SUSAN B. PARSONS NSF Graduate Fellow
Thesis Title:
Landscape genetics of Great Basin rattlesnakes on the upper Snake River Plain.

Research Advisor:
Dr. Charles R. Peterson & Dr. Marjorie D. Matocq

Teacher Partner:
T. Paul Davids

Degree Sought:
Masters of Science

University Department and/or Lab:
Biological Sciences, Herpetology Laboratory

Research Focus:
Creating landscape-mediated gene flow models using GIS and microsatellite DNA technologies.

Description of Research:
Landscape genetics, made possible by advances in Geographic Information System (GIS) and microsatellite DNA imaging technologies, combines landscape ecology and population genetics to explain how landscape characteristics affect gene flow and population structure (Manel et al. 2003, Storfer 2006). I intend to model how landscape variables and levels of disturbance affect population structure and vagility in Great Basin Rattlesnakes, Crotalus viridis oreganus, in the shrub-steppe ecosystem of the Upper Snake River Plain in eastern Idaho. Sagebrush-steppe ecosystems are among the most endangered terrestrial ecosystems in North America (Noss et al. 1995), largely due to extensive habitat conversion resulting from interactions between livestock grazing, exotic plant species introduction, and increased wildfire frequency (Whisenant 1990). I will obtain rattlesnake DNA samples from relatively undisturbed shrub-steppe habitat on the Idaho National Laboratory (INL), in the form of blood or scales clips, and from dens found outside the INL on highly disturbed BLM managed lands. Fifteen microsatellite loci developed for midget-faded, timber, and New Mexico ridge-nosed rattlesnakes will allow me to generate multilocus genotypes for at least 300 individuals across the study area. Landscape variables used for modeling gene flow will include distances between dens, topography, suitability of soil substrate for denning, ephemeral water sources, cover types, burn areas, grazing allotment, and infrastructure.

Profile date: April 2007