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Mexican Spotted Owl

Mexican Spotted Owl
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Ecology of the Mexican Spotted Owl

RMRS scientists have been at the forefront of efforts to understand the ecology of the threatened Mexican spotted owls for more than 25 years. Most of the existing scientific knowledge on the ecology of this owl was developed by RMRS scientists and their partners, and these scientists also have been actively engaged in transferring this knowledge to managers and in management and recovery planning for this owl. RMRS scientists today continue to be actively involved in developing new knowledge on this owl, synthesizing existing information, and working with managers to integrate habitat requirements for the owl and its' important prey species with land management plans.

Projects

  • Occupancy, reproduction, and landscape use by Mexican spotted owls in the Rodeo-Chediski Fire Area, Arizona, and nearby unburned areas
  • Integrating habitat requirements of Mexican spotted owls with USFS Desired Future Conditions for mixed - conifer and pine - oak forests
  • Effects of fuel treatments on fire-risk and habitat suitability for the Mexican spotted owl Demography and habitat use of Mexican spotted owls in the Sacramento Mountains, New Mexico
  • Recovery planning for the Mexican spotted owl

Recovery Planning

RMRS scientists have been engaged in efforts to recover the Mexican spotted owl since before it was listed as a Threatened Species in 1993. RMRS scientists have conducted studies on the ecology, demography, and habitat requirements of this species since 1984. These scientists and their cooperators have produced most of the existing scientific information on this species. RMRS scientists also actively participated in recovery planning for this owl. William M. Block has served as the Recovery Team Leader since 1993 and Joseph L. Ganey has served as a Recovery team member over that same period. In addition, past employees James P. Ward, Jr. (Post-doctoral Research Associate) and Will Moir (Research Ecologist, retired) also served on the initial Recovery Team while employed by RMRS, and were key co-authors on the original Recovery Plan published in 1995.

Management recommendations from the Mexican Spotted Owl Recovery Plan were formally adopted by the Southwestern Region of the US Forest Service in 1996 through an amendment to the Land Management Plans for all eleven National Forests within the Region. These recommendations continue to guide management on National Forest lands in this Region today.

Block and Ganey continue to serve on the Recovery Team, which in 2012 produced a revision to the original Recovery Plan based on new scientific information developed since 1995. This revision was approved and signed by the Regional Director, US Fish and Wildlife Service, in September 2012, and its' release is imminent. The revised plan aims to continue offering important protections to the owl and its' habitat while improving flexibility for land managers.

People

Block, William M    Biologist & Program Manager    928-556-2161
Ganey, Joseph L    Research Wildlife Biologist    928-556-2156
Reynolds, Richard T    Research Wildlife Biologist    970-498-2585
Strohmeyer, Brenda E    Supervisory Biological Science Technician    928-556-2185

Selected Publications

Arsenault D. P., A. Hodgson, and P. B. Stacey. 1997. Dispersal movements of juvenile Mexican Spotted owls (Strix occidentalis lucida) in New Mexico. Pages 47–57 in J. R. Duncan, D. H. Johnson, and T. H. Nicholls, editors. Biology and conservation of owls of the northern hemisphere. USDA Forest Service General Technical Report NC-190.

Bagne, K.E. and Finch, D.M. 2008. Developing a tool to assess wildlife species vulnerability to climate change. In New Mexico Forestry and Climate Change Workshop. November 20, 2008. Albuquerque, N.M. Forest Guild.

Barrowclough, G. F., and R. J. Gutiérrez. 1990. Genetic variation and differentiation in the spotted owl (Strix occidentalis). Auk 107:737-744.

Barrowclough, G. F., R. J. Gutiérrez, and J. G. Groth. 1999. Phylogeography of spotted owl (Strix occidentalis) populations based on mitochondrial DNA sequences: Gene flow, genetic structure, and a novel biogeographic pattern. Evolution 53:919-931.

Barrowclough, G. F., J. G. Groth, L. A. Mertz, and R. J. Gutiérrez. 2006. Genetic structure of Mexican spotted owl populations in a fragmented landscape. Auk 123:1090-1102.

