Help Burrowing Owls

If you’re a landowner in the Sacramento County area, why not build your own nesting site for this charming little owl?

Selecting the Right Site

Choose a site for your artificial nest mound using the following criteria and your own common sense:

• Good drainage, generally on a slight rise in the landscape. Water must not be allowed to drain toward the nest structure.
• Ample nearby foraging opportunities, generally 10-20 acres of short grass habitat for each nesting pair of owls. Grazed cattle pastures, roadsides, annual grasslands and any other short vegetation habitat that contains a supply of insects and small vertebrates can be used.
• Away from disruptive human activities such as construction, uncontrolled public access, fast moving vehicles and other activities that might disrupt the owls daytime and nocturnal behavior.
• If you build it they will come. These owls move around and may locate the new homes from some distance. However, you can increase your chances by locating them as near to an existing owl population as possible. You may want to build two mounds in different locations allowing the owls to choose the one that best meets their needs.

Obtaining Soil for Building the Mound

After choosing a site, soil to construct the mound may be either imported into the area or scraped from the surrounding area. If you scrape the soil into a pile, take care not to negate the natural drainage. Approximately five to ten cubic yards of soil are required to construct a single chamber mound, ten to fifteen yards for a double chamber mound.

The chambers and tubes can also be placed directly into the ground, without the need to import soil. In this case, it is still best to scrape a small mound over the chamber. Here, it is even more critical to pay attention to possible drainage problems.

Providing Proper Drainage

If your site has good drainage, the chamber and connecting pipes may be laid out on the ground surface and then dirt carefully piled on top of them. If drainage is a problem, build the mound first, then dig trenches for the chamber and pipes. This will ensure the chamber is above existing grade.

Nest chambers may be constructed of concrete or plastic irrigation valve boxes, such as the Christy concrete valve box #B-12, obtainable at landscape supply, home supply, and many general hardware stores. Concrete material is preferable as it provides the greatest thermal protection. Ideally, the inside dimensions of the chamber should be between 144 and 300 square inches of floor space. Mark or sketch the chamber location so that you can locate the buried lid in the future, if the need should arise. Place some form of perch (snag or wood post) near the mound.

Configuring the Tunnel Pipes

The four-inch corrugated pipe must be at least eight feet long and set to make a 90-degree bend. This is important, as this configuration will minimize light inside the nesting chamber. Two pipes are necessary to allow proper ventilation and escape routes should a predator enter the chamber. Pipes greater than four inches allow easy entry for potential nest predators and should not be used. Once the pipe is in place, the ends should be inserted into concrete cinder blocks to anchor them and discourage digging attempts by coyotes and feral dogs.

Contact Us

For more information on burrowing owl protection, contact:

Bryan Young
Bufferlands Manager
Email: youngb@sacsewer.com