Best friends forever: a sea otter mum and her pup have an incredibly close bond. She’ll teach her youngster how to hunt and how to use a rock to crack open clams. Groups of dozing sea otters sometimes hold hands while they nap so they don’t float away in the currents. A hundred years ago sea otter populations crashed from a million to a mere 2,000 after intensive hunting on the Pacific coasts. They are still endangered today
Photograph: Michael Gore/FLPA