NIAS Public Lecture: “Macaques as seed dispersal agents in Asian forests” by Dr. Yamato Tsuji, Lecture Hall, NIAS, 1545hrs

Indian Institute of Science Campus, Bengaluru - 560 012


invites you to a






“Macaques as seed dispersal agents in Asian forests”




Dr. Yamato Tsuji

Primate Research Institute, Kyoto University



Wednesday, 14th February, 2018 at 3.45 PM

Venue: Lecture Hall, NIAS, IISc Campus, Bengaluru - 560012


Chairperson: Prof. Sindhu Radhakrishna


Abstract: Macaques are important seed dispersal agents in tropical forests, yet much is still unknown about their seed dispersal abilities. In this talk I propose to review present knowledge on the seed dispersal characteristics of macaques (Macaca spp.). The extent to which macaques serve as seed dispersal agents in temperate and tropical regions was not well established until the 1990s. The size of seeds in the fruit influences whether they are swallowed (0.5-17.1 (median: 3.0) mm seeds), spat (1-37 (median: 7.6) mm seeds), or dropped (large seeds), affecting seed dispersal characteristics. Dispersal distances via defecation are several hundreds of meters (median: 259 m, range: 0 – 1300 m), which is shorter than those by some mammals and birds in tropical (e.g., elephants, tapirs, flying foxes, hornbills, pigeons) and temperate (e.g., bears, martens, foxes) regions. However, macaques disperse seeds by defecation at comparable distances to civets, and at longer distances than passerines. Macaques also disperse seeds by spitting, but the distances (median: 20 m, range: 0 – 405 m) are much shorter than those by defecation. Among Asian primates, dispersal distances by macaques (via defecation) are comparable to those by gibbons and longer than those by langurs. Effects of seed ingestion on the percentage and speed of germination vary not only among plant species but also among macaque species, making it difficult to elucidate how ingestion affects seed fate. Seasonal and inter-annual variation in seed dispersal characteristics exist, with long-term studies on the ecological role of macaques being required. Researchers have begun assessing the effectiveness of seed dispersal by macaques, secondary dispersal of seeds originally dispersed by macaques, and the effects of intentional/non-intentional provisioning on seed dispersal, facilitating community-based evaluations. Future studies should test the redundancy of macaques in the dispersal of seeds by other frugivores and the effects of social factors (such as age and rank) on the dispersal characteristics.


About the Speaker: Yamato Tsuji is an assistant professor at the Primate Research Institute, Kyoto University, Japan. He is a primatologist who is particularly interested in the feeding ecology of primates, inter-specific interactions, and seed dispersal by mammals. His study species include Japanese macaques (Macaca fuscata), Japanese martens (Martes melampus), Javan lutung (Trachypithecus auratus) and Malayan flying lemurs (Cynocephalus (Galeopterus) variegatus) in Indonesia. Dr Tsuji completed his Masters degree and his PhD from the University of Tokyo and his PhD work looked at foraging success of female Japanese macaques (Macaca fuscata). Dr Tsuji is on the Editorial Board of Hayati and Primate Research and the Advisory Board of Primates journal. His other honours and awards include the Takashima Award in 2012 from the Primatological Society of Japan and the 8th Young Researcher Award in 2010 from the Mammalogical Society of Japan. His paper with Dr Goro Hanya and DR Cyril C Grueter on Feeding strategies of primates in temperate and alpine forests won the Most Cited Paper Award from Primates in 2015.


All are cordially invited


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For further information, please contact Prof. Sindhu Radhakrishna  <>

Wednesday, February 14, 2018