Walk, bike, or drive the roads and you’ve seen the animals that didn’t make it to the other side: birds, snakes, turtles, deer, raccoons, butterflies, the occasional opossum. Sometimes there is a secondary casualty, like the great horned owl hit when scavenging on the remains of a skunk. Collectively, it’s called road kill, but of course the road didn’t kill them.
Most of us do our best to avoid animals on the road. At the very least, we pay attention and, where possible, try to increase our reaction time by slowing down: something that is easier (and safer) to do on quiet country roads than on busy highways. We’re happy to wait while the sandhill cranes walk cross the road with their flightless colts. We want that migrating monarch bouncing on a current of air to get where it’s going. We’d rather that the leaping frog in the headlights meet its end in the gullet of an egret or nice bass, ideally after having the chance to live out a reasonable lifespan and reproduce. Most of these species have a tough enough time as it is, coping with everything from natural predators to habitat loss.
Of course it’s in our own self interest, too, to avoid colliding with a deer or moose. Years ago, while working for the Forest Service in the BWCA and based out of Seagull Guard Station on the Gunflint Trail, I heard about a man who was driving his pick-up when he saw a bull moose standing in the middle of the road. He stopped and waited for it to move off. Only it didn’t. It was during the fall rut, and the moose proceeded to beat up his truck, causing an impressive amount of damage that his friends found funnier than he did.
Despite our best efforts, avoidance doesn’t always work, but any conversation about roads and wildlife has to include consideration of human behavior. This unfortunately includes intentional vehicle-wildlife collisions—that is, swerving to hit an animal—an act engaged in by a subset of the driving public that would be enlightening to see in a Venn diagram overlapped with other habits and traits. Before despairing entirely of human capacity for compassion, consider that the research here is mixed. A 2007 paper published in Human Dimensions of Wildlife reported findings from a study by a team of Canadian researchers in which more drivers (3.3%) stopped to rescue decoy (fake) reptiles placed on the road than to intentionally hit them (2.7%). Still, it makes the case for barriers or diversions like wildlife tunnels that aim to keep wildlife off the road entirely. Whatever your inclinations, you can’t hit what isn’t there.
A growing branch of science dubbed “Road Ecology” seeks answers and solutions. The book Road Ecology: Science and Solutions (Island Press), describes this specialized field of study that focuses on “two giants in uneasy embrace—road system and land,” and the implications for nature. Research around the globe has explored everything from road-related wildlife mortality, to impacts on hydrology and landscape connectivity, to erosion and chemical pollutants, to impacts of traffic sounds on bird migration and breeding.
What matters, of course, is the degree to which this research translates into conservation action, which could be said to fall broadly into one of two camps: 1) creative fixes for existing roads that are problematic for wildlife or environmentally sensitive features, and 2) design and construction standards for new roadways to minimize negative impacts.
Consider, for example, the Blanding’s turtle, a threatened species in Minnesota. Although long lived, the species doesn’t reach sexual maturity (reproductive age) until about 12 years of age. Females lay one clutch per year at most, and nest success rates are very low, largely due to predation. Road mortality places increased pressure on the state’s populations, as the turtles (adults and hatchlings) move between upland nesting sites and lowland wetland habitats on their traditional travel routes. Where populations are known to occur, redirecting the turtles to tunnels with fencing is one fix that has been employed with some success; but is not practical where these crossings occur over long stretches of roadway. Temporary “Turtle Crossing” signs have been used in known hot spots, although studies suggest their effectiveness may be limited. Reducing traffic volume during key seasons in critical habitat areas (e.g. local traffic only) is another option; one that would hinge on community support. In the “design” camp, Blanding’s turtles stand to benefit from limiting the width of roads, avoiding curb and gutter (an obstacle turtles cannot always surmount) and avoiding routing that bisects wetlands. Paradoxically, special roadway designations such as “Natural Preservation Routes” may include specifications for bike lanes that increase the width of paved shoulders, impervious surfaces, and overall road width—good for recreation but not necessarily in the best interest of wildlife or the environment.
In his role as Protected Species Coordinator for the Office of Environmental Stewardship at the Minnesota Department of Transportation (MnDOT), Chris Smith is accustomed to looking at proposed projects for how they may impact wildlife. Bats, pollinators, migratory birds, endangered and threatened species (federal and state) are all on his radar. “We’re certainly not only concerned with endangered and threatened species,” says Smith. “We try to take a broad brush approach, thinking about ecosystems as a whole. That includes swallows nesting on bridges, even the common turtles: we don’t want them getting hit on roads or being crushed in a construction project. They may be common today, but if we don’t consider them, then they may become rare in the future. We want to keep common things common and try to recover those rare things as best we can.”
All MnDOT projects undergo some level of environmental review, regardless of whether it triggers an Environmental Assessment Worksheet (EAW) or Environmental Impact Statement (EIS). “Before we ever get to the permitting point on a project, there is some DNR review and internal review through our Office of Environmental Stewardship,” says Smith. “As part of a scoping process, we identify opportunities for wildlife considerations as well as a whole other myriad of environmental issues. We’ll identify areas of environmental sensitivity (AES), which include areas with conservation value—like a rare species or high quality example of a native plant community—but also areas with something like noxious weeds that we don’t want construction equipment to spread. These are included in construction plans so that everybody involved in the actual project delivery is aware that these are ‘no-go’ zones.”