Block, W. M., F. Clemente, J. F. Cully, J. L. Dick, Jr., A. B. Franklin, J. L. Ganey, F. P. Howe, W. H. Moir, S. L. Spangle, S. E. Rinkevich, D. L. Urban, J. P. Ward, Jr., G. C. White, and R. Vahle. 1995. Recovery plan for the Mexican Spotted Owl. US Fish and Wildlife Service. Albuquerque, NM.

Block, W. M., J. L. Ganey, P. E. Scott, and R. M. King. 2005. Prey ecology of the Mexican spotted owl in ponderosa pine-Gambel oak forests of northern Arizona. Journal of Wildlife Management 69:618-629.

Block, W. M., R. E, Russell, and J. L. Ganey. 2011. Occupancy and habitat associations of four species of sciurids in northern Arizona ponderosa pine – Gambel oak forest. The Southwestern Naturalist 56:193-203.

Bond, M. L., R. J. Gutiérrez, A. B. Franklin, W. S. LaHaye, C. A. May, and M. E. Seamans. 2002. Short-term effects of wildfires on spotted owl survival, site fidelity, and mate fidelity. Wildlife Society Bulletin 30:1022-1028.

Bond, M. L., D. E. Lee, R. B. Siegel, and J. P. Ward, Jr. 2009. Habitat use and selection by California spotted owls in a postfire landscape. Journal of Wildlife Management 73:1116-1124.

Bowden, D. C., G. C. White, A. B. Franklin, and J. L. Ganey. 2003. Estimating population size with correlated sampling unit estimates. Journal of Wildlife Management 67:1-10.

Bowden, T. S. 2008. Mexican spotted owl reproduction, home range, and habitat associations in Grand Canyon National Park. M.S. thesis. Montana State University. Bozeman. 87pp.

Cirrett-Galan, J. M., and E. E. R. Diaz. 1993. Estatus y distribucion del buho manchado Mexican Strix occidentalis lucida en Sonora, Mexico. Reporte Tecnico Parcial: Centro Ecologico de Sonora. Hermosillo, Sonora, Mexico.

Converse, S. J., W. M. Block, and G. C. White. 2006a. Small mammal population and habitat responses to forest thinning and prescribed fire. Forest Ecology and Management 228:263-273.

Converse, S. J., G. C. White, K. L. Farris, and S. Zack. 2006b. Small mammals and forest fuel reduction: National-scale responses to fire and fire surrogates. Ecological Applications 16:1717-1729.

Converse, S. J., G. C. White, and W. M. Block. 2006c. Small mammal responses to thinning and wildfire in ponderosa pine-dominated forests of the southwestern United States. Journal of Wildlife Management 70:1711-1722.

Delaney, D. K., T. G. Grubb, and P. Beier. 1999a. Activity patterns of nesting Mexican spotted owls. Condor 101:42-49.

Delaney, D. K., T. G. Grubb, P. Beier, L. L. Pater, and M. H. Reiser. 1999b. Effects of helicopter noise on Mexican spotted owls. Journal of Wildlife Management 63:60-76.

Delaney, D. K., and T. G. Grubb. 2004. Sound recordings of road maintenance equipment on the Lincoln national forest, New Mexico. USDA Forest Service Research Paper RMRS-RP-49. Rocky Mountain Research Station. Fort Collins, Colorado, USA.

Duncan, R. B., and R. Sidner. 1990. Bats in spotted owl pellets in southern Arizona. Great Basin Naturalist 50:197-200.

Duncan, R. B., and J. D. Taiz. 1992. A preliminary understanding of Mexican spotted owl habitat and distribution in the Chiricahua Mountains and associated sub-Mogollon mountain ranges in southeastern Arizona. Pages 58-61 in: A. M. Barton and S. A. Sloane, editors. Proceedings of the Chiricahua Mountains Research Symposium. Southwest Parks and Monuments Association, Tucson, Arizona, USA.

Duncan, R. B., and S. M. Speich. 1995. Spotted owl banding in sub-Mogollon Arizona, dispersal and movement: Current knowledge. North American Bird Bander 20(3):151. (Abstract)

Duncan, R. B., and S. M. Speich. 2002. Inter-and intra-mountain movements of Mexican spotted owls in southeastern Arizona: Results of a multi-year banding study, 1991 – 2001. Abstract, Annual meeting, Western Bird Banding Association. Bisbee, Arizona, USA.

