If a rainbow stands guard over a pot of gold, what treasures does this ethereal archway hide?

Fogbow, mistbow, white rainbow – a sailor might call it a sea-dog. It is created by light refracting through mist, and there was no shortage of that in Norfolk yesterday, as if the clouds had wearied of the heavens and slumped onto the land to wait out the dying embers of the year.

Fogbows are uncommon; I’ve never seen one before. And in a twist of magic, it did have white gold at its feet – but of fur, not precious stones. The seal haul-out beach that I last visited in October is now a nursery for over a thousand babies.

Many terrestrial carnivores give birth to helpless young and nurse them for months, if not years, but grey seals have no such leisurely schedules. After just three weeks of intensive feeding on milk that is over 50% fat (compared to 4.5% in human breast milk and 6% in fox milk), they are done and weaned.

This little one tried to explore the beach by itself, and its mother lumbered after it, putting the breaks on its travels.

But they leave her soon enough, living in the dunes for a week or two, their white fur taking on the speckled hues of the adults.

Their mothers, meanwhile, mate with the bulls. Eleven months from now, new pups will be born.

Maybe the fogbow will return to greet them.