House martins have declined 44% since 1995 as modern building materials and renovation remove traditional nesting sites, with artificial nest cups providing a direct welfare solution.
Loss of nesting sites forces house martins to attempt nesting on unsuitable surfaces or abandon house nesting entirely. Birds returning to sites blocked by renovation face the welfare cost of failed territory establishment after a long-distance migration. Installing artificial nest cups directly addresses this welfare problem by providing the surface conditions needed for nest construction.