Accordion side navigation Bighorn Sheep Desert Bighorn Sheep Overview Natural History Monitoring Efforts How to see a Desert Bighorn How You Can Help Scientific Literature & Works Cited Contact Program Peninsular Desert Bighorn Sheep Overview Range and Habitat Bighorn Behavior Recovery and Conservation Photos Selected Program Literature Program Staff Sierra Nevada Bighorn Sheep Overview Natural History Disease Risk Recovery Program Yosemite Bighorn Sequoia Kings Bighorn Migrating Mural See also: Bighorn Sheep Hunting Sierra Nevada Bighorn Sheep Recovery Program Literature Documents by Category Key: P - Peer Reviewed Publication, D - Dissertation, T - Thesis, R - Other Reports Sierra Nevada Bighorn Sheep Recovery Program Quarterly and Semi-Annual Reports (2007 - 2009) July-December 2009 (PDF) April-June 2009 (PDF) January-March 2009 (PDF) October-December 2008 (PDF) July-September 2008 (PDF) April-June 2008 (PDF) January-March 2008 (PDF) April-June 2007 (PDF) July-September 2007 (PDF) October-December 2007 (PDF) Sierra Nevada Bighorn Sheep Annual Population Monitoring Reports (1979 - present) May 2021-April 2022 (PDF) May 2020-April 2021 (PDF) May 2019-April 2020 (PDF) 2022 Status of Bighorn Sheep Herds in Yosemite National Park (PDF) May 2018-April 2019 (PDF) May 2017-April 2018 (PDF) 2018 Status of Sierra Nevada Bighorn Sheep Herds in Yosemite National Park (PDF) May 2016-April 2017 (PDF) May 2016-April 2017 Supplemental Materials (PDF) May 2015-April 2016 (PDF) May 2014-April 2015 (PDF) May 2013-April 2014 (PDF) May 2012-April 2013 (PDF) May 2011-April 2012 (PDF) May 2010-April 2011 (PDF) May 2009-April 2010 (PDF) May 2008-April 2009 (PDF) May 2007-April 2008 (PDF) May 2006-April 2007 (PDF) May 2005-April 2006 (PDF) May 2004-April 2005 (PDF) Jan 2003-December 2003 (PDF) Jan 2002-December 2002 (PDF) Jan 2001-December 2001 (PDF) Jan 2000-December 2000 (PDF) Jan 1999-December 1999 (PDF) 1998 Survey Results (PDF) 1995-97 Status (PDF) 1995 Status (PDF) 1994 Mount Baxter herd census (PDF) 1993 Lee Vining Status (PDF) Population dynamics and movement patterns of bighorn sheep reintroduced in the Sierra Nevada, California (PDF) 1991 Wheeler Ridge Survey (PDF) Results of the 1990 census of the Mt. Langley bighorn sheep (PDF) 1989 Status of bighorn sheep in California (PDF) Historical Demographics (PDF) 1987 Status Mount Baxter (PDF) Mountain sheep in California: A historical perspective (PDF) 1986 Wheeler Ridge and Mt. Langley Survey Results (PDF) 1982 Mount Baxter herd census (PDF) Sierra Nevada bighorn sheep: History and population ecology (PDF) The Relocation of Bighorn Sheep in the Sierra Nevada of California (PDF) The Mount Baxter herd: Past and future census (PDF) Sierra Nevada bighorn sheep: An analaysis of management alternatives (PDF) Demography and Management P - Wagler, B. L., R. A. Smiley, A. B. Courtemanch, G. Anderson, D. Lutz, D. McWhirter, D. Brimeyer, P. Hnilicka, C. P. Massing, D. W. German, T. R. Stephenson, K. L. Monteith. 2022. Effects of helicopter net-gunning on survival of bighorn sheep. Journal of Wildlife Management 2022:1-18. P - Bleich, V. C., J. D. Wehausen, S. G. Torres, K. Anderson, and T. R. Stephenson. 2021. Fifty years of bighorn sheep translocations: details from California (1971-2020) (PDF). 2021 Desert Bighorn Council Transactions 56:1-32. P - Flesch, E. P., T. A. Graves, J. M. Thomson, K. M. Proffitt, P. J. White, T. R. Stephenson, R. A. Garrott. 