Bradford D. Hollingsworth, Ph.D.

Curator of Herpetology  

Brad has served as the department’s curator since 2000, after serving as a postdoctoral fellow, guest curator of exhibits, expedition lead herpetologist, museum store employee, and volunteer. He received his doctorate from Loma Linda University and obtained both his M.S. and B.S. from San Diego State University. Brad’s research focuses on the evolution and biogeography of the herpetofauna of Baja California and its associated islands. Brad is also an Adjunct Professor at San Diego State University where he regularly teaches in the Biology Department.


Melissa A. Stepek, M.S.

GIS Specialist and Contract Manager 

Melissa joined the museum in 2008 as the department’s NSF Collections Project Manager, and now serves as the department’s GIS Specialist and Contract Manager. She earned her M.S. in Biology from East Stroudsburg University and her B.A. in Anthropology from the University of California, San Diego. Melissa has over fourteen years of wildlife and GIS field experience with a wide variety of agencies. She has a broad range of zoological and collection interests, but her main focus is herpetology. Her specialty is the behavioral ecology of semi-aquatic freshwater turtles.


Research Associates

Charles Crumly, Ph.D. (University of California Press, Berkeley) 

Lee Grismer, Ph.D. (Professor of Biology, La Sierra University)

William Presch, Ph.D. (California Desert Studies Consortium, Department of Biological Sciences, CSU Fullerton)

Tod Reeder, Ph.D. (San Diego State University)


Departmental Associates

Mr. Clark Mahrdt (Southwest Biological Associates)

Mr. Dick Schwenkmeyer (Mesa Community College, Retired)

Angelo Soto-Centeno (Florida Museum of Natural History)

Dustin Wood (United States Geological Survey)



The normal day-to-day accomplishments of the department would not be feasible without our core group of volunteers. Volunteer projects include making fieldguide webpages, digital mapping, fieldwork, and collections renovation.

The department is currently not accepting new volunteers. 

Be sure to check out other volunteer opportunities on the  Current Needs page. We offer a wide range of activites for individuals interested in natural history.