Western Burrowing Owl (Athene Cunicularia Hypugaea) As an Endangered Or Threatened Species Under the California Endangered Species Act
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PETITION TO THE STATE OF CALIFORNIA FISH AND GAME COMMISSION AND SUPPORTING INFORMATION FOR LISTING THE CALIFORNIA POPULATION OF THE WESTERN BURROWING OWL (ATHENE CUNICULARIA HYPUGAEA) AS AN ENDANGERED OR THREATENED SPECIES UNDER THE CALIFORNIA ENDANGERED SPECIES ACT PETITIONERS Center for Biological Diversity Santa Clara Valley Audubon Society Contact: Jeff Miller Contact: Craig Breon (510) 625-0136, [email protected] (408) 252-3748, [email protected] 370 Grand Avenue, Suite 5 22221 McClellan Road Oakland, CA 94610 Cupertino, CA 95014 Defenders of Wildlife San Bernardino Valley Audubon Society Contact: Kim Delfino Contact: Tony Metcalf (916) 313-5809, [email protected] (909) 242-7038, [email protected] 926 J Street, Suite 522 P.O. Box 10973 Sacramento, CA 95814 San Bernardino, CA 92423-0973 California State Park Rangers Association Tri-County Conservation League Contact: Geary Hund Contact: Jack Bath (909) 940-5617, [email protected] (909) 627-9071, [email protected] 17801 Lake Perris Drive P. O. Box 51127 Perris, CA 92571 Riverside, CA 92517 Petitioners Center for Biological Diversity, Santa Clara Valley Audubon Society, Defenders of Wildlife, San Bernardino Valley Audubon Society, California State Park Rangers Association, and Tri-County Conservation League petition the California Fish and Game Commission to list the western burrowing owl as a state endangered or threatened species. Petitioners submit this petition pursuant to the California Endangered Species Act, Fish and Game Code §§ 2070 et seq., on their own behalf and on behalf of their members and staff with an interest in protecting the western burrowing owl and its habitat in California. Lead petitioner Center for Biological Diversity is a nonprofit environmental organization dedicated to the protection of native species and their habitats. The Center works to protect and restore natural ecosystems and imperiled species through science, education, policy, and environmental law. The Santa Clara Valley Audubon Society works to maintain, preserve, and protect native animal and plant habitats and to foster a greater public awareness of our environment, with emphasis on birds and their ecosystems, particularly in Santa Clara County and the San Francisco Bay Area. Defenders of Wildlife is a nonprofit organization dedicated to the protection of all native wild animals and plants in their natural communities. Defenders programs encourage protection of entire ecosystems and interconnected habitats while protecting predators that serve as indicator species for ecosystem health. The San Bernardino Valley Audubon Society is a non-profit corporation dedicated to conserving and restoring natural ecosystems, focusing on birds and other wildlife for the benefit of humanity and the earth’s biological diversity. The California State Park Rangers Association is an organization of park professionals dedicated to advancement of the highest principles of public service, established to support and preserve California State Parks for present and future generations. The Tri-County Conservation League, Inc. is a public interest corporation with a membership that promotes the educational, recreational and conservation values of the natural resources of the Santa Ana River and its drainage system in Riverside, San Bernardino, and Orange Counties. 2 TABLE OF CONTENTS I. EXECUTIVE SUMMARY. .. .. .. 5 II. STATUTORY FRAMEWORK AND REQUESTED ACTION. .. .. .7 III. ECOLOGY OF THE WESTERN BURROWING OWL. .. .. .9 A. DESCRIPTION. .. .. .. .9 B. TAXONOMY. .. .. .. .. .9 C. REPRODUCTION AND GROWTH. .. .. .9 D. MOVEMENT. .. .. .. .. .11 E. FEEDING. .. .. .. .. .. .12 F. PREDATION. .. .. .. .. .. 13 IV. HABITAT REQUIREMENTS. .. .. .. .14 V. RANGE. .. .. .. .. .. .. .. .. 16 VI. HISTORICAL AND RECENT DISTRIBUTION AND ABUNDANCE. .. .. 17 A. NORTHERN COASTAL CALIFORNIA. .. .. 18 B. NORTHERN DESERT RANGE. .. .. .. 18 C. CENTRAL VALLEY. .. .. .. .. 19 1. NORTHERN CENTRAL VALLEY. .. .. 19 2. MIDDLE CENTRAL VALLEY. .. .. .21 3. SOUTHERN CENTRAL VALLEY. .. .. .27 D. SAN FRANCISCO BAY AREA. .. .. 