2020. Evaluating wildlife translocations using genomics: A bighorn sheep case study (PDF). Ecology and Evolution 2020: 13687-13704. P - Conner, M. M., T. R. Stephenson, D. W. German, K. L. Monteith, A. P. Few., E. H. Blair. 2018. Survival analysis: Informing recovery of Sierra Nevada bighorn sheep. Journal of Wildlife Management 82:1442-1458. R - Few, A.P., Knox, K.,German, D. W., Wehausen, J. D., and Stephenson, T. R. 2015 Translocation Plan for Sierra Nevada Bighorn Sheep: A Focus on Strategic Planning (PDF). California Department of Fish and Wildlife. March, 2015. R - Few, A.P., German, D. W., Hatfield, B. E., Knox, K., Spitz, D., Wehausen, J. D. , and Stephenson, T. R. 2014 Addendum to the Translocation Plan for SNBS (PDF). California Department of Fish and Wildlife. March, 2014. R - Wehausen, J. D., and Jones F. L. The historical distribution of bighorn sheep in the Sierra Nevada, California (PDF). California Fish and Game 100(3):417-435; 2014. R - Few, A.P., German, D. W., Wehausen, J. D. , Pierce, B. M., and Stephenson, T. R. Translocation Plan for Sierra Nevada Bighorn Sheep (PDF). California Department of Fish and Wildlife. February, 2013. P - Johnson, H. E., Mills, L. S., Wehausen, J. D. , Stephenson, T. R. and Luikart, G. Translating Effects of Inbreeding Depression on Component Vital Rates to Overall Population Growth in Endangered Bighorn Sheep (PDF). Conservation Biology, Volume 25, No. 6, 1240–1249. Blackwell Publishing, Ltd.; 2011. P - Johnson, H. E., Mills, L. S., Wehausen, J. D. and Stephenson, T. R. Combining ground count, telemetry, and markresight data to infer population dynamics in an endangered species (PDF). Journal of Applied Ecology 47:1083-1093. Wiley-Blackwell; 2010. P - Johnson, H. E., Mills, L. S., Stephenson, T. R and . Wehausen, J. D. Population-specific vital rate contributions influence management of an endangered ungulate (PDF). Ecological Applications pp. 1753-1765. Ecological Society of America.; 2010. P - Williams, R. D. Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Sierra Nevada Bighorn Sheep (Ovis canadensis sierrae) and Taxonomic Revision (PDF). US Federal Register. U.S. Fish and Wildlife Service; 2008. P - Thompson, S. Recovery plan for the Sierra Nevada bighorn sheep (PDF). United States Fish and Wildlife Services; 2007. R - Ernest H. B. Captive breeding Contingency plan: A Guide for Captive Breeding of Sierra Nevada Bighorn Sheep (PDF). Report for Interagency Agreement # P9980059 between California Department of Fish and Game and Wildlife Health Center, School of Veterinary Medicine, University of California, Davis CA. 12/15/2001. R - Wehausen, J.D.An Analysis of Translocation Options for the Recovery of Sierra Nevada Bighorn Sheep (PDF). California Department of Fish and Game; 6/1998. R - Sierra Nevada Interagency Advisory Group. A Conservation Strategy of Sierra Nevada Bighorn Sheep (PDF). California Department of Fish and Game; 5/1997. P - Bleich, V. C., Wehausen, J.D., K. R. Jones and R. A. Weaver. Status of bighorn sheep in California, 1989 and translocations from 1971 through 1989 (PDF). Desert Bighorn Council 1990 Transactions. Desert Bighorn Council; 1990. R - Wehausen, J. D. A history of bighorn sheep management in the Sierra Nevada (PDF). Preceedings of the State of the Sierra Symposium. State of the Sierra Symposium; 1988. R - Sierra Nevada Interagency Advisory Group. Sierra Nevada Bighorn Sheep Recovery and Conservation Plan (PDF). California Department of Fish and Game; 9/1984. Habitat Use and Modelling P - Rankins, S. T., T. R. Stephenson, and K. L. Monteith. 