I'm spending a couple of weeks in a wonderful corner of Dorset: Hooke Park. As you can imagine, with the summer in full swing there's bird singing everywhere including inside my friend's house, where two lovely swallows decided to nest.
In this forest there are quite a few places for birds to nest, nonetheless the forester has placed bird and bat boxes across the forest. Bird boxes (nestboxes) are excellent substitutes for the holes found in old trees. In woodlands such as this one, and in many parks and gardens there may be plenty of food for small birds but nowhere for hole-nesting birds to nest.
We know that over 60 species have used bird boxes. You will usually find blue, great and coal tits, nuthatches, house and tree sparrows, starlings, spotted and pied flycatchers, robins, house martins, kestrels and tawny owls. Different species can be attracted depending on the type of box, the size of it's opening, and location that it's placed.
One thing to keep in mind when choosing your bird box is that there are some birds that need more support than others. For example blue and great tits have prospered, while house sparrows and starlings have declined. If you want to provide a nest box, try if possible, to target those birds that genuinely need help.