Ganey, J. L. 1988. Distribution and habitat ecology of Mexican spotted owls in Arizona. Thesis, Northern Arizona University, Flagstaff, Arizona, USA.

Ganey, J. L. 1990. Calling behavior of spotted owls in northern Arizona. Condor 92:485-490.

Ganey, J. L. 1991. Developing and testing a predictive model for Mexican spotted owl habitat. Ph.D. dissertation. Northern Arizona University. Flagstaff, Arizona, USA

Ganey, J. L. 1992. Food habits of Mexican spotted owls in Arizona. Wilson Bulletin 104:321-326.

Ganey, J. L. 1998. The spotted owl. Pages 170-174 in: R. L. Glinski, editor. The Raptors of Arizona. University of Arizona Press, Tucson, Arizona, USA.

Ganey, J. L. 2004. Thermal regimes of Mexican spotted owl nest stands. Southwestern Naturalist 49:478-486.

Ganey, J. L., and R. P. Balda. 1989a. Distribution and habitat use of Mexican spotted owls in Arizona. Condor 91:355-361.

Ganey, J. L, and Balda, R. P. 1989b. Home range characteristics of spotted owls in northern Arizona. Journal of Wildlife Management 53:1159-1165.

Ganey, J. L., and R. P. Balda. 1994. Habitat selection by Mexican spotted owls in northern Arizona. Auk 111:162-169.

Ganey, J. L., and J. A. Dick. 1995. Habitat relationships of Mexican spotted owls: Current knowledge. Chapter 4:1-42 in: USDI Fish and Wildlife Service, Recovery plan for the Mexican spotted owl (Strix occidentalis lucida), Vol. II - Technical supporting information. USDI Fish and Wildlife Service, Albuquerque, New Mexico, USA.

Ganey, J. L., and M. A. Benoit. 2002. Using Terrestrial Ecosystem Survey data to identify potential habitat for the Mexican spotted owls on National Forest System lands: A pilot study. USDA Forest Service General Technical Report RMRS-GTR-86.

Ganey, J. L., and W. M. Block. 2005a. Winter movements and range use of radio-marked Mexican spotted owls. USDA Forest Service Rocky Mountain Research Station, General Technical Report RMRS-GTR-148-WWW.

Ganey, J. L., and W. M. Block. 2005b. Dietary overlap between sympatric Mexican spotted and great horned owls in Arizona. USDA Forest Service Rocky Mountain Research Station, General Technical Report RMRS- RP-57-WWW.

Ganey, J. L, R. H. Cassidy, and W. M. Block. 2008. Estimating canopy cover in forest stands used by Mexican spotted owls. US Forest Service Research Paper RMRS-RP-72WWW. 8pp.

Ganey, J. L., M. E. Alderson, R. P. Balda, and D. R. Patton. 1990. Developing a large-scale model for Mexican spotted owl habitat. Pages 182-190 in: P. R. Krausman and N. S. Smith, editors. Managing wildlife in the southwest. Arizona Chapter, The Wildlife Society. Phoenix, Arizona, USA.

Ganey, J. L., R. B. Duncan, and W. M. Block. 1992. Use of oak and associated woodlands by Mexican spotted owls in Arizona. p.125-128 in: P. F. Ffolliott, G. J. Gottfried, D. a. Bennett, V. M. Hernandez, C., A. Ortega-Rubio, and R. H. Hamre, editors. Ecology and management of oak and associated woodlands. USDA Forest Service General technical Report RM-218.

Ganey, J. L., R. P. Balda, and R. M. King. 1993. Metabolic rate and evaporative water loss of Mexican spotted and great horned owls. Wilson Bulletin 105:645-656.

Ganey, J. L, W. M Block, J. S. Jenness, and R. A. Wilson. 1997. Comparative habitat use of sympatric Mexican spotted and great horned owls. Journal of Wildlife Research 2:115–123.

Ganey, J. L., W. M. Block, J. K. Dwyer, B. E. Strohmeyer, and J. S. Jenness. 1998. Dispersal movements and survival rates of juvenile Mexican spotted owls in northern Arizona. Wilson Bulletin 110:206-217.

Ganey, J. L., W. M. Block, J. S. Jenness, and R. A. Wilson. 1999. Mexican spotted owl home range and habitat use in pine-oak forest: Implications for forest management. Forest Science 45:127-135.

