“I’ve got some pellets here.”
“Here’s a run!”
The run was a path in the snow made by rabbits – specifically, rare and imperiled New England cottontails. The pellets? New Hampshire Fish and Game biologist Heidi Holman was referring to small, rounded, brownish rabbit droppings. Those telltale signs of habitation brought smiles to the faces of Holman, U.S. Fish and Wildlife Service endangered species biologist Anthony Tur, and Jenna Bourne, an employee of Stonyfield Yogurt, in Londonderry, New Hampshire, on whose land the group was walking on a sunny late-February day.
The searchers tramped through a foot of snow. They picked their way past clumps of six- and eight-foot-tall alder, aspen, birch, and maple while judiciously avoiding concertina tangles of multiflora rose. This was thicket habitat – a blend of shrubs and young trees that provides the dense cover New England cottontails need. Three years earlier, a timber harvest had spurred the growth of that vegetation, and the local cottontails responded by moving in. Wilderness it wasn’t: the 11-acre patch wrapped around three sides of Stonyfield’s Yogurt Works, a low gray building; planes roared overhead, headed for landings at nearby Manchester Airport; and trucks beeped while backing up at other light-industry plants nearby.
These days, biologists are happy to confirm the presence of New England cottontails anywhere they can. Since the 1960s, the species has lost an estimated 86 percent of its habitat, and its range has contracted to five subpopulations separated from one another by miles of mature forests, highways, shopping malls, and housing developments. Its numbers have fallen so low that this once-abundant regional rabbit is now being considered for endangered or threatened status under the federal Endangered Species Act.
In New Hampshire (where it’s been on the state endangered list since 2008), as few as three dozen New England cottontails may remain. Next door in Vermont, New England cottontails have vanished – conservationists consider them extirpated, though they once ranged across the state’s southern tier and north through the Champlain and Connecticut River valleys. Maine has 250 to 400 rabbits (state endangered since 2007), all in the coastal southwest. A few New England cottontails may be left in Rhode Island – or perhaps none. The Massachusetts population numbers in the hundreds, mainly on Upper Cape Cod and in the Berkshires. Connecticut may have a couple thousand New England cottontails in its eastern and northwestern sections, and a similar number may live in New York state, east of the Hudson River and in the Taconics.
But wait – aren’t cottontails seen with fair frequency in southern New England? Yes, but the rabbits hopping across golf courses and nibbling suburban lawns are not New England’s own. They’re eastern cottontails, as alien to the region as the autumn olive, Asian honeysuckle, and multiflora rose that have quietly taken over much of the shrubland that remains. In times past, only New England cottontails existed in New England. Folks called them coneys, brush rabbits, and woods rabbits. They lived on abandoned farms that were reverting to forest, and in areas where wildfires, windstorms, beaver dams, springtime flooding and ice scouring, and heavy logging had temporarily toppled, killed, or otherwise removed older trees so that young trees and shrubs could come crowding back in.
All of those factors, except storms, have been blunted. Yesteryear’s farms are now mature woods stitched with stone walls. Dams by the hundreds limit ice scouring and floods. We humans have suppressed wildfires and beaver activities to protect lives and property and have covered much of the land with development. Heavy logging is almost nonexistent in southern New England, much of which is cloaked with closed-canopy middle-aged and older forest – a type of habitat that, although natural and needed by some kinds of wildlife, does not offer enough low-growing vegetation for New England cottontails or around 60 other young-forest-dependent creatures, including woodcock, brown thrashers, towhees, chestnut-sided and blue-winged warblers, and box and wood turtles. The populations of all these animals – identified by the states as “species of greatest conservation need” – have been falling over the past 50 years as the amount of thicket and young-forest acreage has steadily dwindled.
Two Different Rabbits
For the New England cottontail, there’s an extra odd twist: During the first half of the twentieth century, state wildlife agencies and private hunting clubs released thousands of eastern cottontails (most of them from Kansas, Missouri, and Texas) to boost hunting opportunities. Eastern cottontails don’t pop down holes as readily as New England cottontails do, which let hunters enjoy longer chases with their rabbit hounds and upped their chances of bagging a bunny. Those imported eastern cottontails caught on, and today they greatly outnumber the native rabbits across most of southern New England.
The New England cottontail (Sylvilagus transitionalis) and the eastern cottontail (S. floridanus) do not interbreed, or if they do, offspring apparently don’t survive. An adult eastern cottontail is a bit larger than a New England, weighing three pounds versus about 2.2 pounds. Otherwise they look similar, with a mottled brown-and-black pelt and a white powder-puff tail. Most New England cottontails have a small black spot on the forehead, whereas about half of all easterns have a white spot in the same place. The New England’s ears are slightly shorter than the eastern’s and have a thin line of black fur along the outer edge. Skull shape differs between the species as well.
