Catastrophic wildfire and number of populations as factors influencing risk of extinction for Gila trout (Oncorhynchus gilae)

Authors

D. Kendall Brown, Oklahoma State University, Stillwater, Oklahoma
Anthony A. Echelle, Oklahoma State University, Stillwater, Oklahoma
David L. Propst, New Mexico Department of Game and Fish, Santa Fe, New Mexico
James E. Brooks, U.S. Fish and Wildlife Service, Albuquerque, New Mexico
William L. Fisher, Oklahoma State University, Stillwater, Oklahoma

Abstract

We used the computer program RAMAS to explore the sensitivity of an extinction-risk model for the Gila trout (Oncorhynchus gilae) to management of wildfires and number of populations of the species. The Gila trout is an endangered salmonid presently restricted to very few headwaters of the Gila and San Francisco river tributaries in southwestern New Mexico. Life history data for 10 extant populations were used to examine sensitivity of the species viability to changes in a variety of factors including population size, fecundity, life stage structure, number of populations, severity and probability of forest fires, and a regulated fishery. The probability and severity of forest fires and number of populations had the greatest effect on viability. Results indicate that successful conservation of Gila trout requires establishment of additional populations and reduction of the severity of forest fires through a program incorporating more frequent, but less severe, fires.

Recommended Citation

Brown, D. Kendall; Echelle, Anthony A.; Propst, David L.; Brooks, James E.; and Fisher, William L. (2001) "Catastrophic wildfire and number of populations as factors influencing risk of extinction for Gila trout (Oncorhynchus gilae)," Western North American Naturalist: Vol. 61: No. 2, Article 2.
Available at: https://scholarsarchive.byu.edu/wnan/vol61/iss2/2