Climbing Behavior of Apodemus argenteus and Apodemus speciosus (Rodentia : Muridae)

Abstract

To compare the climbing ability of two species of Apodemus, A. argenteus and A. speciosus, 1) vertical bar climbing test, 2) horizontal bar walking test and 3) gap crossing test were conducted in their natural habitat. In tests 1) and 2), A. argenteus surpassed A. speciosus, while in 3) no qualitative difference was observed. A. argenteus climbed vertical bars of all diameters easily and actively, while A. speciosus refused to climb almost any sort of bar. In walking on a horizontal bar, A. speciosusu lost its balance more frequently and was more awkward and slower in movement than A. argenteus. These facts seemed to show that there is a clear-cut difference in arboreal tendencies between the two species of Apodemus : this might serve to reduce competition between them in areas of sympatry.