Nesting season has already begun for a few species and is rapidly approaching for others, so now is a good time to put out nesting boxes (bird houses) for the species that use them. Placing nesting boxes in your yard is a great way to help bird species that normally nest in old woodpecker holes or cavities. Since most cavities are excavated in dead, dying or diseased trees, there is a shortage of habitat supporting cavity nesters in urban neighborhoods. This is because, for the most part, foliage is kept well groomed and dead trees are considered unsightly or a liability, and thus removed.
Cavity nesting birds include woodpeckers, wrens, nuthatches, titmice, bluebirds, some flycatchers, swallows and owls.
You really have the ability to broaden bird diversity in your yards and neighborhoods by offering these cavity nesters an appropriate shelter.
It is very important that these size of the nesting box and its entrance hole conform to species-specific dimensions and that the birdhouses are properly mounted at appropriate heights in suitable habitats.
Offer soft nesting materials
Many species of birds will utilize soft nesting material in their nest designs. Goldfinches, bushtits, hummingbirds and orioles are a few of those species, but it is the hummingbirds that are making use of it now. Watch where they go with it! After a few trips, you should have an idea where the nest is. If you are lucky enough to find one, do give mom her space-this way she never feels her nest is threatened. If you want to put your own material out for them, never use dryer lint, because lint fibers are very short and will not structurally hold up in some situations.
In case you are looking for birdhouses, they are available here.
Source of the bird information, is a most wonderful resource: wildwingsla.com