Complex sentence: Ussuri brown bears, along with the smaller Asian black bears constitute up to 40.7% of the Siberian tiger's diet, and brown bears alone constitute up to 18.5% of their diet depending on the locations.
Split into simpler sentences: Ussuri brown bears, along with the smaller Asian black bears constitute up to 40.7% of the Siberian tiger's diet. Brown bears alone constitute up to 18.5% of their diet depending on the locations.