2024. Sociality modulates nutritional carrying capacity of an endangered species. Frontiers in Ecology and Evolution 10.3389/fevo.2024.1417970. P - John, C., T. Avgar, K. Rittger, J. A. Smith, L. W. Stephenson, T. R. Stephenson, and E. Post. 2024. Pursuit and escape drive fine-scale movement variation during migration in a temperate alpine ungulate. Scientific Reports Nature Portfolio 14:1-11. P - Denryter, K., T. R. Stephenson, and K. L. Monteith. 2024. Migratory behaviours are risk-sensitive to physiological state in an elevational migrant. Conservation Physiology 12:1-12. P - Denryter, K., T. R. Stephenson, K. L. Monteith. 2021. Broadening the migratory portfolio of altitudinal migrants (PDF). Ecology 102:1-4. P - Anderson, K., M. L. Cahn, T. R. Stephenson, A. P. Few, B. E. Hatfield, D. W. German, J. Weissman, B. Croft. Cost distance models to predict contact between bighorn sheep and domestic sheep. 2022. Wildlife Society Bulletin 1329:1-22. P - Denryter, K., M. M. Conner, T. R. Stephenson, D. W. German, K. L. Monteith. 2022. Survival of the fattest: How body fat and migration influence survival in highly seasonal environments (PDF). Functional Ecology DOI: 10.1111/1365-2435.14151. P - Berger, D. J., D. W. German, C. John, R. Hart, T. R. Stephenson. 2022. Seeing is be-leaving: Perception informs migratory decisions in Sierra Nevada bighorn sheep (Ovis canadensis sierrae) (PDF). Frontiers in Ecology and Evolution 10:1-20. P - Denryter, K. D. W. German, Stephenson, T. R., K. L. Monteith. 2020. State- and context-dependent applications of an energetics model in free-ranging bighorn sheep. Ecological Modelling 440:109349. P - Stephenson, T. R. , D. W. German, E. F. Cassirer, D. P. Walsh, M. E. Blum, M. Cox, K. M. Stewart, K. L. Monteith. 2020. Linking population performance to nutritional condition in an alpine ungulate. Journal of Mammalogy 101:1244-1256. P - Spitz, D. B., M. Hebblewhite, and T. R. Stephenson. 2017. ‘MigrateR’: extending model-driven methods for classifying and quantifying animal movement behavior (PDF). Ecography 40:788-799. P - Spitz, D., M. Hebblewhite, T. R. Stephenson and D. W. German. 2018. How plastic is migratory behavior? Quantifying elevational movement in a partially migratory alpine ungulate, the Sierra Nevada bighorn sheep (Ovis canadensis sierrae) (PDF). Canadian Journal of Zoology 96:1385-1394. T - Spitz, D.B. Does Migration Matter? Causes and Consequences of Migratory Behavior in Sierra Nevada Bighorn Sheep (PDF). Doctoral Thesis, University of Montana. University of Montana; 2015. R - Klinger, R. C., Few, A.P., Knox, K. Hatfield, B. E., Clark, J,, German, D. W., and Stephenson, T. R. Evaluating Potential Overlap Between Pack Stock and Sierra Nevada Bighorn Sheep (Ovis canadensis sierrae) in Sequoia and Kings Canyon National Parks, California (PDF). United States Geology Survey Report 2015-1101, 2015. P - Greene, L., Hebblewhite, M., and Stephenson, T.R. Short-term vegetation response to wildfire in the eastern Sierra Nevada: Implications for recovering an endangered ungulate (PDF). Journal for Arid Environment, Vol. 87, pp. 118-128. Elsevier; 2012. P - Schroeder, C. A., Bowyer, R.T., Bleich, V.C. and Stephenson, T.R. Sexual segregation in Sierra Nevada bighorn sheep, Ovis canadensis sierrae: Ramifications for conservation (PDF). Arctic, Antarctic, and Alpine Research, Vol. 42, No. 4, pp. 476-489. Regents of the University of Colorado; 2010. T - Greene, L. Short-term effects of wildfire on Sierra Nevada bighorn sheep habitat ecology (PDF). Thesis, University of Montana. University of Montana; 