Thoughts on Roads and Wildlife
With the stones we cast at them, geniuses build new roads with them. –Paul Eldridge
Thanks to the Interstate highway system, it is now possible to travel across the country from coast to coast without seeing anything. –Charles Kuralt
Like it or not, roads have become the arteries of our social and economic lives. Roads are necessary to transport goods and services to the marketplace, move people to and from their places of work, shopping, and social engagements, and serve as vital links to public health, safety and welfare. Roads in the U.S. cover about 1% of the land area, an area equivalent to the state of South Carolina. It is estimated, however, that 20% of U.S. land area is directly affected ecologically by the road system. But in our quest to build roads to serve our burgeoning needs, biodiversity — that is the total diversity and variability of living things and the systems of which they are apart of — seems to have been left by the roadside. Like them or not, roads have a far reaching impact on biodiversity, both in terms of new construction and ongoing operations.
Typically when we think about roads and wildlife, the first thing that comes to mind is direct impacts to wildlife – road kill. It is estimated that in the U.S. approximately 1 million mammals are killed on roadways annually. If we consider insects, amphibians, birds and a host of other taxa, we are most likely looking at billions of species each year. In the United Kingdom, it is estimated that millions of birds and 20-40% of UK’s breeding population of amphibians are believed to die each year on roads. Even the mere presence of a road can impact wildlife species. Dutch research for example, showed that out of 12 bird species examined, 7 exhibited reduced densities near roads than in similar habitats away from roads. Roads are also responsible for changes in plant species composition, plant performance and soil nutrient levels along their right-of-ways.
While direct impacts are important to consider, it is the indirect impact that may have the biggest effect on terrestrial, aquatic and avian species. Fragmentation of habitat (link to our past Leaf Litter issue on fragmentation), water runoff pollution, air pollution, noise and artificial light pollution, along with the effects of spillages, litter and roadside management practices all can erode the quality of biodiversity and ecological integrity of the landscape.
While almost any form of road development will have some negative effect on the environment, there are many promising initiatives taking place throughout the world to reverse this trend. Many European countries are taking bold steps to initiate biodiversity action plans that address methods to reduce and mitigate road impacts on wildlife. These initiatives range from broad policy goals to preserve habitat connectivity (see Guiding Principles for Conducting Biodiversity Assessments for Road Projects (UK) provide link) by promoting mass transportation projects and better land use planning, to specific mitigation techniques to allow wildlife movement across roads. Many U.S. transportation agencies are also beginning to incorporate both wildlife avoidance and mitigation strategies in road design.
In this issue of Leaf Litter, we highlight measures to protect, restore and mitigate wildlife habitat in relation to roads. We also interviewed Bethanie Walder, Executive Director of the Widllands CPR. Wildlands CPR is becoming one of the leading authorities and sources of information on the ecological effects of roads and off-road vehicles. Bethanie talks about some of the strategies being used to mitigate and restore ecosystems impacted by roads. Our Leaf Litter Survey on roads and their impacts to wildlife brought in some interesting comments, provocative thoughts and probing questions. Be sure to check it out. Finally, we have packed this issue of Leaf Litter with plenty of resources, information and links for you to take action. Remember:
He who walks in the middle of the road gets hit from both sides. -George Schultz
Keith Bowers, Principal, Biohabitats, Inc.
Leaf Litter Talks with Bethanie Walder, Executive Director, Wildlands CPR
There are few people around the country who are as immersed in the field of road removal as Bethanie Walder. As an undergrad at Duke University in the late 80’s, Bethanie was an avid camper in the forests of North Carolina. Upon returning to a favorite hiking spot one year to discover that numerous trails had been turned into roads, Bethanie became quite disillusioned about the role of the U.S. Forest Service and embarked on a personal research mission to find out more.
