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In search of eastern massasauga rattlesnake near and far

Eastern massasauga rattlesnake by Mike Redmer/USFWS.

Eastern massasauga rattlesnake. Photo by Mike Redmer/USFWS.

By Matt Mangan and Kristen Lundh
Illinois-Iowa Ecological Services Field Office

In the spring of 2018, staff from the Illinois-Iowa Field Office took to the field across the Midwest in search of the threatened eastern massasauga rattlesnake. At Carlyle Lake, staff assisted the Illinois Natural History Survey with their annual monitoring efforts. The Carlyle Lake population is the largest and most viable population of eastern massasaugas in Illinois and is found primarily in fragmented grassland habitats on federal and state lands managed for the species. In all, the field office helped the survey staff locate nine individual eastern massasauga rattlesnakes in one day. Their work included discovery of potentially the largest eastern massasauga ever collected, at 31 inches long and 1.3 pounds!

The Illinois-Iowa office also took part in the annual survey of the population at the Edward Lowe Foundation properties in Michigan. Since 2009, members of the Eastern Massasauga Rattlesnake Species Survival Plan group, including the Lincoln Park Zoo, the Edward Lowe Foundation, Northern Illinois University and more than 20 member zoos in the group, have been studying this population and have captured more than 800 eastern massasaugas. These snakes have been individually identified and monitored to obtain data on the population’s size, survival and reproduction. Information from this long-term data set informs conservation and recovery for this species.

Field office staff also assisted in surveying two locations in Iowa: Sweet Marsh Wildlife Management Area, managed by the Iowa Department of Natural Resources, and the Hay-Buhr Conservation Area, a property of the Bremer County Conservation Board. Although, no eastern massasaugas were found during this survey, staff learned more about each of the sites and the past survey efforts. In 2019 and 2020, Iowa Department of Natural Resources will be using the 2018 Endangered Species Act Section 6 allocation to fund massasauga surveys in the lower and upper Wapsipinicon River corridors. There has not been an in-depth survey in either of these sites in many years. The Department of Natural Resources will also be conducting modeling efforts to help identify potential habitat for the species. These efforts will be important for planning and recovery efforts for the eastern massasauga rattlesnake.

Last updated: June 8, 2020