The Large Japanese Field Mouse (Apodemus speciosus) as a Consumer and Potential Disperser of Seeds of the Neurotoxic Japanese Star Anise (Illicium anisatum)

Abstract. The small Japanese field mouse Apodemus argenteus is known to disperse the highly toxic seeds of the Japanese star anise Illicium anisatum (Schisandraceae); however, whether the large Japanese field mouse A. speciosus does so remains unexplored. Seeds of I. anisatum were placed in mesh cages with openings sized only for small rodents and monitored at two forest sites in Tsukuba, Ibaraki Prefecture, Japan, in autumn 2018. Any animals approaching or entering the cages were recorded by automated cameras with infrared motion sensors. Only A. speciosus was recorded entering the cages. At both sites, some seeds were consumed inside the cages or transported outside them. These results show that A. speciosus interacts with seeds of I. anisatum and is a potential agent of seed dispersal. Further study is needed to determine whether it can tolerate anisatin, the main neurotoxin in I. anisatum, and the possible tolerance mechanism.