Assuming that the Forest Service simply protected our forests, she was surprised to learn about timber programs and road construction programs that seemed contrary to the goal of protecting forests. Eager to learn more about forestry and forestry issues, Bethanie enrolled in the Environmental Studies graduate program at the University of Montana. As she was completing her thesis on natural and human disturbance effects on forest ecosystems, Bethanie landed a job as co-director of Wildlands CPR – which, at that time, was called ROAD-RIP. The organization was founded in 1994 as a clearinghouse for research and information on road and off-road vehicle impacts to the environment. Today, Wildlands CPR maintains a 10,000 citation database on the ecological effects of roads and off-road vehicles and offers a multitude of guide books. Wildlands CPR has trained over 1,000 people around the country in these techniques and works closely with numerous land management agencies to advance more restorative and beneficial care of the land.
Leaf Litter recently had the opportunity to speak with Bethanie – just before she jaunted off to a rafting trip on the Lower Salmon River in Idaho – to get her thoughts on the subject of roads and their impact on the environment. Here’s some of what she had to say…
First let’s touch briefly on the differences between mitigation and restoration as it applies here.
Mitigation is, by definition, reducing or lessening an impact – not getting rid of it. Where as restoration – in my definition – is removing an impact so that you are restoring a habitat to a functioning capacity. There is a real link between restoration and mitigation and at some level restoration is just a stronger form of mitigation.
For example, if you want to reduce the impact of a highway on wildlife, there are a number of ways to do that. You can fence a highway to minimize road kill – but then you are imposing a wildlife barrier. You may have reduced road kill but you’ve increased habitat fragmentation. You can fence the road in combination with a wildlife overpass or underpass or some other type of crossing structure. This reduces road kill and allows for some level of connectivity, but even with these structures in place you are not restoring 100% connectivity to an area. You are restoring connectivity in a set number of places. That connectivity is critical, but you are only mitigating the habitat fragmentation you’re not restoring the area.
How do roads impact wildlife habitat?
The major impacts are habitat fragmentation, animal mortality (road kill), sedimentation that pollutes our waters, and the spread of non-native and invasive species – which is a significant problem along road right-of-ways.
From an aquatic perspective, roads completely change how water interacts with land. A perfect example of this is Route 41, which runs from Miami to Tampa, through the Florida Everglades. Route 41 functionally acts like a dam in the Everglades. You have all of this sheet (water) flow across the Everglades and it just hits the road and can’t get across. As part of an Everglades restoration plan, there is a proposal to elevate an 11- mile section of Route 41 up above the Everglades. Should this come to fruition, it would be such an amazing restoration opportunity that would result in 11 miles of virtually complete connectivity.
What types of crossings are being used to mitigate the impacts of roads on wildlife?
There are both terrestrial and aquatic crossing structures.
Underpasses – Large concrete structures or metal pipes or arches are used to create a tunnel under the road. In addition, regular culverts that are used to pass water under a road can be retrofitted with little ledges along the length of the culvert, above the water line, so small mammals can cross on the ledge.
Overpasses – or eco-ducts or wildlife bridges are constructed with dirt and vegetation to create contiguous habitat across the road. This type of bridge has been in use in Europe for many years and has been proven to be incredibly effective. They’ve also been used in BanffNational Park (Canada). Researchers have found however that it takes time – sometimes several years – for wildlife to become acclimated to using these bridges.
Extended bridges – When you build a bridge across a river, for example, instead of finishing the bridge just at the water’s edge, you keep that bridge raised for another 5 yards to 100 yards or more so that there is a natural land embankment for wildlife to travel under that road. This kind of crossing is really fantastic because it is so natural and you are maintaining complete connectivity across that part of the wildlife habitat.
A good example of this is here in Montana on Highway 93 which is being re-constructed from Missoula to Polson. The highway is increasing from a two-lane to a three/four-lane highway in most areas. There will be 42 wildlife crossing structures – a combination of overpasses and underpasses bridges – installed along this 45-mile stretch.
