Birds Eating Fruits of a Pioneer Tree Mallotus japonicus on Iriomote Island

Abstract

Possible seed dispersal agents of a pioneer tree Mallotus japonicus were observed on Iriomote Island in the summer of 2003. When the fruit is ripe, the shell opens and exposes a clump of blackish lipid-rich seeds. The seeds attract many species of birds. Observation for four days (34hrs) at the tree stands revealed four species of birds, the Jungle Crow Corvus macrorhynchos osai, the Japanese White-eye Zosterops japonicus loochooensis, the Brown-eared Bulbul Hypsipetes amaurotis stejnegeri, and the Emerald Dove Chalcophaps indica yamashinai, to visit and eat the seeds. These endemic sub-species of birds are regarded as important seed dispersers of this pioneer tree.