Graduation Date

Spring 2024

Document Type



Master of Science degree with a major in Biology

Committee Chair Name

Sharyn Marks

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Ho Yi Wan

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

James Graham

Third Committee Member Affiliation

HSU Faculty or Staff

Fourth Committee Member Name

Daniel Barton

Fourth Committee Member Affiliation

HSU Faculty or Staff


Habitat suitability modeling, Guided surveys, Dunn's salamander, Plethodon dunni, MaxEnt, GLM

Subject Categories



Habitat suitability models were utilized to direct survey efforts for Plethodon dunni in Northern California. Two models were created, one using traditional statistical methods (GLM or Generalized Linear Modeling) and the other using a machine learning method (MaxEnt or Maximum Entropy modeling). Plots were selected from areas of agreement and disagreement between the models to carry out presence surveys. The MaxEnt model yielded better predictions than the GLM model. The two models had three variables in common (annual temperature range, precipitation of driest month, and precipitation seasonality) and predicted suitable habitat within the known range of P. dunni. The surveys confirmed the models' predictions by detecting the presence of P. dunni at 13 out of 20 plots. Plethodon dunni was detected at historical locations along Rowdy Creek Road and North Bank Road, north of the Smith River in Del Norte County, California. This study also filled a gap in the record of P. dunni observations between the Oregon-California border and Rowdy Creek Road. In conclusion, habitat suitability models are a valuable tool for selecting suitable habitat locations and directing survey efforts, and in this study, they were successfully applied to P. dunni.

Citation Style


Included in

Biology Commons


Thesis/Project Location


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