The artificial nest cups are more robust than the endangered birds' own mud creations.

Homeowners, schools and businesses are being offered the chance to install artificial nests to help reverse the decline in house martin numbers.

The distinctive dark blue and white birds, which migrate from Africa each spring, are on the UK’s Red List of endangered bird species.

The Hampshire House Martins Project is offering free so-called nest cups, which save the birds time and energy compared to building their own mud nests.