Retrofitting or Replacing Culverts – The U.S. Forest Service and many state agencies are upgrading culverts to install larger and better engineered culverts that are retrofitted for fish passage. Most older culverts were designed and constructed solely to pass water and not fish. When fish are trying to get upstream to their spawning grounds if the existing culvert isn’t designed at the original stream bank level it can create a waterfall at the edge of the culvert. For certain fish, these waterfalls are too significant of a barrier for them to pass through. Also, because culverts confine a whole stream into what is essentially a small tube, it dramatically increases the velocity of the water and that too can create a problem for the fish – even if the culvert is level with the stream bank bottom.
One technique being used is essentially squashing culverts – leaving the top like a regular culvert yet flattening out the bottom to create more of a natural gradient like a stream bottom. In some cases they are using half culverts to create less expensive bridges. In these examples, the natural stream bottom is maintained to pass macroinvertabrates and fish – with no interruption whatsoever.
A good example of a successful culvert retrofit is one completed by the Clearwater National Forest in Idaho about two years ago. A stream in which they had not seen steelhead trout for about 50 years, had signs of the return of this species just one year after the retrofit.
It is very important to point out however, that there is not one sure fit solution for all circumstances. In some places culverts have actually prevented invasion of native fisheries from non-native fish. Culverts can block passage for both native fish and non-native fish. There are some places where the land manager may determine that the risk to the native fishery is greater if you replace the culvert than if you leave it there. So, as you can see, connectivity is not always a straight forward thing.
How does wildlife know to use these crossings?
They don’t always use them. That’s why fencing is used to guide wildlife to the crossing structures. Scientists have found that animals learn where these crossing structures are and they use them more frequently. Over time, scientists and ecologists have made many improvements to wildlife fencing. “Escape ramps” have been created on the road side of the fence – for example a five-foot hill of dirt – which a deer could use to walk up and jump over the fence to the other side so that they can get out of the right-of-way. These seem to work better than “one-way” gates that an animal can push through in one direction but not in the other.
It’s also important to note that the dimensions of wildlife crossings influence how successful they are. Different wildlife species prefer different types of structures. For example, if you are trying to get deer or elk across a road, you’ll need a different sized structure than if you are trying to get smaller mammals across a road. Smaller, prey species prefer a really confined space because they don’t want to be out in the open. Where as ungulates – like deer and elk – prefer a really big open space because they want to be able to see around them. So it may be necessary to use a wide variety of crossing structures along a stretch of road.
While crossing structures seem to work for nearly every type of animal, it can be expensive to retrofit old roads. For example, thousands of Common Toads in England have been killed by cars while trying to cross roads. During breeding season in late March or early April, Common Toads have a strong urge to return to their birth pond and are killed while crossing the road. Environmental organizations, like Froglife, have formed “toad patrols” – groups of volunteers who go out during breeding season and literally collect all the frogs in buckets and carry them across the road. Even in rural areas with very little road traffic, the mortality rate can be nearly 100%. For this reason they also advocate for amphibian tunnels to allow frogs to cross the roads on their own.
What can you tell us about wildlife detection systems?
This is an emerging field in wildlife mitigation – and it does not require the use of fencing, which may in fact contribute to habitat fragmentation. However wildlife detection systems may also be combined with fencing or other mitigation measures such as wildlife underpasses and overpasses. There are a number of different types of technologies being tested to determine which ones will be most effective in which situations.
Animal detection systems inform drivers that animals are present in the immediate vicinity, instead of relying on “deer crossing” signs that are posted all the time, regardless of the immediate presence of animals. Some systems being tested use a “break the beam” type technology that trigger lights to blink if an animal breaks an infrared, laser or microwave radio signal beam. There is also a system that relies on radio collared elk on the Olympic peninsula in the state of Washington. Since this resident herd of elk travels together, the dominant animals have been radio collared to activate blinking road signs when they are in the vicinity of the road. The Western Transportation Institute at Montana State University is conducting some of the research on this topic.