Ganey, J. L., W. M. Block, and R. M. King. 2000. Roost sites of radio-marked Mexican spotted owls in Arizona and New Mexico: Sources of variability and descriptive characteristics. Journal of Raptor Research 34:270-278.

Ganey, J. L., W. M. Block, and S. H. Ackers. 2003. Structural characteristics of forest stands within home ranges of Mexican spotted owls in Arizona and New Mexico. Western Journal of Applied Forestry 18:189-198.

Ganey, J. L., G. C. White, D. C. Bowden, and A. B. Franklin. 2004. Evaluating methods for monitoring populations of Mexican spotted owls: a case study. Pages 337-385 in: W. L. Thompson, editor. Sampling rare and elusive species: Concepts, designs, and techniques for estimating population parameters. Island Press, Washington, D.C., USA.

Ganey, J. L., W. M. Block, J. P. Ward, Jr., and B. E. Strohmeyer. 2005. Home range, habitat use, and vital rates of Mexican spotted owls in two different environments. Southwestern Naturalist 50:323-333.

Ganey, J. L., A. Telles, and M. A. Ramsey. 2008. Status and ecology of Mexican spotted owls in the Gila Region. In: Natural history of the Gila, a symposium. New Mexico Journal of Botany, Special Issue 1:34-48.

Ganey, J. L., J. P. Ward, Jr., and D. W. Willey. 2011. Status and ecology of Mexican spotted owls in the Upper Gila Mountains Recovery Unit, Arizona and New Mexico. US Forest Service General Technical Report RMRS-GTR-256WWW. Rocky Mountain Research Station. Ft. Collins, CO. 94 pp.

Ganey, J. L., D. L. Apprill, T. A. Rawlinson, S. C. Kyle, R. S. Jonnes, and J. P. Ward, Jr. Nesting habitat of Mexican spotted owls in the Sacramento Mountains, New Mexico. In review: Journal of Wildlife Management.

Grubb, T. G., J. L. Ganey, and S. R. Masek. 1997. Canopy closure around nest sites of Mexican spotted owls in northcentral Arizona. Journal of Wildlife Management 61:336-342.

Gutiérrez, R. J. 1989. Hematazoa from the spotted owl. Journal of Wildlife Diseases 24:614-618.

Gutiérrez, R. J., and S. Harrison. 1996. Applying metapopulation theory to spotted owl management: a history and critique. Pages 167-185 in: D. R. McCullough, editor. Metapopulations and wildlife conservation. Island Press, Washington, D.C., USA. 429pp.

Gutiérrez, R. J., M. E. Seamans, and M. Z. Peery. 1996. Intermountain movement by Mexican spotted owls (Strix occidentalis lucida). Great Basin Naturalist 56:87-89.

Hodgson, A. 1996. Dispersal and habitat use of Mexican spotted owls in New Mexico. Thesis, University of Nevada, Reno, Nevada, USA.

Hunter, J. E., R. J. Gutiérrez, A. B. Franklin, and D. Olson. 1994. Ectoparasites of the spotted owl. Journal of Raptor Research 28:232-235.

James, M. A. 2005. Integrating forest restoration treatments with Mexican spotted owl habitat needs. Working Papers in Southwestern Ponderosa Pine Forest Restoration 14. Ecological Restoration Institute, Northern Arizona University. Flagstaff, AZ. 9pp.

Jenness, J.S. 2000. The effects of fire on Mexican spotted owls in Arizona and New Mexico. Thesis, Northern Arizona University, Flagstaff, Arizona, USA. http://www.jennessent.com/Literature/Thesis/

Jenness, J. S., P. Beier, and J. L. Ganey. 2004. Associations between forest fire and Mexican spotted owls. Forest Science 50:765-772.

Johnson, C. L. 1997. Distribution, habitat, and ecology of the Mexican spotted owl in Colorado. Thesis, University of Northern Colorado, Greeley, Colorado, USA.

Johnson, C. L., and R. T. Reynolds. 2002. Responses of Mexican spotted owls to low-flying military jet aircraft. USDA Forest Service Research Note RMRS-RN-12.

