Applicability of the point-frame method for food habit analysis for various mammals

The point-frame method was adopted to analyze the food habits of the sika deer and three omnivorous mammals of Order Carnivora: the raccoon dog, the masked palm civet, and the Japanese marten. Food contents were grouped into 20 categories and 200 points were counted, taking 3 hours for the deer and 30–60 minutes for carnivorans. Only 6 categories were found in the deer foods whereas 11 to 14 categories appeared in the carnivorans’ foods. The numbers of categories per sample were about 4 for the deer and the palm civet, about 3 for the raccoon dog, and 2 or 3 for the Japanese marten. Since the deer is a ruminant, rumen contents were well homogenized and samples contained most of the total categories; whereas since carnivorans have wider food habits and simpler stomachs, they also have greater differences in the number of categories between the total and each sample. During winter, animal materials decreased and fruits increased. Similarity was smaller between sika deer and other carnivorans and greater among the latter. We confirmed that the point-frame method is widely adoptable from ungulates to carnivorans and effective to compare the food compositions, diversities, and similarities.