Footage from a drone flying off the coast of New Zealand may have captured a rare natural sight—a blue whale nursing her calf.Because the footage is aerial, marine ecologist and Oregon State University professor Leigh Torres can't say for sure if the footage she captured definitely shows nursing behavior, but the calf's alternating between coming up for air and swimming underneath its mother in the same spot strongly suggests it. If verified, this would be the first known footage of a blue whale nursing.As a species, the blue whale is a particularly mysterious creature, and its anatomy suggests that nursing would be a complicated process. For aquadynamic purposes, the mother's nipples are covered by folds of skin, and scientists still aren't sure how the mother selectively uncovers her nipples and delivers the milk (whales don't have lips, so they can't suckle).And although calves must consume 50 gallons of milk per day, gaining 38,000 pounds in about six months of nursing, humans have never managed to film the process.Torres says she saw five pairs of mothers and calves in a small area during her New Zealand trip, which gives her hope that the population is recovering after being hunted nearly to extinction.When Torres and her crew launched the drone from their boat, they had no idea they'd spotted a nursing calf. "But from the overhead perspective we could clearly see this coordinated behavior between mother and calf," she told National Geographic. "It was beautiful to see."