An updated assessment of status and trend in the distribution of the Cascades frog (Rana cascadae) in Oregon, USA

Herpetological Conservation and Biology
By: , and 



Conservation efforts need reliable information concerning the status of a species and their trends to help identify which species are in most need of assistance. We completed a comparative evaluation of the occurrence of breeding for Cascades Frog (Rana cascadae), an amphibian that is being considered for federal protection under the U.S. Endangered Species Act. Specifically, in 2018–2019 we resurveyed 67 sites that were surveyed approximately 15 y prior and fit occupancy models to quantify the distribution of R. cascadae breeding in the Cascade Range, Oregon, USA. Furthermore, we conducted a simulation exercise to assess the power of sampling designs to detect declines in R. cascadae breeding at these sites. Our analysis of field data combined with our simulation results suggests that if there was a decline in the proportion of sites used for R. cascadae breeding in Oregon, it was likely a < 20% decline across our study period. Our results confirm that while R. cascadae detection probabilities are high, methods that allow the sampling process to be explicitly modeled are necessary to reliably track the status of the species. This study demonstrates the usefulness of investing in baseline information and data quality standards to increase capacity to make similar comparisons for other species in a timeframe that meet the needs of land managers and policy makers.

Study Area

Publication type Article
Publication Subtype Journal Article
Title An updated assessment of status and trend in the distribution of the Cascades frog (Rana cascadae) in Oregon, USA
Series title Herpetological Conservation and Biology
Volume 16
Issue 2
Year Published 2021
Language English
Publisher Herpetological Conservation and Biology
Contributing office(s) Forest and Rangeland Ecosystem Science Center
Description 13 p.
First page 361
Last page 373
Country United States
State Oregon
Other Geospatial Cascade Range
Google Analytic Metrics Metrics page
Additional publication details