1. National University of Singapore, Department of Biological Sciences, 14 Science Drive 4, Singapore 117543.
2. Division of Zoology, Research Center for Biology, Indonesian Institute of Sciences (LIPI), Jalan Raya Jakarta Bogor KM 46, Cibinong Science Center, Cibinong 16911, Indonesia.
3. Department of Conservation and Research, Wildlife Reserves Singapore, 80 Mandai Lake Road, Singapore 729826.