2010. T - Latham, E. L. S. Changes in bighorn sheep habitat of the Sierra Nevada (PDF). Thesis, University of Calgary. University of Calgary; 9/1/2010. T - Schoeder, C. Sexual segregation and foraging ecology of sierra nevada bighorn sheep during winter (PDF). Thesis, Idaho State University. Idaho State University; 6/1/2007. R - Johnson, H. E., Bleich, V. C.. and Stephenson, T. R. Habitat selection by mountain sheep and mule deer: A step toward understanding ecosystem health from the desert to the alpine (PDF). Department of fish and game resource assessment program: Final report. University of California Davis Wildlife Health Center; 5/15/2005. R - Wehausen, J. D. The role of precipitation and temperature in the winter range diet quality of mountain sheep of the Mount Baxter herd, Sierra Nevada (PDF). Biennial Symposium of North American Wild Sheep and Goat Council 8:279:292. North American Wild Sheep and Goat Council; 1992. P - Wehausen, J. D., Bleich, V. C. and Weaver, R.A. Mountain sheep in California: A historical perspective (PDF). Transactions Western Section The Wildlife Society 23:65:74. The Wildlife Society; 1987. Predation P - Gammons, D., J. L. Davis, D. W. German, K. Denryter, J. D. Wehausen and T. R. Stephenson. Predation impedes recovery of Sierra Nevada bighorn sheep (PDF). California Fish and Wildlife Special CESA. California Department of Fish and Wildlife; 2021. T - Forshee, S. C. Life on the Edge: Risk of Predation Drives Selection of Habitat and Survival of Neonates in Endangered Sierra Nevada Bighorn Sheep (PDF). University of Montana; 2018. P - Johnson, H. E., Hebblewhite, M.H. , Stephenson, T.R. , German, D.W. Pierce, B.M. and Bleich,V. B. Evaluating apparent competition in limiting the recovery of an endangered ungulate (PDF). Oecologia. 171(1):295-307. doi: 10.1007/s00442-012-2397-6. Jan. 2013. P - Villepique, J.T., B. M. Pierce,V. C. Bleich,and R. T. Bowyer. Diet of cougars (Puma conolor) following a decline in a population of mule deer (Odocoileus hemionus): lack of evidence for switching prey (PDF). Southwestern Naturalist 56(2):187-192. 2011. R - Bleich, V. C. and B. M. Pierce. Cougar management guidelines. Records of North American Big Game, 12th Edition (PDF). Conservation Connection; 2007. R - Pierce, B. M. and Bleich, V.C. Mountain lion. Wild Mammals of North America (PDF). The Johns Hopkins University Press; 10/21/2003. R - Stevens, E. H. Predator damage management to protect the federally endangered bighorn sheep, California (PDF). USWS. U.S. Fish and Wildlife Service; 12/1/1999. P - Wehausen, J. D. Effects of mountain lion predation on bighorn sheep in the Sierra Nevada and Granite Mountains of California (PDF). Wildlife Society Bulletin, Vol. 24, No. 3: pp. 471-279. The Wildlife Society; 1996. Species Designation P - Massing, C. P., D. W. German, and T. R. Stephenson. 2024. Morphologic differences in bighorn populations of California. The Southwestern Naturalist 67:263-273. P - Wehausen, J. D., Bleich, V. C. and Ramey, R.R. II. Correct nomenclature for Sierra Nevada bighorn sheep (PDF). California Fish and Game 91(1) 000:000. California Department of Fish and Game; 2005. P - Wehausen, J. D. and Ramey, R.R. II. Cranial morphometric and evolutionary relationships in the northern range of Ovis canadensis (PDF). Journal of Mammology, 81(1):145-151, 2000. American Society of Mammologists; 2000. Endangered Species Listing and Environmental Assessment R - Report to the Fish and Game Commission Five-Year Species Review of Sierra Nevada Bighorn