Fur Seals’ Hearts Suddenly Spike Hours After Returning to Land

A study of Cape and Australian fur seals found delayed heart-rate spikes 6 to 8 hours after they came ashore.

Researchers tracked repeated at-sea and on-land cycles and saw that harder activity on land was linked to more intense activity at sea.

The results suggest diving recovery is not limited to the surface and can continue long after seals leave the ocean.

This challenges the idea that the main physiological cost of foraging ends when marine mammals return to land or rest.