Ursus arctos nelsoni (Merriam, 1914)

Mexican grizzly (bear), Mexican silver grizzly (bear), South-west grizzly (bear)



Taxonomy & Nomenclature

No longer considered a valid taxon (Ceballos, 2014).


Conservation Status

Invalid (synonym)

Last record: 1962 (Goodwin & Goodwin, 1973); 1964?



Mexico (Baja California, Chihuahua, Coahuila & Durango)


Biology & Ecology










Brown, David E. (1985). The Grizzly in the Southwest: Documentary of an Extinction. University of Oklahoma Press. 280 pp.

Ceballos, Gerardo (ed.). (2014). Mammals of Mexico. Baltimore, Maryland: Johns Hopkins University Press.

Day, David. (1981). The Doomsday Book of Animals: A Natural History of Vanished Species. New York, N.Y.: The Viking Press.

Goodwin, Harry A. and Goodwin, J. M. (1973). List of mammals which have become extinct or are possibly extinct since 1600. Int. Union Conserv. Nat. Occas. Pap. 8: 1-20.

Hall, E. R., and K. R. Kelson. 1959. The mammals of North America. Ronald Press Co., New York, 1:1-546; 2:547-1083 + 79.

Johnson, A. S. (1975a). Donde Esta del Oso Plateado: Search for the Mexican Grizzly. Defenders of Wildlife 50(3): 242-245.

Johnson, A. S. (1975b). Donde Esta del Oso Plateado: Search for the Mexican Grizzly. Defenders of Wildlife 50(5): 436-439.

Jonkel, C., Kisen, S., Rockwell, D. and Dominguey, P. (1977). Status of the Mexican Grizzly. University of Montana BGP Spec. Report No. 6.

Joslin, Paul and Maryanka, Daphne. (1968). Endangered Mammals of the World: Report on Status and Action Treatment. IUCN Publications, New Series, Supplementary Paper No. 13: 34 pp.

Koford, C. B. (1969). The last of the Mexican Grizzly Bear. IUCN Bulletin 2(12): 94.

Lee, L. C. and Thier, T. J. (1979). Mexican Grizzly Bear studies. University of Montana BGP Spec. Report No. 32.

Leopold, A. Starker. (1959). Wildlife of Mexico: The Game Birds and Mammals. Berkeley: University of California Press.

Leopold, A. Starker. (1967). Grizzlies of the Sierra del Nido. Pacific Discovery 20(5): 30-32.

McTaggart Cowan, I. (1964). Threatened species of mammals in North America, pp. 17-21. In: Moore, J. A. (ed.). Proceedings of the 16th International Congress of Zoology 8: The Protection of Vanishing Species. Washington: 16th International Congress of Zoology.

Rausch, R. L. (1963). Geographic variation in size in North American Brown bears Ursus arctos L., as indicated by condylobasal length. Can. J. Zool. 41: 33-45.

Thornback, Jane and Jenkins, Martin (compilers). (1982). The IUCN Mammal Red Data Book. Part 1: Threatened Mammalian Taxa of the Americas and the Australasian Zoogeographic Region (Excluding Cetacea). Gland, Switzerland: IUCN. 516 pp.

Trevino, Jose C. and Jonkel, Charles. (1986). Do Grizzly Bears Still Live in Mexico?, pp. 11-13. In: Bears: Their Biology and Management Vol. 6, A Selection of Papers from the Sixth International Conference on Bear Research and Management, Grand Canyon, Arizona, USA, February 1983. [Abstract]


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