Sheep (Ovis canadensis sierrae) (PDF) (CDFW, March 2021) R - Notice of Determination(NOD): US Forest Service Environmental Assessment for Capturing Sierra Nevada Bighorn Sheep Within Portions of the Ansel Adams, Hoover, John Muir, Golden Trout, and South Sierra Wilderness Areas (PDF) (CDFW, Sept 2012) R - Notice of Intent (NOI): Inyo National Forest Environmental Assessment - Capturing Sierra Nevada Bighorn Sheep Within Portions of the Ansel Adams, Hoover, John Muir, Golden Trout, and South Sierra Wilderness Areas (PDF) (CDFW, Sept 2012) R - Findings of No Significant Impact (FONSI): Capturing Sierra Nevada Bighorn Sheep Within Portions of the Ansel Adams, Hoover, John Muir, Golden Trout, and South Sierra Wilderness Areas (PDF) (USFS, June 2012) R - Environmental Assessment (EA): Capturing Sierra Nevada Bighorn Sheep Within Portions of the Ansel Adams, Hoover, John Muir, Golden Trout, and South Sierra Wilderness Areas (PDF) (USFS, May 2012) R - Environmental Assessment (EA) - Appendix A: Capturing Sierra Nevada Bighorn Sheep Within Portions of the Ansel Adams, Hoover, John Muir, Golden Trout, and South Sierra Wilderness Areas (PDF) (USFS, May 2012) R - Environmental Assessment (EA) - Appendix B: Capturing Sierra Nevada Bighorn Sheep Within Portions of the Ansel Adams, Hoover, John Muir, Golden Trout, and South Sierra Wilderness Areas (PDF) (USFS, May 2012) R - Environmental Assessment (EA) - Appendix C: Capturing Sierra Nevada Bighorn Sheep Within Portions of the Ansel Adams, Hoover, John Muir, Golden Trout, and South Sierra Wilderness Areas (PDF) (USFS, May 2012) R - Environmental Assessment (EA) - Appendix D: Capturing Sierra Nevada Bighorn Sheep Within Portions of the Ansel Adams, Hoover, John Muir, Golden Trout, and South Sierra Wilderness Areas (PDF) (USFS, May 2012) R - Notice of Determination: Sequoia Kings Canyon National Parks EA (PDF) (CDFW, Oct 2011) R - Notice of Intent: Sequoia and Kings Canyon National Park EA (PDF) (CDFW, Oct 2011) R - Sierra Nevada Bighorn Sheep Environmental Assessment: Research and Recovery Actions (PDF) (Sequoia and Kings Canyon National Parks, June 2011) R - Sequoia and Kings Canyon National Parks Wilderness Minimum Tool Analysis (PDF) (Sequoia and Kings Canyon National Parks, June 2011) R - Sequoia and Kings Canyon National Parks Finding of No Significant Impact (PDF) (Sequoia and Kings Canyon National Parks, August 2011) R - 5-Year Review: Summary and Evaluation (PDF) (USFWS, 09/30/2008) R - Designation of Critical Habitat for the Sierra Nevada Bighorn Sheep (Ovis canadensis sierrae) and Taxonomic Revision; Final Rule (PDF). (Federal Register: 73 FR 45534 45604, 08/05/2008) R - Final Recovery Plan for the Sierra Nevada Bighorn Sheep (Ovis canadensis californiana) (PDF) (USFWS, 02/13/2008) R - Recovery Plan for the Sierra Nevada Bighorn Sheep (Ovis canadensis californiana) (PDF). (Federal Register: 73 FR 8345 8346, 02/13/2008) R - ETWP; Final Rule To List the Sierra Nevada Distinct Population Segment of the California Bighorn Sheep as Endangered (PDF). (Federal Register: 65 FR 20 30, 01/03/2000) R - Environmental Assessment (EA) For the Management of Mountain Lions to Protect Sierra Nevada Bighorn Sheep: Finding of No Signinificant Impact (PDF). (USFWS, 01/03/2000) R - ETWP; Emergency Rule To List the Sierra Nevada Distinct Population Segment of California Bighorn Sheep as Endangered (PDF). (Federal Register: 64 FR 19300 19309, 04/20/1999) Outdoor California R - Outdoor California - CDFW, 2006 (PDF) R - Outdoor California - CDFW, 2004 (PDF)