Martha Kearney explores the shifting sands of Gibraltar Point on the Lincolnshire coast, where wardens go to extraordinary lengths to protect shore-nesting birds from habitat loss caused by beach erosion. They build wooden platforms for the nests of little terns and cages to protect the nests of ringed plover, as well as mounting overnight patrols to keep predators away. The beach sand is replenished every year to protect the coastal population from flooding, with 400,000 cubic metres beng added by offshore dredgers
