The diet of insectivorous cave-dwelling bats from Gombong Karst Area, Central Java, Indonesia

This research aims to determine the prey preference of cave dwelling insectivorous bats in the Gombong Karst Area, Kebumen, Central Java. The research was done from March 2009 to July 2010. Stomach and mouth contents were taken from collected specimens and dissolved in aquadest. The ingested insects were sorted and identified under a microscope, and compared with insects collected by light trap in nearby bat foraging areas. The data were analysed by Principle Component Analysis (PCA), x^2 and niche overlap index. Eleven species of insectivorous bat were identified. The insects in the gut contents of the bats belonged to 10 orders, distributed into 29 families. Based on prey preference, the bats can be classified into four groups as follows, Group 1: Chaerophon plicata, Hipposideros sp., H sorenseni and H diadema, which chose hard-bodied and large sized insects as their prey; Group 2: Miniopterus schreibersii, M australis, H cf. ater, and Rhinolophus borneensis, which prefer soft bodied and medium sized insects; Group 3: R. affinis, which chose hard-bodied and small size insects and Group 4: H bicolor and H ater which chose soft body and small size insects as their prey. The niche overlap index between the species of bats that occupy one cave was less than30%.