@natgeo: New drone footage from the Head of Bight, South Australia, shows a southern right whale mother resting belly-up, pectoral fins stretched into the air before slowly rotating to take a breath, then swiveling upside down again. They're the only large whale species documented doing this, but what's the purpose of this unusual behavior? Researchers now theorize it may be tied to energy conservation while nursing their calves, though there's another theory floating around. Learn more about this unusual behavior at the 🔗 in bio.