In the five years after the millenium the number of barn swallows and common house martins reduced to half. To stop this process, we have to protect the present settlements that has been used for years, and also have to improve them. These artificial nests can help that project.
The artificial nests can be used to make new colonies, and to improve present colonies as well, and broadening used ones is much more beneficial because there is a bigger chance that they are going to nest in it.
When should you put out the artificial nest?
Swallows are breeding two times a year: the first starts in April or May, the second in June or July. According to this, if you put out the nest from early spring until the middle of summer, they can use it to breed the same year. But it isn't a problem if you put it out an other time, because they can settle the next breeding season.
On the left you can see an artificial nest for common house martin, on the left for barn swallow. These has to be placed like the natural nests of these birds: for common house martin you should put it up to the ceiling, for the barn swallow, put it 8-10 cm below the ceiling.