Sustain Our Nation's Forests and Grasslands

Habitat improvement project will have many benefits for eastern massasauga rattlesnakes

Eastern massasauga rattlesnake overwintering habitat. Forest Service photo.

MICHIGANHuron-Manistee National Forests have taken the first step to implement a landscape level plan to manage for the conservation needs of federally threatened eastern massasauga rattlesnake (Sistrurus catenatus) within historic pine barren habitat.

In winter, massasauga hibernate singly or in groups below the frost line with their bodies submerged underwater, in crayfish or small mammal burrows in wetlands and along riparian floodplains. The presence of water that does not freeze is believed to be essential to hibernaculum suitability.  Massasaugas emerge in April, as groundwater levels rise and soil temperatures approach air temperatures. They then spend several weeks basking near the hibernaculum before moving to drier upland habitats in summer.

Eastern massasauga rattlesnakes need less than 50% forested canopy closure to meet thermal demands.  The crayfish burrows massasauga use are generally not found in heavily shaded habitats, thus limiting the number of hibernation sites.

In 2017, a Great Lakes Restoration Initiative Project was implemented on the Cadillac-Manistee Ranger District to improve massasauga hibernacula habitat. This project cut mature tag alder on 15 acres to improve the area for post-emergent basking by opening the forest canopy to sunlight. Brush piles were also created to provide hiding cover for massasaugas.

Future management includes timber and other mechanical treatments, prescribed fire, planting of native grasses and wildflowers, and suppression of non-native invasive plants to create a more open condition in pine barren habitat. These treatments will improve habitat suitability by reducing overstory canopy cover, thus increasing abundance of warm season grasses and woody debris used for cover. This management will increase prey availability, as well as improved basking and hunting sites, particularly for gravid females.

Eastern massasauga rattlesnake basking in hibernacula habitat. Forest Service photo