Date of this Version
Burrowing owls (Speotyto cunicularia) were monitored over a four year period at Naval Air Station North Island, a developed area at the north end of San Diego Bay, California. Protection of the nest burrows and a burrow marking program were initiated in 1991. The breeding population increased from 14 to 27 nests after this marking program began. Burrow types and ways to differentiate burrows used by owls from those used by California ground squirrels (Spermophilus beecheyi) are outlined. The importance of burrows and their management is discussed with reference to the natural history of the owl.