Although the eggs had not survived, the success of the duck box for a nesting area was very clear. Wood ducks, common goldeneyes, hooded mergansers, common mergansers and buffleheads are all cavity nesting ducks. These ducks will use a constructed nesting box. Kestrels, tree swallows, great-crested flycatchers or screech owls are also cavity nesting birds. Nesting sites for these birds are limited in number. When they find a good nesting site, there is a very good chance they’ll return in following years.