Thank you for your interest in owl boxes. Owls do not build their own nests. Most owls simply use the old nests of hawks, ravens, and other birds. In Marin we have several local species that are cavity nesters: including Barn Owls, Western Screech Owls, and Saw-whet Owls. North America's smallest falcon, the American Kestrel, is also a cavity nester. These species will readily use artificial cavities in the form of nest boxes.
Barn Owls are generally found in or near open fields and meadows, but sometimes nest quite close to homes in backyards or parks. Western Screech Owls are generally found in oak woodlands, especially near streams or creeks. Great Horned Owls (they are the ones that hoot!) do not use nest boxes - they take over previously constructed nests of hawks or ravens. Examples of ideal Barn Owl habitat can be seen in Nicasio and West Marin, and Petaluma - agricultural areas. Also along Highway 37 in Sonoma, and any of Marin's protected open spaces that feature oak savannahs and large open areas. Western Screech Owls might also frequent such areas, but their ideal habitat is woodlands, especially near streams. They too have been found nesting quite close to human habitations - even in attics and under eaves. A good nesting cavity is hard to find! Old and dead trees provide homes for many species of birds and should be left standing whenever possible.
There are many owl nest boxes available for purchase, however we feel our design is the most beneficial for the protection of the owls for several reasons: the hole size is specific for Barn Owls and too small for Great Horned Owls to enter and prey on Barn Owls or their chicks, the box has a convenient clean-out flap, it is treated with a non-toxic, water-based stain or paint that can extend the life of the box up to 10 years, there are no perches on our boxes - perches are helpful to predators, the Barn Owls don't need them, finally by purchasing a Hungry Owl Box you are supporting our non-profit, educational work. The decision to put up an owl box should not be made lightly, and should be based on an evaluation of whether you actually have good habitat for any of the cavity nesting owl species.