Sand martins nest in burrows they dig in rocks and hills. Areas rich in water, in particular canals and streams, are their natural habitat. Due to canalization and other water management, many of the natural breeding grounds disappeared. At Montrose Basin in Scotland, volunteers have therefore given these birds a helping hand by building a sand martin wall. This consists of two walls of hollow concrete blocks that are anchored to each other with an auxiliary structure. Sand was placed between the walls, which are approximately two meters apart. The coarsecompacted sand was covered with soil and vegetation. The insects attracted to the flowers and plants are now a food source for the sand martins. On both sides, holes were made into the wall, all of them numbered to facilitate systematic observation. The birds use their beaks to bore tunnels of up to a metre deep in the sand.
-Montrose (UK) 2002
-Scottish Wildlife Trust, Montrose Basin Local Nature Reserve