Keitt, T. H., A. B. Franklin, and D. L. Urban. 1995. Landscape analysis and metapopulation structure. Chapter 3:1-16 in: W. M. Block, F. Clemente, J. F. Cully, J. L. Dick, Jr., A. B. Franklin, J. L. Ganey, F. P. Howe, W. H. Moir, S. L. Spangle, S. E. Rinkevich, D. L. Urban, R. Vahle, J. P. Ward, Jr., and G. C. White. In: USDI Fish and Wildlife Service, Recovery Plan for the Mexican spotted owl (Strix occidentalis lucida). Vol. II - Technical supporting information. Albuquerque, New Mexico, USA.

Keitt, T. H., D. L. Urban, and B. T. Milne. 1997. Detecting critical scales in fragmented landscapes. Conservation Ecology (online) 1(1):4. http://www.consecol.org/vol1/iss4/art4.

Kuntz, W. A. 1998. Vocal variation in the Mexican spotted owl (Strix occidentalis lucida). Thesis, University of Nevada, Reno, Nevada, USA.

Kuntz, W. A., and P. B. Stacey. 1997. Preliminary investigation of vocal variation in the Mexican spotted owl (Strix occidentalis lucida): Would vocal analysis of the four-note location call be a useful field tool for individual identification? Pages 562-568 in: J. R. Duncan, D. H. Johnson, and T. H. Nicholls, editors. Biology and conservation of owls of the northern hemisphere. USDA Forest Service General Technical Report NC-190.

Kyle, S. C., and W. M. Block. 2000. Effects of wildfire severity on small mammals in northern Arizona ponderosa pine forests. PP. 163-168 in: W. K. Moser and C. F. Moser, editors. Fire and forest ecology: Innovative silviculture and vegetation management. Tall Timbers Fire Ecology Conference Proceedings 21. Tall Timbers Research Station. Tallahassee, FL.

Lavier, R. A. 2006. Effects of weather and habitat on site occupancy of Mexican spotted owls in the Sacramento Mountains, New Mexico. Thesis, Colorado State University, Fort Collins, Colorado, USA.

May, C. A. and R. J. Gutiérrez. 2002. Habitat associations of Mexican spotted owl nest and roost sites in central Arizona. Wilson Bulletin 114:457-466.

May, C. A., M. L. Petersburg, and R. J. Gutiérrez. 2004. Mexican spotted owl nest- and roost-site habitat in northern Arizona. Journal of Wildlife Management 68:1054-1064.

Mellin, T. C., W. J. Krausmann, W. J., K. B. Clark, and C. F. Enquist. 2000. Assessing gross changes within vegetation types associated with Mexican spotted owl habitat in New Mexico and Arizona. Pages unnumbered in: J. D. Greer, editor. Eighth Biennial Forest Service Remote Sensing Applications Conference. Albuquerque, New Mexico, USA. 12pp.

Mullet, T. C. 2008. Evaluation of two GIS habitat models and initial characterization of nesting and breeding-season roosting microhabitat for Mexican spotted owls in the Guadalupe Mountains. M.S. thesis. Sul Ross State University. Alpine, TX. 138pp.

Mullet, T. C., and J. P. Ward, Jr. 2010. Microhabitat features at Mexican spotted owl nest and roost sites in the Guadalupe Mountains. Journal of Raptor Research 44: (in press).

Peery, M. Z., R. J. Gutiérrez, and M. E. Seamans. 1999. Habitat composition and configuration around Mexican spotted owl nest and roost sites in the Tularosa Mountains, New Mexico. Journal of Wildlife Management 63:36-43.

Peery, M. Z., R. J. Gutiérrez, R. Kirby, O. E. Ledee, and W. Lahaye. 2011. Climate change and spotted owls: potentially contrasting responses in the Southwestern United States. Global Change Biology 18:865–880. Doi:10.1111/j.1365-2486.2011.02564.x

Peterson, N. A. 2003. Evaluation of Mexican spotted owl roosting habitat on Fort Carson Military Reservation using Landsat 7 ETM+ satellite imagery and GIS modeling. Thesis, Colorado State University, Fort Collins, Colorado, USA.

