The kingfisher: British rivers' living jewel and a sign of cleaner water

Spend long enough beside a quiet river and you may catch it: a sudden streak of electric blue skimming low over the water, gone almost before your eye can follow. For many people that dazzling flash is the only glimpse they ever get of the kingfisher, one of the most colourful and best loved birds in Britain.

A jewel on the riverbank

Up close, the kingfisher is a small, dumpy bird with a large head, a long dagger of a bill and a short tail. Its back glows an intense blue and turquoise, while its underparts are a warm chestnut orange. For all these brilliant colours, a perched kingfisher can sit surprisingly still and unnoticed above the water.

It is a patient and deadly fisher. From a low branch or reed it watches the water intently, then plunges headfirst in a blur, seizing a small fish in its bill. Back on its perch it beats the catch against the branch before swallowing it head first, and a single bird may take many small fish in a day.

Tied to clean, living rivers

The kingfisher is bound to clean, clear and gently flowing water. It hunts by sight, so it needs unpolluted rivers where it can spot small fish such as minnows and sticklebacks below the surface. Slow streams, canals and lakes fringed with good perches and earthen banks are its classic haunts across the country.

That dependence makes the bird a living gauge of a river's health. Where kingfishers thrive, the water is usually clean and full of life. Their numbers fell across Britain from the 1970s onward as pollution and habitat loss took their toll, though in recent years cleaner rivers have helped them recover in many places.

Tunnels in the bank

When it comes to nesting, the kingfisher becomes a miner. The pair dig a tunnel into a bare, soft earth bank beside the water, at the end of which the female lays her glossy white eggs. Breeding gets under way in early spring, and a successful pair may raise two or even three broods in a single season.

Both parents then work tirelessly to ferry a constant stream of small fish to their hungry young. This way of life ties the birds closely to natural riverbanks, and where rivers are straightened, hardened or stripped of their earthy edges, the kingfisher loses the very places it needs to breed.

Numbers and protection

The kingfisher is not a common sight, and the whole of the United Kingdom holds only a few thousand breeding pairs, with estimates ranging from roughly three thousand eight hundred to six thousand four hundred. It is amber listed and receives special legal protection under our wildlife law.

Its fortunes can also swing sharply from year to year. Because it feeds in shallow water, a hard winter that freezes rivers and ponds can be deadly, killing many birds in a single cold spell. After such losses the population usually rebuilds over the following milder years, so numbers rise and fall.

A barometer of our rivers

In this sense the kingfisher is a small, brilliant barometer of the state of our fresh waters. Cleaner rivers and healthier fish stocks lift its numbers, while pollution, habitat loss and harsh winters push them back down again. Its shining presence is a hopeful sign that a river is alive and doing well.

Protecting the kingfisher therefore means caring for whole river systems. Keeping water clean, leaving natural earth banks in place and restoring the plants and fish of our streams help not only this one jewel of a bird, but the countless other creatures that quietly share its watery home.

Worth looking for

The next time you walk beside a river, it is worth pausing and watching the water for a while. That electric flash of blue, when it finally comes, feels like a small reward for patience. Keeping our rivers clean and alive is what will ensure the kingfisher keeps lighting them up for many years to come.