|| 要旨トップ | 目次 |||日本生態学会第65回全国大会 (2018年3月、札幌) 講演要旨
一般講演（口頭発表） H02-03 （Oral presentation）
We evaluated the contribution of three arboreal or volant frugivores in the seed dispersal of hemi-epiphytic figs by the seed dispersal effectiveness (SDE) landscape. Hemi-epiphytic (HE) figs occupy one third to over half of the fig species in any communities, and are considered to be keystone food resources for many animals due to large crops and a continuous fig availability. Despite of their ecological importance, little has been reported on their seed dispersal systems.
HE figs’ seeds germinate in crowns of host trees, and thereby the seed dispersers must be arboreal or volant animals. The seeds require consistently moist condition for germination rather than light level. Therefore, defecation habits of dispersal animals are relevant to their seed fates. In this study, we focused three relatively large frugivores, East Bornean grey gibbons Hylobates funereus, binturongs Arctictis binturong, and helmeted hornbills Rhinoplax vigil, and investigated both quantitative and qualitative effectiveness of seed dispersers of HE figs on Borneo.
Our results suggest that binturongs are by far the most effective seed dispersers of HE figs especially when they defecates on tree forks. Gibbons and helmeted hornbills provide similar seed dispersal services. Even though binturongs exhibit high quantity effectiveness, the SDE were quite different by the defecation sites. Gibbons and hornbills are usually considered as effective seed dispersal agents in South-eastern Asian rainforests. However, this study indicates that binturongs are the most effective amongst the three species.