Should I install an owl box?
This is a frequent question asked of Santa Barbara Audubon Society (SBAS) by community members. It is important to clarify that for our area we are talking about boxes for Barn Owls since they are, in most years, annual residents and are voracious consumers of rodents.
Every proposed Barn Owl box installation differs in the expected results and the conditions at the site. Whether the intent is to resolve a rodent problem or to simply enjoy the presence of an owl, such installations require a background understanding of the circumstances in which boxes are to be introduced. Several factors should be considered before installing a Barn Owl box:
Barn Owls have ample nesting and roosting opportunities in Goleta and Santa Barbara. This is due in large measure to the abundance of our palm trees which provide suitable sites for nesting and roosting for this species. Therefore, the addition of a nest box may not necessarily attract a Barn Owl. They may be present in your immediate neighborhood already.
- Are Great Horned Owls present in the general area in which a Barn Owl box is being considered? Encouragement of a Barn Owl to an area with Great Horned Owls may prove to be detrimental to Barn Owls. Great Horned Owls are aggressive predators on Barn Owls, especially when Great Horned Owl chicks are demanding food. Great Horned Owls will not tolerate Barn Owls competing with them for precious near-to-their-nest food sources.
- Are there mortality risk factors present in the location you are considering? For example, placing Barn Owl boxes near roads and highways should be avoided. Barn Owls are attracted to the road edges and highways medians as hunting locales. This often leads to high death rates from collisions with vehicles.
- Are there resources that Barn Owls might hunt that you, as a steward of the area, wish to protect? Does introduction of a Barn Owl box conflict with sound wildlife management practices or your own wildlife management goals or those of your neighbors?
- How easy will it be to maintain the Barn Owl box after the installation? These boxes can become beehives or rat houses immediately and in subsequent years. Since maintenance is required, will you be able to clean them out annually?
The journal, Bird Conservation International, published a paper in 2007 entitled Exterior nest-boxes may negatively affect Barn Owl (Tyto alba) survival: an ecological trap. The abstract of this paper is available at this link.
SBAS appreciates your thoughtful consideration of the points noted above before you decide to install a Barn Owl box.