Humpback Whale Tail Flukes. Humpback whales have very unique tail flukes, the undersides of each and every humpback whales tail fluke is unique to each individual and that is how they are identified. Researchers employ volunteers to photograph the undersides of their tail flukes to I.D. each individual. The markings can range from all white to all black and everything in between. Even scarring from Orca encounters to entanglement are identifying clues that help researchers. The flukes can reach 13 feet across from fluke to fluke.