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Herpetological monitoring and assessment on the Trinity River, Trinity County, California—Final report

Open-File Report 2016-1089
Prepared in cooperation with the Trinity River Restoration Program
By:  and 
https://doi.org/10.3133/ofr20161089

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Abstract

The primary goal of the Trinity River Restoration Program is to rehabilitate the fisheries on the dam-controlled Trinity River. However, maintaining and enhancing other wildlife populations through the restoration initiative is also a key objective. Foothill yellow-legged frogs (Rana boylii) and western pond turtles (Actinemys marmorata) have been identified as important herpetological species on which to focus monitoring efforts due to their status as California state-listed species of concern and potential listing on the U.S. Endangered Species List. We developed and implemented a monitoring strategy for these species specific to the Trinity River with the objectives of establishing baseline values for probabilities of site occupancy, colonization, and local extinction; identifying site characteristics that correlate with the probability of extinction; and estimating overall trends in abundance. Our 3-year study suggests that foothill yellow-legged frogs declined in the probability of site occupancy. Conversely, our results suggest that western pond turtles increased in both abundance and the probability of site occupancy. The short length of our study period makes it difficult to draw firm conclusions, but these results provide much-needed baseline data. Further monitoring and directed studies are required to assess how habitat changes and management decisions relate to the status and trend of these species over the long term.

Suggested Citation

Snover, M.L., and Adams, M.J., 2016, Herpetological monitoring and assessment on the Trinity River, Trinity County, California—Final report: U.S. Geological Survey Open-File Report 2016-1089, 93 p., http://dx.doi.org/10.3133/ofr20161089.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Methods
  • Data Analysis
  • Results
  • Discussion
  • Monitoring Protocols
  • Acknowledgments
  • References Cited
  • Appendixes A–N
Publication type Report
Publication Subtype USGS Numbered Series
Title Herpetological monitoring and assessment on the Trinity River, Trinity County, California—Final report
Series title Open-File Report
Series number 2016-1089
DOI 10.3133/ofr20161089
Year Published 2016
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Forest and Rangeland Ecosystem Science Center
Description vi, 93 p.
Country United States
State California
County Trinity County
Other Geospatial Trinity River
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details