Habitat variables of the Japanese squirrel identified by regression tree model

Abstract

Habitat variables of the Japanese squirrel, Sciurus lis Temminck, were analyzed by the regression tree method based on radio-tracking data. The results suggest that the squirrels tended to use the sites with more walnut trees from July to December, and more evergreen trees in middle layer from January to June for feeding. For nest sites, they tend to use sites with more evergreen trees in the upper layer, preferably having DBH (diameter at breast height) of at least 30 cm. These results are consistent with observations in previous field studies.