Burrowing Owl Habitat Enhancement

The Western Burrowing Owl has been listed by the State of California as a Species of Special Concern. In California these owls are primarily threatened by habitat loss due to urban development, eradication of grand squirrels (which provide the burrows that owls use to nest), and intensive agricultural practices. In 2015, we started partnering with other organizations to monitor and enhance habitat for two of the last Burrowing Owl populations in the San Francisco Bay Area. ​One project is at the Warms Springs Unit of the Don Edwards San Francisco Bay National Wildlife Refuge in Fremont. The other is at the San Jose-Santa Clara Regional Wastewater Facility near Alviso.

​At both sites we carry out a variety of vegetation management tasks to maintain suitable habitat for the owls. We construct and maintain artificial burrow systems, enhance potential foraging areas with native plants and structural features, and coordinate with the Santa Clara Valley Audubon Society to protect other special status species at these locations. In addition, at the Alviso site we are experimenting with using high-salinity water to suppress weeds on the mounds used by owls. Volunteers are crucial for the success of these projects. ​