The bolt of a blue as a kingfisher flies past is one of the joys of walking along a riverbank. I've studied these jewel-like birds from hides for many years.
By now kingfishers have finished their courtship feeding, a ritual which involves the male catching a fish and presenting it to the female to prove he can provide for her.
If she accepts the fish, she's accepted the male and mating commences.
To avoid predators and the possibility of flooding, the pair selects the steepest bank in their territory to dig out a tunnel to nest in. They often use a bank they've used in the past.
The hole is mainly dug out by the male while the female checks it for size and gives her mate encouraging calls and the occasional helping hand.
Starting a new hole on a vertical incline is no mean feat. He flies at the bank with an excited piping call, hovering and pecking at the soil.
Having made an indentation, he will find any support he can – I have seen one cling onto an exposed root– and peck away like a woodpecker to make the entrance hole.
If the digging is good, the hole is excavated up to three feet long. If the soil is hard, it's shorter. The layout is always the same, sloping upwards at a slight gradient and housing a nesting chamber at the end.
It can be exhausting work. The male takes a break every so often and sits beside his mate. They exchange quiet ‘cheeps' and bob along to the tune. The male shows an exaggerated upright stance with drooping wings and an angular profile.
Sometimes he will catch another fish for her, as if to check she's still on side, which he presents head first to make it easier to swallow. She accepts with quivering wings.
In April, five to seven pure white eggs are laid. These are mainly incubated by the female and hatch in the nesting chamber 19-20 days later.
With all these hungry mouths to feed, things start to get busy for the parents now.
The male does the majority of the fishing in the early days, while the female tends to her young.
Amazingly, these tiny chicks swallow fish whole. If I see a kingfisher with minuscule fish in his beak, I know that there are small chicks in the nest.
The hungry brood devour up to 100 fish a day and put on weight rapidly in the first week.
Soon they are tackling larger fish such as minnows, sticklebacks and trout fry. Now the female joins in with fishing duties.
When the chicks are three weeks old the reason for the upward sloping hole becomes clear. A smelly fishy residue seeps out of the hole and away from the nesting young.
The chicks are now well feathered and look like dull-coloured mini adults with a white tip to their bills.
Just a few days later, encouraged by their parents, this first brood leaves the nest to fledge, usually during the last two weeks of May.
This is a tense time for both and involves a lot of anxious calling. The parents lead the chicks to a safe place, usually a willow tree hanging over the water, and within hours they practice fishing, plunging down fearlessly like arrows onto a passing leaf or twig.
Whilst watching this once my heart jumped as I saw one do a belly flop and floated off downstream. Luckily it found safety on a semi-submerged twig.
There is good reason for this early target practice. Within three days these vulnerable birds are left to fend for themselves. Adult kingfishers have two to three broods a year and there is no time to waste.
Sometimes they use the same hole for the second brood, after spring cleaning, but often another hole is dug nearby.
One year, the female's urge to breed was so strong she was already sat on a full clutch of eggs whilst just three metres away in another hole her two-and-a-half-week old chicks were yet to fledge, which the male was tending to.
I find the different breeding habits of birds interesting. Kingfishers rely on sheer numbers. Some pairs may produce 15 to 20 chicks in a year. But their parental duties don't extend much beyond getting their young to fledge. Mortality is very high, 75% are thought to die in the first year.
In comparison, larger birds like tawny owls, devote all summer to getting just two or three chicks reared, feeding and looking after them well into autumn.
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Wildlife Diary -