He points to two manuals in particular that commonly inform the review. “The Aquatic Organism Passage manual, or AOP, really gets to this idea of maintaining ecological connectivity, typically under our roadways,” says Smith. “It works to ensure that streams, rivers, and other wetlands have connectivity in a way that not only maintains the hydrologic piece but also allows for wildlife movement.” The other is the Best Practices for Meeting DNR General Public Waters Work Permit Manual. “That one really lays out ways to do the work to not only minimize impacts but enhance natural resource values; using native seed mixes, for example,” says Smith. “It also calls for using erosion control products that don’t carry with them some of the negative entanglement or micro-plastic issues that we see out there.” Technically, the best practices manual for public waters only applies to a specific category of waters in Minnesota where the DNR has some jurisdiction. “That said, many of the best practices are incorporated on projects where a public waters permit is not required,” notes Smith. “It’s often easiest to just follow the best practices across the board rather than having a piecemeal approach.”
Recent advancements include a new erosion control blanket that phased out plastic mesh and replaced it with natural fiber material that biodegrades, and which is constructed with flexibility that minimizes entanglement of small animals, including turtles and snakes. The Office of Environmental Stewardship was also involved in a multi-year study with the DNR and Minnesota Zoo that evaluated modifications to chain link fence specifications, showing positive benefits to turtles and other species. Smith is especially excited about the many ‘passage benches’ being installed on bridges that allow wildlife to move along these riparian corridors. “We’re having an effect across the entire state with these little actions that have an impact on a larger scale.”
We have much to gain by paying attention to management of our roadways, and much to lose.
In Managing Roadside Vegetation for Wildlife and Vehicle Safety, John Krenz of the Department of Biological Sciences at MSU, Mankato offers a list of 51 bird and mammal species reported to use roadsides in Midwestern states. This includes 27 species of birds that use roadsides for reproduction, among them bobolink, Eastern meadowlark, grasshopper sparrow, Northern pintail and shoveler, and upland sandpiper. He offers guidelines for use of prescribed burns to favor native species; careful timing of mowing that allows birds and other wildlife to complete the reproductive season; prevention of encroachment by private parties such as over-spraying of chemical treatments from adjacent fields; use of native seeds mixes; and retention of snags (standing dead trees) on the backslope of roadways to provide nesting cavities, perches and foraging sites for wildlife. “The most effective way to reduce deer-vehicle collisions,” he writes, “is for drivers to adjust their level of risk by slowing down.”
As anyone who has ever followed a new or reconstructed road project can attest, the review and permitting process is a large sieve through which many environmental degradations can still pass. Impacts can occur in the lead-up, during, or post-construction, and be due to design, methods or materials. Native vegetation can be lost to grading. Natural hydrology can be altered. Increased impervious surfaces can increase run-off and temperature in adjacent streams and ponds, impacting sensitive aquatic life. Species that rely on large blocks of contiguous forest can find their habitat fragmented by widened road corridors. Intense rain events associated with climate change have upped the ante, increasing potential for sediment to be carried to waterways in run-off. Even the “taking” of threatened and endangered species can in some cases be allowed, with mitigations meant to compensate for the loss.
Fortunately, concerted and good faith efforts by planners across multiple public agencies can minimize these, in partnership with community support.
Complex and drawn-out as road planning projects can be, the public is not out of the loop here. Granted: early in the game, if you ask a question, you might be told “It’s too soon for details.” Later, if you raise the same question, you might be told, “That will be handled by permitting.” But active community involvement in public engagement opportunities can make a meaningful difference, especially on the front end of projects so that planners and local leaders know that many people care, and during the permitting process so that oversight agencies from the DNR to the local watershed district know that people are still paying attention. There is typically some room to move within the necessary guardrails of engineering and safety, allowing communities to “connect the dots” between the conservation values of their comprehensive plans and any given project. Whether it’s a MnDOT project, a county project, or local road project, citizens can encourage best management practices, and will often find a receptive ear.
People who live in an area know it intimately. They can relate their first-hand observations of wildlife through the seasons and over the years. They know where the turtles cross, when the red-shouldered hawk nests, how the herons and otters feed along the cattail marsh, the ephemeral pools in the ditches where frogs sing in the spring.
With a little care and patience, these things don’t have to be lost in our busy world, as the price we pay for our comings and goings. There can still be life on the road.
Resources:
Best Practice Manual for Meeting DNR General Public Waters Work Permit GP, Chapter 1, Species Protection
See Chapter 8: Best Management Practice No. 8: Managing Roadside Vegetation for Wildlife and Vehicle Safety (in) Best Practices Handbook for Roadside Vegetation Management, Ed. Ann Johnson, Local Road Research Board published by the Minnesota Department of Transportation.
Image Notes: All photos by Laurie Allmann. Special thanks to David Spohn for designing the great “Watch for Life on the Road” sign for this story. AGATE is looking into making it available for wider use, subject to local and state road policies. Stay posted!