Most of what we know about cottontails in New England comes from research conducted by John Litvaitis, a professor of wildlife at the University of New Hampshire. Beginning in the 1990s, Litvaitis and his graduate students went looking for rabbits and their habitat all over southern New England. Their field work galvanized conservationists and helped put the New England cottontail on the shortlist for potential federal endangered status. The researchers also developed a protocol for extracting DNA from rabbit pellets, revealing whether the droppings come from New England or eastern cottontails, which lets biologists chart where the former remain. (For example, ongoing pellet studies have revealed that all of the cottontails around the Stonyfield Yogurt plant are New Englands.)
The researchers also studied how the two kinds of cottontails interact. After putting both types of rabbits in a thicket enclosed by wire fencing, they concluded that the larger eastern cottontail does not dominate or displace the smaller New England cottontail from its habitat. “The only detectable difference between them,” Litvaitis wrote in a 2002 article in New Hampshire Wildlife Journal, “was that eastern cottontails were often observed in areas with little understory cover.”
The scientists built another pen and installed feeders with electronic sensors, which allowed them to monitor when a rabbit was present. They found that eastern cottontails traveled farther from protective cover to get food. “Our farthest feeder was about 60 feet from cover,” wrote Litvaitis, “a long distance for a rabbit trying to avoid a hungry fox or owl.” Although eastern cottontails would chow down at those feeders, “New England cottontails were very reluctant to visit [them] unless they started to lose weight and were clearly very hungry.”
When the researchers sent a life-sized owl decoy gliding along a wire suspended over caged rabbits, eastern cottontails spotted the approaching decoy when it was 70 feet away. New England cottontails didn’t see the owl until it was only 30 feet away.
Why, the scientists wondered, could an eastern cottontail spy a predator so much farther off than could its Yankee cousin? The answer turned out to be fairly simple: the eyes of Eastern cottontails are 50 percent larger than those of New England cottontails, giving them better long-range vision. Likely, this more-acute vision developed because the eastern cottontail evolved in open plains habitats, where it needed to detect danger at a distance. In contrast, the New England cottontail evolved in shrublands, such as mountain laurel and scrub oak thickets, and in young forests created by fires, floods, hurricanes, and beaver work; in such dense settings, a woods rabbit didn’t need to spot far-off predators.
Today, their long-range vision lets eastern cottontails use the small patches of thicket habitat that remain in southern New England: an acre of invasive shrubs behind a strip mall, a briar patch bordering a gravel pit, a hedge in somebody’s backyard. From such tatters of cover, eastern cottontails creep out to feed on grasses, clover, plantain, and other low herbaceous plants in summer, and on woody vegetation in late fall, winter, and early spring – and are better able to dash back to cover if a predator threatens. “Because staying close to cover is probably the best strategy in forest habitats,” Litvaitis concluded, “New England cottontails suffer disproportionately when cover shrinks.”
In the wild, the fate of almost every rabbit is to be killed and eaten by a predator. The researchers identified red foxes and coyotes as the most common causes of death among 75 radio-collared free-ranging New England cottontails that they monitored in southern New Hampshire. Cottontails are also preyed on by fishers, mink, weasels, hawks, owls, large snakes, bobcats, domestic cats and dogs, and humans. Skunks and raccoons raid the natal nests – made from grasses and from fur that the mother-to-be plucks from her own coat. Another Litvaitis study showed that the variety and number of predators goes up in fragmented, human-modified landscapes such as those of southern New England.
Based on years of study, Litvaitis suggested that for New England cottontails to occupy a given site indefinitely, they need a minimum of 20 interconnected acres of good-quality thicket. Winter is a tough time for rabbits: Instead of feeding on (and staying hidden in) the abundant greenery of summer, they skulk in thick shrubs or underground burrows by day, then venture out at night to nibble on the bark, twigs, and buds of woody plants, food that is much less nourishing than summer fare. In winter, the protective cover is at its thinnest, and if snow blankets the ground for long periods, the rabbits stand out sharply against the white background. (Unlike the larger snowshoe hare, another New England native, neither the New England cottontail nor the eastern cottontail takes on a protective white coat in winter.) Litvaitis found that in habitat patches 12 acres and larger, about 7 out of 10 New England cottontails will make it through winter. But once a patch gets smaller than about six acres, winter mortality can soar to 66 percent. And if the habitat continues to shrink, its resident population will wink out.
