Sparrows in Summer
Sparrows are great thieves; they are larger, stronger birds than house-martins, and so are able to drive them from their nests by the simple method of taking possesion.
They cram the delicarely built cups with straw and feathers, and such rubbish that sparrows love, until the martins give up and have to go away to build another nest.
Sometimes even the second and third house-martin nests are also stolen.
Sparrows can be discouraged by placing a curtain of weighted strings in front of the nest.
Sparrows find it difficult to fly up at a steep angle to the nest, but martins do so easily.
The strings should be about 230 mm long, 65 mm apart and no nearer than 150 mm to the nest hole.
The strings should all be the same length to prevent tangling.
They can be fixed with nails or drawing pins and weighted with steel nuts or plasticine.
This curtain may be erected before the martins arrive but should only be put up during nest building if sparrows attempt to take over.