About the Authors

Dustin A. Wood

Roles Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Validation, Visualization, Writing – original draft, Writing – review & editing

dawood@usgs.gov

Affiliation U.S. Geological Survey, Western Ecological Research Center, San Diego Field Station, San Diego, California, United States of America

Jonathan P. Rose

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Software, Validation, Writing – original draft, Writing – review & editing

Affiliation U.S. Geological Survey, Western Ecological Research Center, Santa Cruz Field Station, Santa Cruz, California, United States of America

Brian J. Halstead

Roles Conceptualization, Formal analysis, Funding acquisition, Methodology, Project administration, Writing – original draft, Writing – review & editing

Affiliation U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, California, United States of America

Ricka E. Stoelting

Roles Data curation, Resources, Writing – review & editing

Affiliation Swaim Biological Incorporated, Livermore, California, United States of America

Karen E. Swaim

Roles Resources, Writing – review & editing

Affiliation Swaim Biological Incorporated, Livermore, California, United States of America

Amy G. Vandergast

Roles Conceptualization, Formal analysis, Funding acquisition, Writing – original draft, Writing – review & editing

Affiliation U.S. Geological Survey, Western Ecological Research Center, San Diego Field Station, San Diego, California, United States of America

Competing Interests

Swaim Biological, Inc collected Thamnophis sirtalis tetrataenia tissues between the years 2005 – 2015 that were provided as an in-kind service and these tissues were utilized in this study. Site data from a previously published study [35], which was partially funded by Swaim Biological, Inc, were also used in the present study. This does not alter our adherence to PLOS ONE policies on sharing data and materials.