30 E. CENTRAL WESTERN CALIFORNIA. .. .. .37 F. SOUTHWESTERN CALIFORNIA. .. .. .39 G. IMPERIAL VALLEY. .. .. .. .. 48 H. COACHELLA VALLEY. .. .. .. .. 49 I. SOUTHERN DESERT RANGE. .. .. .. .. .49 VII. POPULATION TRENDS. .. .. .. .53 VIII. NATURE, DEGREE, AND IMMEDIACY OF THREAT. .. .. .. .56 A. URBAN DEVELOPMENT. .. .. .. .. .56 B. THREATS TO IMPERIAL VALLEY AND SOUTHERN CENTRAL VALLEY OWL POPULATIONS. .. .. .. .. .59 C. DESTRUCTION OF BURROWING RODENTS. .. .. .. 60 D. RELOCATION OF OWLS. .. .. .. .. .61 E. AGRICULTURAL PRACTICES. .. .. .. .. 63 F. PESTICIDES. .. .. .. .. .. .65 G. PREDATION. .. .. .. .. .. 67 H. DISEASE. .. .. .. .. .. .. 68 I. SMALL POPULATION SIZES. .. .. .. .. .. 68 J. OTHER ANTHROPOGENIC FACTORS. .. .. .. .69 3 IX. INADEQUACY OF EXISTING MANAGEMENT EFFORTS. .. .. .. 72 A. FEDERAL REGULATORY MECHANISMS. .. .. .. .72 B. STATE REGULATORY MECHANISMS. .. .. .. 76 C. REGIONAL AND LOCAL GOVERNMENT PLANS. .. .. .. .81 X. RECOMMENDED MANAGEMENT AND RECOVERY ACTIONS. .. .. .. .84 A. LIST THE BURROWING OWL AS A STATE ENDANGERED OR THREATENED SPECIES. .. .. .. .. .. .. .. 84 B. PROTECT REMAINING BREEDING GROUPS AND PAIRS AND PROTECT AND ENHANCE BREEDING HABITAT. .. .. .. .. .. .. 84 C. AMENDMENTS TO EXISTING MANAGEMENT AND LAND USE PLANS. .. 85 D. AGENCIES AND ORGANIZATIONS THAT SHOULD BE INVOLVED. .. .. .85 E. BURROWING OWL MANAGEMENT IMPACTS ON OTHER SPECIES. .. .. 85 F. MONITORING PROGRAMS AND STUDIES. .. .. .. .. .86 XI. SIGNATURE PAGE. .. .. .. .. .. .. .. .87 XII. INFORMATION SOURCES. .. .. .. .. .. .. .. 88 A. INDIVIDUALS SUPPORTING PETITIONED ACTION. .. .. .. 88 B. BIBLIOGRAPHY OF LITERATURE CITED. .. .. .. .. 89 C. PERSONAL COMMUNICATION SOURCES. .. .. .. .. .114 XIII. APPENDICES. .. .. .. .. .. .. .. .. ... 115 A. APPENDIX 1 – CALIFORNIA BURROWING OWL RANGE AND DISTRIBUTION MAP. .. .. .. .. .. .. .. .. .. .. .. ... 115 B. APPENDIX 2 – TABLE OF ESTIMATED DENSITY, BREEDING PAIRS, AND POPULATION TREND, BY REGION. .. .. .. .. .. .. 116 C. APPENDIX 3 – DESANTE ET AL. 1996, “THE DISTRIBUTION AND RELATIVE ABUNDANCE OF BURROWING OWLS IN CALIFORNIA: EVIDENCE FOR A DECLINING POPULATION” . .. .. .. .118 4 I. EXECUTIVE SUMMARY Petitioners Center for Biological Diversity, Santa Clara Valley Audubon Society, Defenders of Wildlife, San Bernardino Valley Audubon Society, California State Park Rangers Association, and Tri-County Conservation League submit this petition to list the California population of the western burrowing owl (Athene cunicularia hypugaea) as an endangered or threatened species under the California Endangered Species Act, Fish and Game Code §§ 2070 et seq. (“CESA”). This petition demonstrates that the western burrowing owl is in serious danger of becoming extinct throughout a significant portion of its range in California and clearly warrants listing under CESA, based on the factors discussed herein. The western burrowing owl is a small ground-nesting bird of prairie and grassland habitats, which in many areas has adapted to human-altered habitats as urban development and agriculture have eliminated natural grasslands. Burrowing owls in the western United States rely upon burrows dug by burrowing mammals for nests, primarily those of ground squirrels in California. Burrowing owls also require open fields with adequate food supply for foraging habitat, low vegetative cover to allow owls to watch for predators, and adequate roosting sites. These owls can often be seen perched or standing by their burrow or hunting insects, rodents, amphibians, or small birds in open fields. Nesting season is from February through August, with most pairs usually fledging 4 or 5 young. After the nesting season, most owls in California remain throughout the winter as year-round residents and owls from others areas augment resident California populations. Burrowing owls are susceptible to predators that can access their nest chamber, such as foxes, coyotes, skunks, raccoons, and snakes, and are also preyed upon by various other raptor species, such as hawks, eagles, and other species of owls. Burrowing owls in California historically ranged throughout the Central Valley, were found in suitable habitat in coastal areas from Marin County south to the Mexican border, and sparsely inhabited desert areas in the northeastern and southeastern portions of the state. Densities of owls in some areas of the state.