• Start-up
  • Planning
  • Action
  • Evaluation
The eastern massasauga rattlesnake is a State Endangered Species in Wisconsin and a Federally Threatened Species. Wildlife managers and conservation biologists from the Wisconsin Department of Natural Resources (DNR) used the Adaptation Workbook and Wildlife Adaptation Menu at a workshop in April 2019 to consider statewide management strategies to maintain viable populations of this species.

Project Area

Counties in Wiscsonsin with a documented EMR occurrence
The eastern massasauga rattlesnake (EMR) depends on large wetlands and floodplain habitats along rivers and streams, where they primarily occupy open wet meadows, and adjacent upland prairies, forests, and fields. The Wisconsin DNR manages EMR on 8 extant sites across the state that contain floodplain forest, open wet meadow, poor fen, wet prairie, and sedge meadow habitats. The exact locations of these remnant populations is kept secret to protect the snakes. The accompanying map shows counties in Wisconsin with a documented occurrence of EMR.

Management Goals

Eastern massasauga rattlesnake (Photo Rori Paloski, WI DNR)

The overall goal of the Wisconsin Department of Natural Resources management is to preserve the species and maintain a viable population at each site. Managers considered specific goals for each site, which are too detailed for this summary. Management goals across the sites include maintaining open wetland habitat adjacent to upland prairie and forest, maintaining more stable water levels during overwintering periods and spring emergence, and minimizing roadkill. Specific objectives included mowing woody brush during wintertime, conducting dormant-season prescribed fires to maintain open habitats, and mowing road right-of-way areas to <6” height to deter snakes from crossing.

Climate Change Impacts

Wisconsin DNR biologists considered a range of regional climate change trends for the upper Midwest and how these trends might impact the range of extant EMR locations in the state.
Increasing winter and spring precipitation, combined with increasing heavy precipitation events, increases the risk of flooding EMR burrows
Snake fungal disease could increase under warmer conditions
Warmer winter conditions are leading to “false springs” and early EMR emergence from hibernation
Increased wildfire risk under future climate conditions and direct EMR mortality

Adaptation Actions

Project participants used the Adaptation Workbook and the draft Wildlife Adaptation Menu to develop several adaptation actions for this project, including:

Management at Extant EMR Sites
Conduct prescribed fires in uplands and wetlands in the winter rather than the spring to avoid EMR activity and take advantage of suitable burn conditions.
Conduct mark-recapture surveys at all sites to determine source populations of EMR.
Invest in efforts to eradicate non-native plants in EMR population locations and use native seed mixes that are diverse and drought tolerant.
Place downed trees around the perimeter of wetland areas for EMR basking locations.


Monitoring efforts identified by the project team included tracking the amount of acreage treated per decade through mechanical brush removal and prescribed fire at each EMR population site, EMR population size at each site, and acres of invasive species treated through various methods. The team created criteria for each monitoring variable to evaluate effectiveness and discussed how the monitoring could be implemented.

Next Steps

Project team-members are working with property managers to implement a variety of the management objectives discussed during this workshop. This page will be updated as those activities are completed. In the winter of 2019-2020, wildlife managers cleared brush, removed trees, and mowed at sites in Jackson County, Juneau County, and Buffalo County. In spring and summer 2020, DNR biologists worked with local property managers in Pepin, Jackson, and Waukesha Counties to establish weather stations and soil temperature probes to better predict springtime EMR emergence and inform prescribed burn planning.


Wildlife habitat

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