By John Davis
Safe wildlife crossings are needed on busy roads that fragment natural habitats throughout the eastern United States, to save wild and human lives and wildlife populations. The United States and Canada have opportunities now to modify roads, bridges, culverts and other human-built infrastructure to make it more permeable to wildlife movement even as we make it more durable in the face of climate chaos. The worsening storms and floods of the 21stcentury mandate infrastructure modifications anyway, and motor vehicle/wildlife collisions are expensive for people, in addition to being disastrous for the animals; so incorporating wildlife needs as we update and upgrade the built environment should be seen as fiscally prudent and ecologically necessary. Installing safe wildlife crossings can also help put Americans back to work.
Most road ecology knowledge so far is general. Conservationists have good ideas of the stretches of roads most in need of safe wildlife crossings, but have less knowledge about the exact sites where wildlife underpasses and overpasses can do the most good. There are, however, some very nearly “shovel-ready” projects. We suggest two below, after giving an example of one high-priority general area.
A general high-priority area is the Adirondack to Algonquin (A2A) wildway, linking New York’s great Adirondack Park northwestward to Ontario’s great Algonquin Park, via the Frontenac Axis and crossing the mighty Saint Lawrence River at the Thousand Islands. Canadian conservation biologists are studying the roads on their side of the border most in need of safe wildlife crossings. On both sides of the international border, road density increases near the river. On the US side, it is substantially higher outside the “Blue Line”, the boundary of Adirondack Park. Among roads fragmenting the wildway on the US side and where safe wildlife crossings are most needed are Routes 37 and 11 and 3 and Interstate 81. Studies are needed to identify where wild animals are crossing, or trying to cross, these busy roads – particularly amphibians and turtles and wide-ranging mammals like River Otter, Fisher, Marten, Bobcat, Black Bear, and Moose.
The smaller Split Rock Wildway toward the east end of the A2A wildway has at least one known specific site needing a safe wildlife crossing. Split Rock Wildway is the most secure habitat connection between the biologically rich but fragmented Champlain Valley and the Adirondack High Peaks to the west, through the botanically diverse West Champlain Hills (all contained within the UN-honored Champlain-Adirondack Biosphere Reserve). The safest way across I-87 for wildlife in Split Rock Wildway traveling from valley to mountains or vice versa is where the North Branch of the Boquet River flows beneath the interstate highway. Here, the span over the river is broad enough to allow wildlife to pass safely beneath, but modifications to the accidental wildlife crossing would help. Presently, misplaced fence and repeated all-terrain vehicle encroachment discourage wildlife movement here. Modifying the fences to direct animals toward the crossing, excluding ATVs, and replacing rip-rap with natural vegetation would make this a friendlier wildlife crossing.
Half a day’s drive to the east, but still within the Northern Appalachian/Adirondack/Acadian eco-region, is a site that ranks near the top nationally for needed safe wildlife crossings. Where Route 2 (the major east-west thoroughfare in northern New England) goes over the Bowman Divide, in Randolph and Jefferson New Hampshire, urgently needs safe underpasses and an overpass, to allow wildlife to safely cross this increasingly busy road, and reconnect wildlife populations in the Presidential Range with populations in the Kilkenny Range to the north. This is scenically spectacular area – the watershed divide between the Connecticut and the Androscoggin Rivers -- with tens of thousands of sightseers driving Route 2 every summer and autumn and admiring the highest mountains in the Northeast, so a wildlife overpass with educational signs here could be a real showpiece and source of education on the wider need for safe wildlife crossings. The late great conservationist James Meiklejohn, head of Randolph’s Conservation Commission for many years, worked for decades to convince the NH Department of Transportation to install safe wildlife crossings here. NHDOT was interested and in principle supportive, and biological studies have been done to confirm the importance of the Bowman Divide for animal movement; but money still has not been allotted to build the needed wildlife structures. Randolph’s human population is strongly supportive of land and wildlife conservation, so land-owner support may be expected here.
The Interstate Highways that fragment forests of northern New England and New York – including 87, 89, 91, 93, and 95 -- should be retrofitted with overpasses and underpasses in key wildlife movement areas that provide safe crossings for roaming animals. Sometimes this is most simply done where streams flow beneath the highways, and modifications of existing bridges may suffice. With most wildlife crossings, fencing is needed to funnel the animals to the safe places.
In short, the tragedy of road-kill – which is played out on American roads millions of times a day – can be turned into a job-creating, life-saving nation-wide effort at coexistence. The state and federal transportation agencies should work quickly but carefully with biologists and naturalists to identify places animals are trying to cross roads, and install the infrastructure that will allow safe passage. Engineers can, as they are emplacing wildlife crossings, also make our human-built infrastructure more durable for the century of climate chaos we’ve entered.
John Davis is executive director of The Rewilding Institute and editor of Rewilding Earth, as well as a board director of RESTORE: The North Woods.