A wild eastern massasauga rattlesnake
A wild eastern massasauga rattlesnake


Habitat loss has caused this shy species to become endangered through much of its range, including Illinois. Lincoln Park Zoo works with partners across the country to guide its recovery.


Cryptic coloration helps the eastern massasauga rattlesnake blend in expertly among the marshes, fields, and prairies where it makes its home. But camouflage isn’t the only reason this snake is hard to spot in the wild. Habitat loss over the last three decades has resulted in this shy species becoming endangered throughout much of its range in the Great Lakes region, including Illinois and parts of and Canada. Lincoln Park Zoo is working with partners across the country to guide the recovery of this rare reptile.

Studying Michigan’s Massasaugas

In a project managed by the Eastern Massasauga Rattlesnake Species Survival Plan® (SSP) and Lincoln Park Zoo, more than 20 zoos, the Edward Lowe Foundation, Northern Illinois University, and several wildlife agencies are studying a healthy massasauga population in Michigan.

Since 2009, more than 900 of these rattlesnakes have been captured, individually identified, and re-released at study sites in Michigan. By monitoring them over time, scientists are able to determine the characteristics that help them thrive, which in turn informs massasauga conservation plans.


Modeling the Species’ Future

Assessing a species’ health across its range is often difficult, as each local land manager or conservation agency might measure “health” using a different metric. In a collaboration with the U.S. Fish and Wildlife Service and massasauga experts across the United States and Canada, Lincoln Park Zoo Senior Director of Population Ecology Lisa Faust, Ph.D., used a computer model to try to improve understanding of massasuaga status across its range from 2008-2011.

Faust built a computer model of massasauga biology, including birth and death rates and the threats across the range that might affect them, such as the effects of forest succession or road mortality. Using data collected from 65 sites across every state and province in the species’ range, the model helped determine the relative status of the species at each site. This modeling effort helped guide conservation action for the species, and its results were used to inform the Species Status Assessment and the eventual decision by the U.S. Fish and Wildlife Service to list the massasauga as “Threatened” under the federal Endangered Species Act in 2016.



U.S. Fish and Wildlife Service

Edward Lowe Foundation

Eastern Massasauga Rattlesnake SSP®

Eric Hileman, Ph.D., Mississippi State University


Senior Director of Population Ecology
Curator of Small Mammal-Reptile House, Children’s Zoo, Camel & Zebra
Population Analyst
Alexander Center for Applied Population Biology
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