Date of Award


Document Type


Degree Name

Master of Science


College of Arts and Sciences


Biology, MS

First Advisor

Daniel Gonzalez-Socoloske

Second Advisor

Peter J. Lyons

Third Advisor

James L. Hayward


The Eastern Massasauga rattlesnake (Sistrurus catenatus; EMR) is a small robust pit viper currently found in nine states and the province of Ontario, Canada. Wetland habitats have experienced significant destruction and fragmentation by humans; as a result, the current distribution of the EMR is a fraction of its historic distribution. For this reason, the EMR has been federally listed as threatened. In general, little is known about the current distribution of this rattlesnake (in the southwest corner of Michigan, the size of local populations or their stability and genetic diversity. Much of this knowledge is based upon historical data. My purpose was to update the available information on the current status in Berrien County and one Van Buren County site. This was done through presence/absence surveys, evaluation of potential threats at each site visited and genetic analysis at the haplotype level. Through my field surveys I confirmed presence of EMRs at 3 of the 5 historic locations surveyed. Current threats at these sites include human encroachment, road traffic, and general health of the particular habitat. Despite the relatively small sample size and isolated populations in these counties, the haplotype diversity discovered appears to be high in comparison to the rest of their range.

Subject Area

Rattlesnakes--Michigan--Berrien County; Sistrurus--Michigan--Berrien County; Eastern massasauga--Michigan--Berrien County


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