FSD 2010 - Kitamura

5th International Symposium-Workshop on Frugivores and Seed Dispersal (1985-2010)

Shumpei Kitamura

The Museum of Nature and Human Activities, Division of Nature and Environmental Management, Hyogo, Japan

kshumpei(a)wg8.so-net.ne.jp

(Photo: Shumpei Kitamura at FSD2005, Brisbane, Austalia. © Pierre-Miche Forget)

Activities

From 1998 to 2003, I focused on fruit-frugivore interactions in a tropical seasonal forest of Khao Yai National Park in Thailand, especially seed dispersal by hornbills. I carried out my thesis work at Center for Ecological Research, Kyoto University, Japan, under the supervision of Drs. Takakazu Yumoto (Center for Ecological Research, Kyoto University, Japan) and Pilai Poonswad (Faculty of Science, Mahidol University, Thailand) and received PhD (Science) in March 2003. From 2004 to 2008, I conducted post-doc project founded by Mahidol University under the Thailand Hornbill Project, entitled "Assessment of the effect of hornbill loss in the seed dispersal process in tropical forests: comparison of the fruit removal, seed predation, and seedling dynamics of hornbill-dispersed plants between intact forests and degraded forests".

Abstract

Frugivory and seed dispersal by hornbills (Bucerotidae) in tropical forests.

Hornbills are known to be largely frugivorous and are believed to be important seed dispersal agents in their habitats. I review the recent studies on the following three questions about hornbills as seed dispersers: (1) Do they eat fruits? (2) Do they defecate, regurgitate, spit or drop potentially viable seeds away from the parent plant? (3) Are they significant dispersal agent? Some degree of frugivory has been reported for almost all hornbill species, especially for Asian hornbills. Despite their high frugivory, most hornbill studies could not answer the question (2). A few studies examined the viability of seeds that were defecated or regurgitated by hornbills. Hornbill visit lengths, visit frequencies, and seed passage times indicated that few seeds were deposited beneath parent plants. To answer the third question is more difficult, because it is hard to determine a seed disperser’s significance for a plant. Several fruit species are considered as being exclusively consumed by hornbills. It has been asserted that large hornbills are the major consumers of the fruits from many primary forest plants with one large-seeded fruits. Although the seed dispersal by hornbills at nest trees during the breeding season and roosting trees are inefficient from the point of view of the plant, the extent of hornbill seed shadows suggests that their influence in determining forest structure will likely increase as other larger mammalian dispersers are exterminated.

Recent references

Kitamura, S., Thong-Aree, S., Madsri, S., & Poonswad, P. (2010) Mammal diversity and conservation in a small isolated forest of southern Thailand. Raffles Bulletin of the Zoology 58 (in press).

Kitamura, S., Suzuki, S., Yumoto, T., Wohandee, P., & Poonswad, P. (2009) Evidence of the consumption of fallen figs by Oriental Pied Hornbill Anthracoceros albirostris on the ground in Khao Yai National Park, Thailand. Ornithological Science 8:75-79.

Kitamura, S., Yumoto, T., Noma, N., Chuailua, P., Maruhashi, T., Wohandee, P., & Poonswad, P. (2008) Aggregated seed dispersal by wreathed hornbills at a roost site in a moist evergreen forest of Thailand. Ecological Research 23:943-952.

Kitamura, S., Yumoto, T., Poonswad, P., Suzuki, S., & Wohandee, P. (2008) Rare seed-predating mammals determine seed fate of Canarium euphyllum, a large-seeded tree species in a moist evergreen forest in Thailand. Ecological Research 23:169-177.