Meet the Giant Sandcastle Built for Britain’s Smallest Swallows

Conservationists in Surrey, South East England, have completed a 400-ton giant sandcastle to tempt migrating sand martins, also called bank swallows, back to their nature reserve after 25 years, and to boost their dwindling numbers. This remarkable structure is the handywork of professional sand sculptors determined to offer these tiny brown and white fork-tailed songbirds an amazing nesting experience they can’t resist.

Why the need to create a home for these feathered friends, first recorded in the UK in Anglo Saxon times? James Herd, project manager at Surrey Wildlife Trust, the conservation organization behind this initiative explains: “Sand martin numbers have plummeted twice in the last fifty years as a result of droughts in their wintering grounds in Africa.  In the UK, the natural nesting inland habitat along river banks has decreased as rivers pass through more urbanized areas and under roads, and quarrying has ceased… So creating this nest bank is important to protect them against the boom and bust nature of their nesting sites and give more security for the population to expand.”

The @SurreyWT has unveiled a giant 20-metre wide sandcastle for sand martins, tiny 12 centimetre brown and white birds, to welcome them back from Africa to nest at a Surrey nature reserve https://t.co/BXcC7GIm1W pic.twitter.com/sRiXnlxSO2

— CJS News (@CountrysideNews) March 29, 2021

“The new ‘des res’ is ready for sand martins to move in, leaving nature and the sand martins to do the work of sculpting hundreds of nesting burrows,” sand sculptor, Jamie Wardley, told The Guardian. Mr. Wardley is director of Sand in Your Eye, a company creating inspirational and fun artwork that in its own words ”will make you laugh and think, shout out in amazement, and perhaps even shed a tear.”

While most sandcastles on the beach are built using buckets and spades, this giant version, was created with the help of diggers and dumper trucks and a “giant bucket mold” made out of wooden boards. The naturally-occurring clay found at the site will help the sand to hold its shape.

Sand martins use their tiny clawed feet to dig burrows of up to one yard in length, into vertical surfaces. They create a small chamber at the end, where between four to eight eggs are laid on vegetation and feathers that have been carefully gathered.

This huge, new sand installation has been specially designed with a curved, vertical face that is 22 yards long, so these tiny five-inch birds, the smallest of Britain’s swallow and martin family, can peep out of nest holes to find mates and rear their next brood of chicks.

If you’re wondering why a structure of this size is needed, Surrey Wildlife Trust explains why creatures this small can benefit from the large size of the sandcastle structure. They are sociable birds that roost together in large numbers and so the scale of the sand bank is as important as its sustainability.

The plan is that the giant sandcastle is here to stay.  Mr. Herd of the Surrey Wildlife Trist said in a response to a tweet, that the structure is expected to last in its current form for five to seven years, after which it will re-use the sand to rebuild it, enabling it to last for decades.  The hope is that at the location in Spynes Mere in Surrey, the sand martins can return to nest safely in the sand bank year after year.