"Davis citizens, burrowing owls need your help! Please contact the Davis City Council and ask them to adopt Protection and Conservation Measures. We recommend these Measures. Some Measures are inexpensive and can be implemented immediately, such as, mowing the vegetation at the Wildhorse Ag Buffer."
Burrowing Owl Preservation Society
A non-profit organization dedicated to increasing the burrowing owl population
through education and enhancement of grassland habitat
14841 CR 91 B, Woodland CA 95695
Burrowing Owl Protection and Conservation Measures
Require project proponents hire “qualified and experienced” burrowing owl biologists, as
defined in the 2012 CDFW Staff Report on Burrowing Owl Mitigation (Staff Report).
Biologists must have adequate survey experience with this species, understand their local
ecology and habitat requirements, and be familiar with applicable state and federal
statutes. This ensures that, if and when individual owls are detected, the conservation
needs of burrowing owls are considered. This also affords the project proponent
assurance that they do not violate the law.
Nest burrow protection and associated habitat enhancement Where nest burrows occur on
City property, enhance the surrounding habitat through vegetation management. Threats,
such as ground disturbing activities, harassment, predation by domestic animals, and
rodenticide use must also be minimized. Consider all open land, empty lots, and fields
within the City as burrowing owl foraging habitat and require that project proponents
mitigate habitat loss
Require project proponents to ensure that alternative burrows are available before
“Burrow Exclusion and Closure” is implemented. Burrow exclusion allows developers to
hire biologists to install one-way doors in burrow openings throughout a project site to
permanently exclude burrowing owls from their shelter. After an owl exits a burrow, the
burrow is permanently destroyed to enable ground-disturbing construction activities to
move forward. Burrowing owls use burrows for nesting, roosting, protection from
inclement weather, and to evade predators. Without alternative burrows, owls will likely
die because they do not have a safe place to retreat. The Environmental Impact Report
(EIR) must include a Burrowing Owl Artificial Burrow and Exclusion Plan as described
in Appendix E of the Staff Report before City Council certifies the Final EIR.
Commitment to specific mitigation measures
Require that project proponents specifically state how they will implement mitigation
measures recommended in the CDFW Staff Report. The language used in the Staff
Report leaves much room for interpretation, and states recommendations rather than
requirements. It falls to the lead agency to ensure project proponents comply with the
Staff Report recommendations.
For example, the Staff Report recommends that project impact evaluations include
breeding season surveys that are to be conducted at least three weeks apart during the
peak of the breeding season (in California 15 April to 15 July). Commenters for the Mace
Ranch Innovation Center DEIR noted that Sycamore Environmental conducted
burrowing owl surveys in October and December, rather than during breeding season
when owls are more likely to be active. The response from the project proponent was that
the breeding season surveys are recommended but not required.
Require that project proponents specifically state the ratio at which they will replace the
permanent loss of burrowing owl habitat, not simply that they will comply with the Staff
Report. The 2012 Staff Report does not specify a minimum habitat replacement
recommendation. The 1995 Staff Report recommended 6.5 acres per pair or individual
owl. Loss of burrowing owl habitat in the City of Davis shall be mitigated with 10 acres
of habitat better than that of the impact area. Mitigation habitat shall be obtained within
Require the vegetation on the agriculture buffers be restored to replicate California native
prairie. Currently, project proponents plant trees and shrubs, which results in unsuitable
habitat conditions for burrowing owls because these features limit foraging opportunities
and also provide habitat for their predators.
Artificial burrow installation
Burrowing owls rely on burrows created by California ground squirrels (Spermophilus
beechyi). Where natural burrows are absent or unavailable, artificial burrows will be
installed on City owned property where there is otherwise suitable habitat. To ensure
occupancy, it is imperative that these artificial burrows are maintained and a management
plan must be implemented.
Yolo Habitat Conservancy mitigation fees
Obtain an MOU with CDFW to collect burrowing owl mitigation fees now to be held to
purchase burrowing owl conservation easements through the Yolo Habitat Conservancy,
when it is permitted.
Once a year the City, in collaboration with local wildlife advocacy groups, will evaluate
the effectiveness of these Protection and Conservation Measures and propose revisions, if
necessary. The City will monitor the population and the numbers of acres of mitigation
habitat acquired and managed.
DeSante, D. F., E. D Ruhlen, and R. Scalf. 2007. The distribution and relative abundance
of burrowing owls in California during 1991–1993: Evidence for a declining population
and thoughts on its conservation. Pages 1-41 in J. H. Barclay, K. W. Hunting, J. L.
Lincer, J. Linthicum, and T. A. Roberts, editors. Proceedings of the California
Burrowing Owl Symposium, 11-12 November 2003 Sacramento, California, USA. Bird
Populations Monographs No. 1. The Institute for Bird Populations and Albion
Environmental, Inc., Point Reyes Station, CA.
Foley, J, S. Menzel, C. Portman, R.L. Wilkerson. A Precipitous Decline of Western
Burrowing Owls in Yolo County, California, as Detected by Citizen Scientists.
Johnson, B.S. 1997 Demography and Population Dynamics of the Burrowing Owl.
Journal of Raptor Research Report 9:28-33
Rose, J. 2005 Burrowing Owl: Notes, Sketches, Photographs and Diagrams. Held by
Burrowing Owl Preservation Society. Copy provided to Yolo County Archives
Widdicombe, J.H. 2007 Nesting Burrowing Owls in Solano and Yolo Counties,
California, 2000-2005 Page 56 in J.H. Barclay, K. W. Hunting, J. L. Lincer, J. Linthicum,
and T. A. Roberts, editors. Proceedings of the California Burrowing Owl Symposium, 11-
12 November 2003 Sacramento, California, USA. Bird Populations Monographs
No. 1. The Institute for Bird Populations and Albion Environmental, Inc., Point Reyes
Wilkerson, R.R., and R.B. Siegel 2010 Assessing changes in distribution and abundance
of burrowing owls in California, 1993-2007 Bird Populations 10:1-36
Jim Rose, John McNerney, and Brenda Johnson personal communications and emails.
Held by Burrowing Owl Preservation Society. Copy provided to Yolo County Archives
Burrowing Owl Preservation Society Page 3