Newton, I., I. Wyllie, and A. Asher. 1991. Mortality causes in British Barn Owls Tyto alba with a discussion of aldrin-diedrin poisoning. Ibis 133: 162-169.

Russell, R. W., et al. 1991. A visual study of migrating owls at Cape May Point, New Jersey. Condor 93:55-61.

Thompson, D. B., J. H. Brown, and W. D. Spencer. 1991. Indirect facilitation of granivorous birds by desert rodents: experimental evidence from foraging patterns. Ecology 72(3):852-683.

U.S. Fish and Wildlife Service (USFWS). 1991. Endangered and threatened wildlife and plants; animal candidate review for listing as endangered or threatened species. Proposed Rule. Federal Register. 56(225):58804-36.

DeBruin, E. 1991. Field survey to Fort Stanton ACEC - Stop #20 24 May, 1991

Horton, J. and C. Persichetty. 1991. Field survey to Capitan Mts. - Pierce Canyon Arroyo at Forest Rd. 57, 23 May 1991.

Muldavin, E. 1991. White Sands Missile Range Vegetation Communities Survey.

Avise, J. C., C. D. Ankney, and W. S. Nelson. 1991. Mitochondrial gene trees and the evolutionary relationship of mallard and black ducks. Evolution 44:1109-1119.

Burger, J., and R. T. Zappalorti. 1991. Nesting behavior of pine snakes (Pituophis m. melanoleucus) in the New Jersey Pine Barrens. J. Herpetol. 25:152-160.

Garrott, R. A. 1991b. Sex ratios and differential survival of feral horses. J. Anim. Ecol. 60:929-937.

Dunmire, W.W. 1991. T & E and sensitive plant survey: San Pedro ACEC, Socorro Resource Area, Bureau of Land Management. Unpublished report for BLM by TNC. 11 p + maps + photos.

Johnson, F. A., et al. 1991. Distribution, abundance, and habitat use by mottled ducks in Florida. J. Wildl. Manage. 55:476-482.

Nehlsen, W., J. E. Williams, and J. A. Lichatowich. 1991. Pacific salmon at the crossroads: stocks at risk from California, Oregon, Idaho, and Washington. Fisheries 16(2):4-21.

Hoeh, W.R. 1991. The evolution and consequences of simultaneous hermaphroditism in the freshwater mussel genus Utterbackia (Bivalvia: Unionidae). Ph.D. Dissertation, Biology, University of Michigan, Ann Arbor, Michigan. 97 pp.

Rosen, P. C. 1991. Comparative ecology and life history of the racer (Coluber constrictor) in Michigan. Copeia 1991:897-909.

Sivinski, R. 1991. Annual Section 6 performance report monitoring endangered plants (job 1). Unpublished report for U.S. Fish and Wildlife Service, Albuquerque, NM. 135 p + maps.

Walker, J. M., et al. 1991. Activity, temperature, age, size and reproduction in the parthenogenetic whiptail lizard Cnemidophorus dixoni in the Chinati Mountains in Trans-Pecos Texas. Am. Midl. Nat. 126:256-268.

Ownbey, G. B., and T. Morley. 1991. Vascular plants of Minnesota: A checklist and atlas. University of Minnesota Press, Minneapolis.

Buehler, D. A., et al. 1991d. Nonbreeding bald eagle communal and solitary roosting behavior and roost habitat on the northern Chesapeake Bay. J. Wildlife Management 55:273-281.

Ewert, D. N., and R. A. Askins. 1991. Flocking behavior of migratory warblers in winter in the Virgin Islands. Condor 93:864-868.

Jacobson, E. R., et. al. 1991. Chronic upper respiratory disease of free-ranging desert tortoises (Xerobates agassizii) in Las Vegas Valley, Nevada. Journal of Wildlife diseases. 27(2):296-316.

Morales, J. C., S. W. Balllinger, J. W. Bickham, I. F. Greenbaum, and D. A. Schlitter. 1991. Genetic relationships among eight species of Eptesicus and Pipistrellus (Chiroptera: Vespertilionidae). Journal of Mammalogy 72:286-291.

Rieseberg, L.H. 1991. Hybridization in rare plants: insights from case studies in CERCOCARPUS and HELIANTHUS. In Falk, D.E. and K.E. Holsinger, eds. Genetics and conservation of rare plants. Oxford University Press.

Zink, R. M., D. L. Dittman, and W. L. Rootes. 1991b. Mitochondrial DNA variation and the phylogeny of ZONOTRICHIA. Auk 108:578-584.

Clayton, P. 1991. Field survey to Ball Ranch - Stop #13 on 23 July 1991.

DeBruin, E. 1991. Field survey to Fort Stanton ACEC - Stop #41 28 May, 1991.

DeBruin, E. 1991. Field survey to Farmington Resource Area- ACEC Area #13 on 25 April 1991.

Alldredge, A. W., R. D. Deblinger, and J. Peterson. 1991. Birth and fawn bed site selection by pronghorns in a sagebrush-steppe community. J. Wildl. Manage. 55:222-227.