Helping Nature Along
The recently improved habitat patch at Stonyfield Yogurt covers 11 acres, which implied that the “dozen” rabbits thought to inhabit the tract might have dwindled to eight by that February day when Tur, Holman, and their colleagues went looking for cottontail sign. Those theoretical eight bunnies would likely repopulate the patch during the year to come. Offsetting the fact that cottontails are food to so many predators is their great reproductive capacity: A female can have three to four litters per year, with an average of three to four young per litter. Cottontails are born blind, but they develop quickly. A rabbit’s conception through its birth, weaning, and independence takes only 60 days. Females born early in the year may produce a litter of their own that same summer.
The previous autumn, Holman had live-trapped and removed two New England cottontails from the Stonyfield patch. The improved habitat had helped boost bunny numbers during the breeding season, so the biologists felt they could safely take a couple of individual rabbits without harming the local population. The two rabbits went to Roger Williams Park Zoo in Providence, Rhode Island, to become part of a captive breeding program that, coupled with habitat-creation efforts gearing up all over the species’ range, aims to save Sylvilagus transitionalis from extinction.
Since 2010, captive-breeding specialists at the zoo have been perfecting housing, feeding, and breeding protocols. Their goal is to produce the maximum number of healthy brush rabbits that can go back into the wild, both to boost the numbers and genetic diversity of existing populations and to start new populations in places where conservationists are making habitat.
As of March 2013, 17 female and 10 male New England cottontails were housed at the zoo, with the year’s breeding just getting underway. So far, 15 captive-bred rabbits have been released on brush-covered Patience Island, a 210-acre uninhabited island in Narragansett Bay. This year biologists hope to confirm natural reproduction there; if the island population thrives, it could become a source for restocking other areas. Conservationists have also built two hardening pens, at Ninigret National Wildlife Refuge in Rhode Island and Great Bay National Wildlife Refuge in New Hampshire. Young captive-bred rabbits will spend a month in those one-acre, predator-proof enclosures learning how to hide in cover and feed on native vegetation; then it’s off to the real world, red in tooth and claw.
“We’d like to have a hundred or more animals come out of the zoo in 2013,” Tur said. “The effectiveness of captive breeding will be measured by whether or not captive-bred individuals can go back into the wild, reproduce, and bear young.”
Captive breeding will likely be a key aspect of restoring the New England cottontail. But if there isn’t enough habitat out there, the overall effort will fail.
Habitat is the Key
Making rabbit habitat is the goal of a partnership formed in 2007 between the five states that still have New England cottontails, the U.S. Fish and Wildlife Service, and the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS). A Conservation Strategy for the New England Cottontail, written by Tur and Steven Fuller, a scientist who coordinates the rangewide New England Cottontail Initiative, came out in November 2012. (It can be downloaded here.) Developed with input from state wildlife biologists, the document maps 47 focus areas where, between 2012 and 2030, conservationists plan to create more than 50,000 acres of habitat to support 28,100 New England cottontails – enough, scientists believe, to save the species.
How to make that habitat? Potential management techniques include even-aged timber harvests (both clearcuts and shelterwood cuts); noncommercial timber harvesting (cutting down trees that are not large enough to provide a financial return); mowing or mulching old, straggling shrubs; and conducting controlled burns. All of those methods mimic the kinds of catastrophic natural events that once operated freely to make early -successional habitat. All remove the forest or shrub canopy and let sunlight reach the ground, which spurs the growth of low, thick vegetation. Such management practices must be ongoing, because shrubland and young forest generally remain good rabbit habitat for only about 20 years. After that, their leafy crowns knit back together and exclude sunlight, and groundcover once again gets sparse.
A major component in a New England cottontail comeback is the NRCS’s Wildlife Habitat Incentive Program (WHIP). WHIP funding has helped more than 20 private landowners make over 350 acres of potential cottontail habitat in New Hampshire, and this year another 10 landowners will begin projects on an additional 150 to 200 acres. WHIP is also enabling private-land projects in the other New England cottontail states, particularly in areas next to habitats, such as scrub wetlands, that support existing cottontail populations. Recently the NRCS began a nationwide Working Lands for Wildlife (WLFW) initiative that features the New England cottontail as one of seven wild animals for which the agency will help farmers and forest landowners make critically important habitat. In 2012, WLFW issued contracts pledging to pay 44 landowners $1.5 million to make New England cottontail habitat on more than 1,300 acres. States, other federal agencies, and organizations such as the National Fish and Wildlife Foundation have committed several million dollars to New England cottontail recovery as well.
