Take a blob of mud, mix with grass or straw, and build! A rounded shape works well. Add an interior lining of feathers, moss and other soft vegetable matter et voilà! You have the perfect nest in which to raise your brood of House martins.
There’s a street near my home, where the houses have the perfect architectural feature for House martin nests. Just below the eaves and above the first floor windows there are small abutments, the tops of which provide perfect little ledges where the House martins can prop their mud-pellet homes. On a recent walk past I counted twelve nests, though not all appeared to be occupied.
Of course, House martins (Delichon urbicum) would once have built their nests on cliffs – and some still do – but many have now become urban dwellers. The little colony in my local street is not uncommon as they prefer to dwell in groups, occasionally in large groups of several hundred nests though small groups of five to ten are more usual. Old nests are refurbished by returning birds, though not necessarily the original builders, and new nests are built where there’s space available, taking only one to two weeks to construct.
Though most humans live happily alongside their avian visitors, some get annoyed by their noise and the mess they create. Luckily, House martins and their nests are protected under the Wildlife and Countryside Act 1981 so it’s illegal to remove an active nest. I would feel privileged indeed to have a nest of these gorgeous little birds attached to my home.