For most people, assessing a bear’s weight or fur color isn’t a top priority during an unexpected encounter in the woods. This is especially true given a bear’s often dramatic, seasonal weight fluctuations, as well as how physically different they may look pre- and post-hibernation. PoseSwin was trained on over 72,000 photos of 109 different brown bears taken by APU researcher Beth Rosenberg between 2017 and 2022. She and her colleagues then relied on their existing knowledge of brown bear physiology to determine the handful of anatomical details that remain relatively constant over the animal’s life. Early benchmark tests indicate it’s also incredibly accurate when trained on macaques, suggesting it could soon expand to handle many other species.