Along Australia's southern shores, southern right whale mothers exhibit a rare behavior: resting upside-down in shallow waters. Researchers have discovered this is a clever strategy to conserve energy and regulate body temperature during the critical period of nursing their calves.
- Only mothers and pregnant females rest upside-down
- Behavior helps manage energy and milk feeding
- Exposes skin to cool sea breeze for temperature control
What happened
Researchers from the University of Western Australia and Aarhus University used drones to observe southern right whales along the Great Australian Bight. They discovered that about 25% of mothers with calves, and one late-pregnant female, exhibited an unusual behavior of resting upside-down near the surface, a behavior not seen in other whale groups.
This resting position accounted for roughly 19% of the mothers' observed time. The upside-down posture appears to be a deliberate action by the whales, related specifically to their reproductive and energetic needs during the calving season when they are not feeding and rely on stored energy reserves.
Why it feels good
Upside-down resting likely helps mother whales manage energy by limiting calf access to milk when the mother needs a break, balancing the demands of feeding her calf while conserving her own reserves. This supports their survival over long migrations without feeding.
Additionally, unlike whales with dorsal fins that help dissipate heat, southern right whales lack this feature. By lying belly-up, they expose more skin to ocean breeze, enhancing heat loss and helping prevent overheating — crucial for maintaining body temperature during intense periods of nursing and recovery.
What to enjoy or watch next
Spotting these gentle giants resting upside-down is a rare treat for whale watchers along Australia's southern coast during the breeding season. Observing this behavior offers a unique window into their complex life cycle and maternal care strategies.
Future research and conservation efforts can benefit from understanding this behavior, especially as these whales remain vulnerable to human threats. Protecting their resting and breeding habitats ensures southern right whale populations have the space and safety to continue thriving.