1. Department of Biology, Faculty of Mathematics and Natural Sciences, IPB University, 16680 Bogor, West Java, Indonesia
2. Department of Biology, Faculty of Mathematics and Natural Sciences, Andalas University, Padang, West Sumatra, Indonesia
3. Primate Research Centre, IPB University, 16680 Bogor, West Java, Indonesia
4. Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan
5. Department of Science and Engineering, Ishinomaki Senshu University, Ishinomaki, Miyagi 986-8580, Japan