Prather, J. W., H. M. Hampton, Y. Xu, B. G. Dickson, N. L. Dodd, E. N. Aumack, and T. D. Sisk. 2005. Modeling the effects of forest restoration treatments on sensitive wildlife taxa: a GIS-based approach. Pages 69-85 in: C. Van Riper and D. J. Mattson, editors. The Colorado Plateau II: Biophysical, Socioeconomic, and Cultural Research. University of Arizona Press, Tucson, USA.

Prather, J. W., R. F. Noss, and T. D. Sisk. 2008. Real versus perceived conflicts between restoration of ponderosa pine forests and conservation of the Mexican spotted owl. Forest Policy and Economics 10:140-150.

Rinkevich, S. E. 1991. Distribution and habitat characteristics of Mexican spotted owls in Zion National Park, Utah. Thesis, Humboldt State University, Arcata, California, USA.

Rinkevich, S. E., and R. J. Gutiérrez. 1996. Mexican spotted owl habitat characteristics in Zion National Park. Journal of Raptor Research 30:74-78.

Seamans, M. E., and R. J. Gutiérrez. 1995. Breeding habitat ecology of the Mexican spotted owl in the Tularosa Mountains, New Mexico. Condor 97:944-952.

Seamans, M. E. and R. J. Gutiérrez. 1999. Diet composition and reproductive success of Mexican spotted owls. Journal of Raptor Research 33:143-148.

Seamans, M. E., R. J. Gutiérrez, C. A. May, and M. Z. Perry. 1999. Demography of two Mexican Spotted Owl populations. Conservation Biology 13:744-754.

Seamans, M. E., R. J. Gutiérrez, and C. A. May. 2002. Mexican spotted owl (Strix occidentalis) population dynamics: Influence of climatic variation on survival and reproduction. Auk 119:321-334.

Stacey, P. B. 2010. Spotted Owl (Strix occidentalis). Pp. 597-621 in: Cartron, J-L. E. Raptors of New Mexico. University of New Mexico Press. Albuquerque. 710 pp.

Stacey, P. B., and A. Hodgson. 1999. Biological diversity in montane riparian ecosystems: The case of the Mexican spotted owl. Pages 204-210 in: D. M. Finch, J. C. Whitney, J. F. Kelly, and S. R. Loftin, editors. Rio Grande ecosystems: Linking land, water, and people. USDA Forest Service Proceedings RMRS-P-7.

Stacey, P. B., and M. Z. Peery. 2002. Population trends of the Mexican spotted owl in west-central New Mexico. Bulletin New Mexico Ornithological Society 30:42.

Sureda, M. and M. L. Morrison. 1998. Habitat use by small mammals in southeastern Utah, with reference to Mexican spotted owl management. Great Basin Naturalist 58:76-81.

Sureda, M. and M. L. Morrison. 1999. Habitat characteristics of small mammals in southeastern Utah. Great Basin Naturalist 59:323-330.

Swarthout, E. C. H., and R. J. Steidl. 2001. Flush responses of Mexican spotted owls to recreationists. Journal of Wildlife Management 65:312-317.

Swarthout, E. C. H., and R. J. Steidl. 2003. Experimental effects of hiking on breeding Mexican spotted owls. Conservation Biology 17:307-315.

Tarango, L. A., R. Valdez, P. J. Zwank, and M. Cardenas. 1997. Mexican spotted owl habitat characteristics in southwestern Chihuahua, New Mexico. Southwestern Naturalist 42:132-136.

Tarango, L. A., R. Valdez, F. Clemente, and G. Mendoza. 2001. Roost-site characteristics of Mexican spotted owls in Sierra Fria, Aguascalientes, Mexico. Journal of Raptor Research 35:165-168.

Urban, D., and T. Keitt. 2001. Landscape connectivity: A graph-theoretic perspective. Ecology 82:1205-1218.

Ward, J. P., Jr. 2001. Ecological responses by Mexican spotted owls to environmental variation in the Sacramento Mountains, New Mexico. Dissertation, Colorado State University, Fort Collins, Colorado, USA.

Ward, J. P., Jr., and Block, W. M. 1995. Mexican spotted owl prey ecology. Chapter 5:(1-48) in: USDI Fish and Wildlife Service, Recovery Plan for the Mexican spotted owl (Strix occidentalis lucida). Volume II - Technical supporting information. Albuquerque, New Mexico, USA.

