Even though they are large animals, humpback whales do have natural predators. Transient orca whales and some species of sharks prey on humpback whales, usually targeting young whales, or adults that are sick or in distress. 'Rake marks' are the name given to the parallel scars often seen on whale flukes. Scientists wondered what caused these markings and discovered that they have the same spacing as orca teeth. Many adult humpbacks have rake mark scars from a close encounter with a predator when they were younger.