But they are vulnerable to flash floods, which hit the Avon, the Severn and many other rivers last summer.

As water levels rose, the nests and weak young birds were swept away. 

The rising water also made it harder for the adults to hunt because the rivers were too deep to dive into. 

Royal Society for the Protection of Birds spokesman Andre Farrar said: “When a river floods it can be devastating for a family of kingfishers. 

“With more spring floods happening, the worry is that they are not going to be able to produce enough young.”

Kingfishers declined until the mid- 1980s because of river pollution. But as the waterways were cleaned up, numbers rose.

And today there are thought to be up to 5,500 breeding pairs in Britain.

So watch out for a flash of electric blue and orange flying low, or sometimes hovering, over a river near you – it will herald the return of the king.