Infanticide or predation? Cannibalism by a brown bear in Hokkaido, Japan

Abstract: Cannibalism in brown bears (Ursus arctos) is infrequently reported worldwide. This study reports evidence of brown bear cannibalism in northern Hokkaido, Japan. In April 2017, we found a bear scat containing the body parts of a bear cub. We also found a series of tracks (width of the front track: 16 cm) of an adult male bear near the scat, which were likely associated with the excrement. The scat was found at the end of a long hibernation season and the beginning of mating season of brown bears in Hokkaido. The timing suggests that the cannibalism event was a consequence of infanticide by a male bear as part of mating strategy, namely, sexually selected infanticide.