Status and Risk of Extinction for Westslope Cutthroat Trout in the Upper Missouri River Basin, Montana
- 1 November 1997
- journal article
- Published by Oxford University Press (OUP) in North American Journal of Fisheries Management
- Vol. 17 (4) , 1158-1172
- https://doi.org/10.1577/1548-8675(1997)017<1158:saroef>2.3.co;2
Abstract
Westslope cutthroat trout Oncorhynchus clarki lewisi now occupy less than 5% of the subspecies' historical range within the upper Missouri River drainage in Montana. We assessed the risk of extinction for 144 known populations inhabiting streams within federally managed lands in the upper Missouri River basin using a Bayesian viability assessment procedure that estimates probability of persistence based on subjective evaluation of population survival and reproductive rates as influenced by environmental conditions. We first customized this model using estimates of demographic parameters from the literature and field data. Each population was classified into one of three risk groups based on their Bayesian probability of persistence over 100 years (p 100). Most (71 %) of the 144 populations had a very high predicted risk of extinction (p 100 ≤ 50%), 19% exhibited a high risk (50% < p 100 ≤ 80%), and 10% had a moderate risk (80 < p100 ≤ 95%). Higher average predictions of p 100 were consistently as...Keywords
This publication has 0 references indexed in Scilit: