Mysterious Blue Whale Behavior Likely Filmed for First Time

Watch: This may be the first footage of a blue whale "heat run." Blue whales are the largest animals on Earth, but we know surprisingly little about their complex social interactions--and they've rarely been recorded on camera. But new footage filmed off the coast of Sri Lanka by pro whale photographer Patrick Dykstra, in conjunction with blue whale scientist Howard Martenstyn, may be a first. Their video shows what they believe is the first known clip of a blue whale "heat run." Heat runs have been well documented in humpback whales, but no known footage exists of the behavior in blue whales (or at least that Dykstra or National Geographic could find).