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.
“We know next to nothing about the early life stages of whales in the wild, but they are crucial for the calves’ survival during the long migration to their feeding grounds,” says study lead author Simone Videsen of the University of Aarhus, Denmark. "These early life stages of wild whales are so elusive because they're an aquatic animal. We can't follow them around all the time to see what they're doing."