Fredrik Christiansen/Functional Ecology
Every winter, hundreds of humpback whales migrate long distances from their high latitude feeding grounds in the Arctic and Antarctic to warmer tropical regions to breed and give birth. The newborn calves, which consume over 52 gallons of milk on a daily basis, have only a few months to pack on the body fat needed to survive the long trek back to cooler waters in summer. How the babies signal hunger and avoid predators during these formative months has always been a mystery to scientists.