Another New Hampshire project illustrates what can be done on public land – in this case, the 428-acre Bellamy River Wildlife Management Area near Dover. In 2011, loggers harvested low quality white pines and hardwoods with a 30-acre clearcut. The following spring, saplings began springing up from the root systems and stumps of the logged-off hardwoods. Over the next several growing seasons the clearcut should metamorphose into a jungle of dense trees and shrubs. The clearcut is next to cover where New England cottontails live, so the rabbits ought to jump right in. Conservationists have also been planting native shrubs such as dogwood, hazelnut, and arrowwood. “We estimate there are about 200 acres of potential New England cottontail habitat on the wildlife management area,” said Jim Oehler, a biologist with New Hampshire Fish and Game. “Over time, we hope to keep 75 percent of that acreage in suitably dense bunny habitat.”
Other conservation efforts in the Granite State include agreements with utility companies to lessen the frequency with which they mow power-line and gas-line corridors; the companies will simply remove trees as they get too big. “The idea is to continuously maintain thicket cover,” Holman said. Biologists hope New England cottontails will use the brushy corridors to disperse from one population to another, occupying habitat patches as they are renewed or created, and maintaining genetic flow within the species.
In Connecticut, biologists and foresters with the state’s Department of Energy and Environmental Protection have created sizable habitat patches on four state properties and plan work on six more state-owned tracts. Clustered around those sites are projects on private lands, like the one on aptly named Cottontail Farm near the town of Scotland. There, landowner Tom McAvoy is improving shrub habitat in five fields by rooting out older invasive shrubs, such as autumn olive, and replanting with native shrubs that offer better food and cover. A 10-acre timber harvest took place in February 2013; soon, regrowing oaks, maples, and hickories, along with a dense blueberry understory, will add to the habitat mix. “I look at this as a legacy project, one that my sons will be part of in the future,” said McAvoy.
In addition to WHIP funding, McAvoy received help through the U.S. Fish and Wildlife Service’s Partners for Fish and Wildlife program. Ted Kendziora, a biologist working out of the Service’s New England field office, supplied planning, technical advice, and funding, then supervised the private contractors who did the actual habitat-enhancement work.
Kendziora is helping landowners make habitat in every state across the New England cottontail’s range. One area with a good population of New England cottontails is Upper Cape Cod, where more than 400 acres of fresh rabbit habitat have been created by the Town of Mashpee, Orenda Wildlife Land Trust, the Wampanoag Mashpee Native American Tribe, and the Trustees of Reservations, along with the state of Massachusetts and the U.S. Fish and Wildlife Service’s Eastern Massachusetts Refuge Complex. Many of the tracts abut or lie close to each other. And only a mile down the road is the Massachusetts Military Reserve at Camp Edwards, where wildlife biologists have conducted controlled burns on more than 1,500 acres of coastal scrub since the 1990s and where a robust New England cottontail population remains. The use of fire in this sandy coastal environment removes dead vegetation and makes it less likely that large, out-of-control wildfires will flare up in the future. Prescribed burning also renews scrub oak, a lowgrowing, fire-evolved oak that’s more of a shrub than a tree and, when young and dense, offers great rabbit habitat.
So while the situation looks bleak in some parts of its range, conservationists are optimistic that they can reverse the population drop the New England cottontail has taken over the last half-century. According to the Conservation Strategy for the New England Cottontail, around 145,000 acres of public land are highly suitable for turning into woods-rabbit habitat. Focusing management on public tracts would make for substantial cost savings compared to creating habitat on private parcels and would reduce the number of management actions needed, along with their accompanying planning and oversight. It would also increase the opportunity to use cost-effective controlled burning as a management tool, plus generate income – and jobs – from timber products.
To make the habitat that the New England cottontail needs, conservationists will have to change the public’s perception of management activities such as burning brush thickets or clearcutting generous-sized forest tracts – not an easy task in heavily wooded southern New England, where many people shudder at the idea of cutting down even a single tree and where state and local regulations often severely limit the extent and siting of logging jobs.
As an endangered species biologist, Anthony Tur works with many animals, from the American burying beetle to Blanding’s turtle to the mountaintop-dwelling Bicknell’s thrush. “The New England cottontail is an important part of the wildlife legacy and biodiversity of our region,” he said. “All species have an inherent value, and all of them have a place on the landscape. If humans are the reason for an animal being in trouble – and clearly we’re part of the problem the New England cottontail is facing today – then we have a moral responsibility to work hard to keep that animal around.
“In particular, the New England cottontail is a good barometer of the health of a certain kind of habitat: dense thicket vegetation. When we make habitat for New England cottontails, we help out many other kinds of wildlife. I think we’ll be successful in this effort. Cottontails are prolific animals. If we supply the habitat, the rabbits will do the rest.”