Burns, R. J., H. P. Tietjen, and G. E. Connolly. 1991. Secondary hazard of Livestock Protection Collars to skunks and eagles. J. Wildl. Manage. 55:701-704.

Einemann, L. 1991. A nesting report of a Wilson's Phalarope in Lancaster County. Nebraska Bird Review 59:59-61.

Kraus, F., P.K. Ducey, P. Moler,. and M.M. Miyamoto. 1991. Two new triparental unisexual Ambystoma from Ohio and Michigan. Herpetologica. 47:429-439.

Stuart, J. N. 1991. Cnemidophorus exsanguis. Cat. Am. Amph. Rept. 516.1-516.4.

Mattson, D. J., et al. 1991b. Bear feeding activity at alpine insect aggregation sites in the Yellowstone ecosystem. Canadian J. Zoolgoy 69:2430-2435.

Ridgway, M. S., J. A. MacLean, and J. C. MacLeod. 1991a. Nest-site fidelity in a centrarchid fish, the smallmouth bass (Micropterus dolomieui). Canadian Journal of Zoology 69:3103-3105.

Gonzalez, M., S. Gonzalez, and Y. Herrera. 1991. Listados floristicos de Mexico. IX. Flora de Durango. Instituto de Biologia, Universidad Nacional Autonoma de Mexico, Mexico, D.F. 167 pp.

Flanagan, P. (1991) 1991 Mexican Spotted Owl Inventory Form. Questa Ranger District, Carson National Forest, USFS. 41 p.

Locklear, J.H. 1991. The status of Asclepias uncialis green in eastern Co and NE New Mexico. Unpubl report to the Co Field Office of TNC. 55 p + photos + maps.

Sanchez, B. (1991) Formal Spotted Owl Monitoring, Management Territoty 0602007. Silver City Ranger District, Gila National Forest, USFS. 7 p.

Brozka, R.J. 1991. Progress report, 1988-1990: Land Condition-Trend Analysis Program, White Sands Missile Range, New Mexico. Prepared by U.S. Army Corps of Engineers, Construction Engineering Research Laboratory, Environmental Division. October 1991.

Howard, M. 1991. Sensitive threatened and endangered plant data form. May 8, 1991.

Paul, L. (1991) Unpublished Letter to Forest Supervisor, Subject: Peregrine Falcon Eyrie (Code Name Agua Dulce). Lincoln Supervisor's Office, Lincoln National Forest, USFS. 3 p.

DeBruin, E. 1991. Special plant survey form, New Mexico for Draba standleyi.

American Ornithologists' Union (AOU) . 1991. Thirty-eighth Supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 108:750-754.

DeBruin, E. 1991. Field survey to Fort Stanton ACEC - Stop #13 27 May, 1991.

Margules, C.R. and M.P. Austin. Eds. 1991. Nature conservation: cost effective biological surveys and data analysis. Csiro, Australia.

DeBruin, E. 1991. Field survey to Fort Stanton ACEC - Stop #3 on 22 May 1991 - Mammillaria heyderi.

DeBruin, E. 1991. Field survey to Tularosa Mts - Long canyon on 23 July 1991.

DeBruin, E. 1991. Field survey to Farmington Resource Area-plot #21 on 8 May 1991.

DeBruin, E. 1991. Field survey to Farmington Resource Area - Kitten Canyon stop #9 on 5 May 1991.

Burger, J., and M. Gochfeld. 1991. Reproductive vulnerability: parental attendance around hatching in roseate (STERNA DOUGALLII) and common (S. HIRUNDO) terns. Condor 93:125-129.

DeBlieu, J. 1991. Remodeling the condor. New York Times Magazine, 18 November 1991.

Gibbs, J. P. 1991. Spatial relationships between nesting colonies and foraging areas of great blue herons. Auk 108:764-770.

Advanced Sciences, Inc. 1991. Final preliminary draft Environmental Impact Statement (affected environment and non-EMP related environmental and socioeconomic consequences sections) for the relocation of the Woodbridge Research Facility Electromagnetic Pu

Manning, R. W. and J. R. Goetze. 1991. First record of the elf owl (MICRATHENE WHITNEYI WHITNEYI) east of the Pecos River, Texas. Texas Journal of Science 43:103-104.

Helmers, D.L. 1991. Habitat use by migrant shorebirds and invertebrate availability in a managed wetland complex. M.S. Thesis, Univ. of Missouri Columbia. 135pp.

Reed, S. et al. 1991. Unpublished field notes from Astragalus kerrii/Echinocereus fendleri var kuenzleri survey on 22 May- 31 May 1991.

Falvey, B. 1991. Gilia formosa sites on Horn Canyon Quad. BLM, Farmington, NM.

Nichols, J. D. 1991. Science, population ecology, and the management of the American black duck. J. Wildl. Manage. 55:790-799.

Sauer, J. R., and J. B. Bortner. 1991. Population trends from the American woodcock singing-ground survey, 1970-1988. J. Wildl. Manage. 55:300-312.

Thompson, C.W. 1991d. The sequence of molts and plumages in painted buntings and implications for theories of delayed plumage maturation. Condor 93:209-235.