Conservationists build 400-tonne structure in Surrey, southern England, to tempt migrating sand martins back to nature reserve after 25 years.
A giant “sandcastle” has been constructed to encourage sand martins to nest at a nature reserve, says Surrey Wildlife Trust. The 400-tonne installation was built by professional sand sculptors who used a “giant bucket mould” made from wooden boards, as well as the help of diggers and dumper trucks.
Sand martins visit the nature reserve when they migrate from sub-Saharan Africa each year, arriving from mid-March to feed until September, but they have not nested there for 25 years.
The 20m long construction will allow hundreds of the tiny 12cm birds to nest and raise their young at the reserve.
It's hoped the scale of the scheme will enable the sociable birds to roost together, and that the curved vertical face of the sandbank will allow them to peep out of the nest holes to find mates.
“In the UK, the natural nesting inland habitat along riverbanks has decreased as rivers pass through more urbanised areas and under roads, and quarrying has ceased,” says James Herd, project manager at Surrey Wildlife Trust. “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 structure, he added, would give the sand martins the chance to return to nest safely year after year at Spynes Mere, a part of the Nutfield Marshes that was originally created from a restored sand extraction site.