Abstract
We observed the foraging behavior of birds feeding on a common pioneer tree species, Zanthoxylum ailanthoides, in countryside forest on a warm-temperate zone of Shikoku in order to study the feature of seed dispersal. Two bird species, those were Japanese White-eye Zosterops japonicus and Daurian Redstart Phoenicurus auroreus, were observed foraging seeds of Za. ailanthoides among 10 frugivorous bird species observed on the site. We concluded that Zo. japonicus was the most effective seed dispersal agent of Za. ailanthoides because of its high frequency of seed foraging. The number of fruit bunches on observed Za. ailanthoides decreased from late November to December, whereas most fruits opened their pericarp in December. Also Zo. japonicus visited frequently to the observed tree to forage seeds in early and middle December.
