Connect With Us
Eastern Massasauga (Sistrurus catenatus)
The eastern massasauga is a small, thick-bodied rattlesnake that lives in shallow wetlands and adjacent uplands in portions of Illinois, Indiana, Iowa, Michigan, Minnesota, New York, Ohio, Pennsylvania, Wisconsin, and Ontario. The eastern massasauga has been declining over the past three decades due to loss and fragmentation of its wetland habitat. Throughout its range, biologists have confirmed that less than half of the eastern massasauga’s historical populations still exist. We know of 558 historical populations, of which 211 have been lost and the status of 84 is uncertain – with the likelihood that many of those populations have also been lost. We have information indicating that 267 of the historical populations still exist today. Most of those populations are in Michigan and Ontario, Canada. New York, Pennsylvania, Ohio, Indiana, Illinois, Wisconsin and Iowa have fewer populations.
Final Rule to List as Threatened
The U.S. Fish and Wildlife Service listed the eastern massasauga rattlesnake (Sistrurus catenatus) as threatened under the Endangered Species Act. We also determined that designating critical habitat for the eastern massasauga is not prudent.
The Service listed the eastern massasauga as threatened because of loss of populations throughout its range, declines in the number of individuals within those populations and the fact that threats will continue to cause declines into the future. If we continue to lose eastern massasauga populations, the species is likely to face extinction in the future.
We prepared a Species Status Assessment to assess the eastern massasauga’s current and projected future ability to survive. The analysis predicts a continuing decline in the number of eastern massasauga populations. We know that 38 percent of historical populations have been lost as of 2014 and the status of another 15 percent is uncertain. Our analysis projects a 90 percent reduction in number of populations over the next 50 years. The southwestern portion of the snake’s range will see the most severe declines with a predicted 97 percent loss of historical populations over the next 50 years. In addition to the loss of populations, we expect the extent of species’ range will shrink by more than 80 percent over the next 50 years as populations are lost.
Final Rule (Federal Register Sept. 30, 2016)
Species Status Assessment (117-page PDF ; 2.4MB)
Life History and Ecology
Live and Let Live - Oakland County, Michigan Blog
Species Spotlight: Eastern Massasauga - USFWS Chicago Field Office
Eastern Massasauga - Michigan Society of Herpetologists
Species Survival Plan
AZA Species Survival Plan - A Species Survival Plan® is a collaborative science-based management program of the Association of Zoos and Aquariums (AZA).
Conservation and Research
Managing for Massasaugas - Edward Lowe Foundation | Land Stewardship. 4-page PDF. 2012
Species Action Plan - Pennsylvania Fish and Boat Commission (PDF). June 2011
Learning to Live with the Eastern Massasauga Rattlesnake: Expanding Outreach and Education in Southern Michigan Dec. 31, 2009. 171-page PDF
Spotlight Species Action Plan October 2009. 9-Page PDF
Restoring Southeast Michigan’s High Diversity Landscapes Through Collaborative Stewardship – Hillsdale, Jackson, Lenawee, Oakland, and Washtenaw Counties, Michigan. Private Stewardship Grant (May 2007):
Reforestation and Wetland Restoration for Permanent Native Habitat in the St. Joseph River Watershed – Hillsdale County, Michigan; Defiance and Williams Counties, Ohio; Allen, Dekalb, and Noble Counties, Indiana Private Stewardship Grant. May 2007
Molecular Diversity among Massasauga Rattlesnakes: Nuclear Intron Analyses S6 Grant Project 2006
Rome State Nature Preserve Candidate Conservation Agreement with Assurances Ashtabula County, Ohio. August 2006
Survey and Management Guidances
A Handbook for Land Managers (PDF 1.2 MB)
Archives: Chronological list of previous Federal Register publications, with associated information materials, and other actions pertaining to the Endangered Species Act status of the eastern massasauga.
Last updated: April 5, 2017