A Bear Walking, ca. 1482?85, silverpoint on light buff prepared paper, 4 1/16 x 5 1/4 in. (10. 3 x 13. 3 cm), Drawings, Leonardo da Vinci (Italian, Vinci 1452?1519 Amboise), Leonardo da Vinci's abundant drawings and notebooks record his keen and tireless observation of all aspects of the natural world. He probably drew this study from life and his anatomical understanding of the animal may have been aided by his dissections of bears