preserved forest, moonlight intensity may have a more pronounced effect than other abiotic factors. But in disturbed forests, moonlight has a weak effect, and the lower insect mass seems to explain the lower activity of aerial insectivorous bats in these areas.