Importance of Green Areas for Insectivorous Bat Activity

Abstract

The impact of urbanization might differ between insectivorous bats that forage in open space as opposed to edge space, with the latter usually persisting only in well preserved areas, such as parks and natural reserves. We investigated the influence of vegetation patches of different sizes on the activity of these two groups of insectivorous bat in the urban area of the Metropolitan region of Vitória, Espírito Santo State, Brazil. For this purpose, we monitored bat activity with an ultrasound detector for a total of two years in three habitats: large-green areas (> 30ha), small-green areas (< 5 ha) and non-green areas. Large-green areas showed the greatest bat activity followed by small-green areas and non-green areas. Although both groups of bats showed an increase in activity in the green areas compared to the non-green areas, this effect was higher for edge-space foragers than for open-space foragers in the large green-areas, whereas in the small green areas, the increment in activity did not differ between them. We also present a list of eight species we identified in the study area. Two of the species represent the first record for the region: Promops centralis and Peropteryx trinitatis. We conclude that in the Metropolitan Region of Vitória, even small parks are important for bat fauna conservation and, despite being more adapted to urban environments, even open-space foraging bats can benefit from them.