Camp Edwards, Barnstable County

Bunnies and UXO

"Scrub oak is a very resilient plant," says John Kelly, a biologist working for the U.S. Army at Camp Edwards, a 14,433-acre National Guard training center. Fifty miles southeast of Boston, the camp represents the largest chunk of undeveloped land on upper Cape Cod. It includes an exceptionally valuable habitat for New England cottontails: 2,200 acres of scrub oak, shrubland, and forest known as the Impact Area, an artillery practice zone from World War II until 1996.

This New England cottontail will be outfitted with a radio-collar and then monitored remotely by Army biologists./J. Kelly

"A howitzer shell can land right on a scrub oak, and the plant will survive," Kelly says. "The upper stems may be obliterated, but the root system will send up new shoots." In times past, artillery rounds sparked fires throughout the Impact Area, leaving burn scars that today are covered with scrub oak, which shrugs off fire as readily as it survives being blown up. Other plants in these dense areas include huckleberry, blueberry, sweetfern, and bracken fern.

Because of its history of past disturbances, the Impact Area represents the best remaining cottontail habitat on Cape Cod. "In fact, it may support the largest remaining population of New England cottontails anywhere within the species' range," Kelly says.

"It's all about the scrub oak," he continues, describing the tough, head-high tree with wry humor: "That plant will rip the shirt off your back, knock your hat off, and steal your radio." The relatively open canopy in a shrub oak stand lets enough light reach the ground so that other wildlife food plants grow densely.

Science Plays a Role

Kelly and fellow biologist Annie Curtis are studying how New England cottontails use the habitat. Traps are set on the edges of roads that cross the Impact Area, and captured rabbits receive collars with radio-transmitters. Kelly and Curtis use receivers to monitor the bunnies' activities four times per week. The biologists keep to the roads and don't set foot inside the Impact Area where the rabbits roam: They don't want to chance stumbling into UXO, a military acronym for "unexploded ordnance," dangerous devices that can range from live hand grenades to large explosive shells.

Measuring the density of regrowing scrub oak. Rabbits and other wildlife use this habitat readily./J. Kelly

The five-year cottontail study, launched in 2011, will help determine rabbits' home ranges and the height and density of cover that they prefer. Early data suggest that the cottontails mainly use areas that have burned in the past. Individual home ranges are surprisingly large: an average of 32 acres for a female, 40 acres for a male. Because Camp Edwards is a largely unfragmented habitat, rabbits may be able to occupy larger home ranges than in areas where the land is broken up by housing and other development.

The males' larger home ranges suggest that they may be traveling to find females during the summer breeding season. The rabbits regularly cross dirt roads and powerlines, implying that these features do not represent barriers to movement.

In winter, Kelly and Curtis search other parts of Camp Edwards, looking for evidence of cottontails in the form of their fecal pellets. "The greatest concentrations of pellets are turning up in scrub-oak shrublands," Kelly says.

Fire a Tool to Renew the Habitat

The Impact Area offers great cover for wildlife, but like any habitat, it's not a steady-state environment. "In the past, this habitat was maintained by live artillery fire," Kelly explains. "But since artillery practice no longer takes place on Camp Edwards, the vegetation has been aging, with the scrub oak getting leggier and more open, and with pitch pines invading the burned areas and shading out the scrub oak and other plants."

The Army biologists teamed up with conservationists with the U.S. Fish and Wildlife Service and the Massachusetts Division of Fisheries and Wildlife worked with the Army biologists to devise a burn plan that will renew scrub oak habitat on Camp Edwards. Kelly and Curtis oversee the use of prescribed fire to burn management units both in and outside of the Impact Area; burning efforts started in the late 1990s and so far have treated around 1500 acres.

Controlled burning recreates a natural process to renew important wildlife habitat./J. Kelly

"Prescribed fire has three main purposes," Kelly notes. "It promotes safety by consuming fuel on the ground – dead branches, leaves, pine needles -- which makes it less likely that a big fire will happen in the future. It restores rare plants and wildlife whose life cycles depend on fire. And, as an exercise, it's useful in military training."

Burning stunts or kills pitch pine while rejuvenating scrub oak, restoring the habitat for New England cottontails, American woodcock, brown thrashers, Eastern towhees, prairie warblers, Northern bobwhites, box turtles, and black racers – all Species of Greatest Conservation Need in Massachusetts and other Northeastern states.

Kelly calls the Impact Area "a core habitat from which we can create sinuous fingers of rabbit-friendly scrub oak that will let cottontails move into other parts of the base and out into the larger landscape." Near Camp Edwards are other tracts of public land, including Crane Wildlife Management Area (a Massachusetts Division of Fisheries and Wildlife property) and Mashpee National Wildlife Refuge (administered by the U.S. Fish and Wildlife Service), as well as lands owned by the Mashpee Wampanoag tribe and the Town of Mashpee where conservationists are making more cottontail habitat.

"This is a great project for a beleaguered species," says Kelly. "We're able to study the cottontails' response as we create and renew their habitat. And what the Army is doing to help this threatened animal benefits dozens of other kinds of wildlife in the bargain."

How to Visit

A functioning military base, Camp Edwards is a restricted-access facility. The Massachusetts Army National Guard's Natural Resource Program hosts occasional wildlife habitat tours.

For information on efforts to create and renew young-forest habitat, and on scientific studies of New England cottontails, contact John P. Kelly, Natural Resource Manager, 508-968-5848, john.kelly19@us.army.mil.

Funding and Partners

Massachusetts Army National Guard, Massachusetts Division of Fisheries and Wildlife, U.S. Fish and Wildlife Service (New England Field Office, Southern New England – New York Bight Coastal Program, Eastern Massachusetts NWR Complex), University of Rhode Island, Wildlife Management Institute