Big Rock Valley features about 550 acres of wetlands, which includes a 10-acre lake, ponds, streams,  calcareous fens and a lakeside fen, and marshes. The area’s many natural springs provide abundant water flow to these wetland areas, ensuring an influx of fresh nutrients and a healthy ecosystem.

Eastern massasauga rattlesnake

Big Rock Valley’s wetlands are home to some 30 varieties of amphibian and reptile species, including the eastern massasauga rattlesnake, which won federal listing as a threatened species in fall 2016.

Massasaugas play an important role in biodiversity, says Mike McCuistion, the foundation’s vice president of physical resources.“Massasaugas serve as both predator and prey, which makes them a critical component in the environment.”

Because the massasauga’s primary diet consists of mice and voles, they help control rodent populations. The snakes, in turn, provide food for hawks, owls and other predators. “For biodiversity to thrive, you want as many native species as practical,” McCuistion explains. “If one plant or animal begins to decline, it can disrupt the balance of an entire ecosystem.”

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Eastern Massasauga


Researcher Takeaways


Surprising salamander species

Jim Ball, a private researcher and herpetologist, began  studying salamanders at Big Rock Valley in 2003. Among his discoveries has been a hybrid salamander with genes from three different species that previously had been sighted only on an island in Lake Erie.

“This has made the scientific community rethink all of our old ideas on what kinds of salamanders are found in southern Michigan,” Ball says. Another find: a large neotenic tiger salamander, which remains in the larval stage but continues to grow. “Because the foundation’s property has been managed so carefully, it’s an ideal place to look at biology,” Ball says. “Things continue to thrive here that have declined elsewhere in the state.”

Fish population

The property’s ponds and lake contain numerous fish species, including bass, bluegills, crappie, perch, pike, gar, as well a variety of minnows and smaller fish. Unfortunately, carp — a nonnative, invasive species — migrated to Sharkey Lake from a downstream location. Management efforts have been implemented for population control to reduce the threat of major negative impact on native species.

Why we should warm up to these cold-blooded critters

“The property is a gem...”

Billie Harrison, supervisor of the Aquatic & Reptile Center at the Milwaukee County Zoo, has been working on the massasauga study at BRV since the EMR SSP’s inception in 2009. “The property is a gem,” she says. “It has a spectacular variety of wildlife and has been so well managed, I really look forward to coming back every year.”