Fate of walnut seeds,Juglans airanthifolia,hoarded by Japanese squirrels,Sciurus lis

Walnut seeds (Juglans ailanthiforia Carr.) hoarded by Japanese squirrels (Sciurus lis Temminck) were tracked using miniature radio transmitters. A total of 100 seeds with transmitters were provided on the feeding stands in the walnut forest from September to December, 1992. Squirrels ate 35 seeds without hoarding, and 60 were scatter-hoarded. Five seeds were eaten by wood mice (Apodemus speciosus Temminck). The distance from the feeding stand to cache sites ranged from 1 to 62 m with the mean 18 m. Of 60 hoarded seeds, 38 were retrieved by squirrels later, but 15 were stolen by wood mice. After all, 7 seeds were not retrieved until May 1993.