Habitat characteristics and insectivorous bat activity
Almeida, Márcio HenriqueDitchfield, Albert DavidTokumaru, Rosana Suemi
Some factors that influence insectivorous bat activity in the temperate regions have been identified through the use of ultrasound detector. However, the factors that might influence Neotropical insectivorous bat activity remain poorly known. The major objective of our work is to check if spatial complexity of vegetation and bodies of water also influences insectivorous bat activity in the Neotropics. The number of bat passes was counted using an ultrasound detector for eight nights, randomly distributed through one year, in an area of Atlantic forest in Southeastern Brazil. Two types of comparisons were carried out: first between forested, forest edge and open habitat, and second between open habitat with and without a water body nearby. All these areas were sampled in the same eight nights, for five minutes in each site. The number of feeding buzzes was also recorded for the second comparison. For the first comparison the largest and smallest number of bat passes was counted respectively for edge and forested habitat. Bat passes occurred in the forested habitat only in the beginning of the night, suggesting that this habitat was used for roosting with foraging occurring in the other habitats. For the second comparison, open habitat with water had a greater number of bat passes and feeding buzzes than open habitat without water. This result suggests that insectivorous bat activity in the Neotropics is also influenced by spatial complexity of vegetation and the presence of bodies of water, as has been documented for the temperate zone.(AU)