Bat Activity in an Agricultural Landscape in Central Thailand

Abstract

The agricultural landscape which is croplands mixed with semi-natural habitats, is common in Asia as well as in central Thailand. Agricultural areas with homogeneous characteristics most often found to have a negative impact on biodiversity. In order to maintain ecosystem services, we must have information about the habitat use of wildlife in the landscape. Little is known about habitat use of insectivorous bats in agricultural landscapes in Asia. The objectives of this study are determining foraging habitat and activities of insectivorous bats and to assess seasonal variation in foraging habitat and activities of insectivorous bats in an agricultural landscape central of Thailand via acoustic monitoring. Anabat Bat detector are carried out in real time with the data save to computer hard- drive in 5 land use types paddy fields, field crops, forests, settlements and water bodies for one year. During each sampling period, we detected and counted bat passes with an Analook program based upon the present or absent of a species occurrence during one- minute time interval. 37,610 one-minute interval with bat calls and 623 feeding buzzes over 227 nights, representing 14 bat species were recorded. Bats showed highest activity in water bodies, which was significantly higher than all other land use types (p < 0.001). This may be explained by the availability of aquatic insects. There was a significantly higher bat activity index in the hot-dry season than at other seasons (p < 0.001) especially over water bodies. This pattern was obvious in Myotis siligorensis, Taphozous melanopogon and Chaerephon plicatus. The hot-dry season is the main breeding period of most bats in this region. High feeding activity during this period could reflect higher nutrient and water demand of lactating females. Thus, maintaining water bodies and its surrounding woodlands facilitate existing of diverse bat community in agricultural landscape.