Reevaluating Cascades Frog Status in Oregon

Project ID: F19AP00369

Federal Agency: U.S. Fish and Wildlife Service

Partner Institution: Oregon State University

Fiscal Year: 2019

Initial Funding: $20,921

Total Funding: $20,921

Principal Investigator: Duarte, Adam

Agreement Technical Representative: Dillon, Jeff

Abstract: Funds under this award are to be used to provide up-to-date information on the status and trends of Cascades frog in Oregon. Specifically, this work will estimate occupancy of Cascades frog in Oregon and factors that influence species detectability, use estimates of detection probabilities and historic survey data to retroactively estimate occupancy of Cascades frog in Oregon, and compare the estimates to qlantify change in the species’ distribution in Oregon.

The Cascades frog is a pond breeding amphibian that was historically widespread in the motmtains of the Pacific Northwest, but species declines in California and Oregon have been documented. The species is currently being considered for federal protection under the Endangered Species Act. However, information concerning the status of the species is 15 years old, previous efforts in California did not consider the effect of species detectability on their inferences, and previous efforts in Oregon restricted their findings to site
use probabilities rather than occupancy probabilities. Thus, managers are being asked to evaluate whether the Cascades frog qualifies for federal protection without having up-to-date information on the status of the species and with information that may not be the ideal information in which to base a listing decision on.
The Recipient Will:

• develop a model to analyze. recently collected (2018-2019) detection/non-detection data (with replicate surveys within a season) to estimate occupancy of Cascades frog in Oregon and factors that influence species detectability,
use estimates concerning detection probabilities to retroactively estimate occupancy of Cascades frog in Oregon using detection/non-detection data (without replicate surveys within a season) collected in 2001-2004, and
compare estimates of Cascades frog occupancy in 2001-2004 and 2018-2019 to quantify change in occupancy across the ca. 15 years in Oregon. submit a draft manuscript (peer-reviewed journal ready) no later than 31 December 2020. The manuscript will include thorough documentation of all models, code, and model output.