Ward, J. P., Jr., and D. Salas. 2000. Adequacy of roost locations for defining buffers around Mexican spotted owl nests. Wildlife Society Bulletin 28: 688-698.

Ward, J. P., Jr., A. B. Franklin, S. E. Rinkevich, and F. Clemente. 1995. Distribution and abundance of Mexican spotted owls. Chapter 1:(1-14) in: USDI Fish and Wildlife Service, Recovery Plan for the Mexican spotted owl (Strix occidentalis lucida). Vol. II - Technical supporting information. USDI Fish and Wildlife Service. Albuquerque, New Mexico, USA.

White, G. C., A. B. Franklin, and J. P. Ward, Jr. 1995. Population biology. Chapter 2: 1-2 in: USDI Fish and Wildlife Service, Recovery Plan for the Mexican spotted owl (Strix occidentalis lucida). Volume II. Technical supporting information. Albuquerque, New Mexico, USA.

White, G. C., W. M. Block, J. L. Ganey, W. H. Moir, J. P. Ward, Jr., A. B. Franklin, S. L. Spangle, S. E. Rinkevich, J. R. Vahle, F. P. Howe, and J. L. Dick, Jr. 1999. Science versus political reality in delisting criteria for a threatened species: The Mexican Spotted Owl experience. Transactions North American Wildlife and Natural Resources Conference 64: 292-306.

Willey, D. W. 1995. Mexican spotted owls in canyonlands of the Colorado Plateau. Pages 330-331 in: E. T. LaRoe, G. S. Farris, C. E. Puckett, P. D. Doran, and M. J. Mac, editors. Our living resources: a report to the nation on the distribution, abundance, and health of U. S. plants, animals, and ecosystems. U. S. Department of the Interior –National Biological Service, Washington, D. C., USA.

Willey, D. W. 1998a. Movements and habitat utilization by Mexican spotted owls within the canyonlands of Utah. Dissertation, Northern Arizona University, Flagstaff, Arizona, USA.

Willey, D. W. and C. van Riper III. 1998. Ecology of Mexican spotted owls (Strix occidentalis lucida) in the canyonlands of southern Utah and potential relationships to the GSENM. Pages 219-228 in: Learning from the past: Grand Staircase – Escalante National Monument Science Symposium Proceedings. USDI Bureau of Land Management. Grand staircase – Escalante National Monument, Kanab, Utah, USA.

Willey, D. W. and C. van Riper III. 2000. First-year movements by juvenile Mexican spotted owls in the canyonlands of Utah. Journal of Raptor Research 34:1-7.

Willey, D. W. and C. van Riper III. 2007. Home range characteristics of Mexican spotted owls in the canyonlands of Utah. Journal of Raptor Research 41:10-15.

Willey, D. W., and R. V. Ward. 2004. Mexican spotted owl distribution and habitat within Grand Canyon National Park. Pages 328-334 in: Harmon, D., B. M. Kilgore, and G. E. Vietzke, editors. Protecting Our Diverse Heritage: The Role of Parks, Protected Areas, and Cultural Sites. (Proceedings of the 2003 George Wright Society/National Park Service Joint Conference.) The George Wright Society. Hancock, Michigan, USA.

Willey, D.W., and H.C. Willey. 2010. Ecology of small mammals within spotted owl nest areas in Grand Staircase-Escalante National Monument. Pages 463-480 in: Learning from the Land: Grand Staircase – Escalante National Monument Science Symposium Proceedings. USDI Bureau of Land Management. Grand Staircase – Escalante National Monument and Gran Staircase Escalante Partners. Kanab, Utah, USA.

Williams, S. O. III, and R. W. Skaggs. 1993. Distribution of the Mexican spotted owl (Strix occidentalis lucida) in Mexico. Unpublished report, New Mexico Department of Game and Fish, Santa Fe, New Mexico, USA.

Young, K. E., P. J. Zwank, R. Valdez, J. L. Dye, and L. A. Tarango. 1997. Diet of Mexican Spotted Owls in Chihuahua and Aguascalientes, Mexico. Journal of Raptor Research 31:376-380.

Young, K. E., R. Valdez, P. J. Zwank, and W. R. Gould. 1998. Density and roost site characteristics of spotted owls in the Sierra Madre Occidental, Chihuahua, Mexico. Condor 100:732-736.