In our survey we asked readers about their use of mass transit as a means to mitigate transportation hazards to wildlife. But mass transit is clearly not a practical solution, or even available, for everyone. What are your thoughts on mass transit?
If you’re living in an urban area good mass transportation options are a critical step, but major urban areas also tend to contain little viable wildlife habitat. But let’s look at mass transit from another perspective. There’s been a lot of discussion about electric cars, hybrid vehicles, hydrogen powered cars, etc. – but that individual form of transportation only necessitates more roads. It would be great if we could reduce air pollution by reducing the amount of gas we use, but it won’t reduce the congestion and road construction if our society continues to be based on individual modes of transportation.
There are a couple of really good books on this topic. One book, written by one of the founders of Wildlands CPR, Katie Alvord, is called “Divorce Your Car: Ending the Love Affair with the Automobile” — it deals with these larger issues of the effects of an individual car culture on the environment as a whole. Another great book on this subject is by James Howard Kunstler called “The Geography of Nowhere: The Rise And Decline of America’s Man-Made Landscape” and it’s about how our society at the turn of the century shifted very deliberately from a mass transit based society to an individual car culture. Who was behind that change? The auto industry of course. This shift greatly reduced our country’s investment in mass transit, while concurrently increasing our investment in road and highway construction.
One brilliant solution for people who live in cities is car sharing, which originated in Switzerland in the late 80’s. There are more than a dozen such programs in the U.S. where individuals pay a small fee to have access to a fleet of cars that are shared by a large number of people. It’s a great way to save money on car ownership and do something good for the environment at the same time.
Which states are most pro-active in addressing road removal and mitigating road impacts on wildlife?
Two that stand out are Montana and Florida. Within the last couple of years, Montana has really taken a lead in this field. Case in point — the example I gave earlier with Highway 93 which is being done through a memorandum of agreement between Montana Department of Transportation (MDT), the Salish Kootenai Indian Tribe, and the Federal Highways Administration. And in Florida, the DOT built culverts under I-75 for panther crossings.
We are starting to see more and more states getting interested in wildlife crossings – though in some instances they may be more concerned about road kill than habitat connectivity. Highway departments tend to be more interested in safety, human mortality and costs. Road kill is very expensive in terms of human lives and insurance costs. So there are different motivations in different places for addressing the issue of wildlife crossings.
What is being done in other countries to mitigate the effects of large roads or highways on wildlife?
This field it is in its infancy in the U.S., but it is at least in its adolescence, if not young adulthood, in many other countries. The Netherlands is certainly a leader in this area. I had attended a conference in Belgium and the thing that amazed me the most was the work being done by some of the eastern European countries like Slovenia and Bulgaria which are relatively poor countries. Some of these countries have incredible habitat and they’re spending money on crossing structures to maintain habitat connectivity across highways to a much greater extent than in the U.S. The people giving the presentations at the conference were the Transportation Ministers talking about why they do crossing structures vs. the researchers and conservationists here in the states who are making the case for crossing structures in this country. In other countries it is an integral part of how they do their transportation planning. And it is only just becoming a part of our transportation planning in the U.S.
One forum that provides a great opportunity to learn from shared research and information is the International Conference on Ecology and Transportation (ICOET). This conference is held every other year and it is THE conference at which road mitigation is discussed.
You spoke about Wildlands CPR’s work on road removal in U.S. forests. Why is this so important?
The Forest Service has more than $10 billion in road maintenance backlogs that needs to be carried out in order to prevent further erosion, sedimentation, and landslides. The road system costs more money than taxpayers can afford to maintain. Removing roads makes more sense economically and ecologically.
We have no qualms about the roads that are needed to move people but presently there is an unsustainable level of roads in the national forests. There are 380,000 miles of official forest service roads. If you add in city, county, state and federal roads – like a U.S. highway – plus the roads that are not on any map – you actually end up with more than 500,000 miles of roads on forest service lands. This is many, many times the size of the U.S. highway system.
So there is a need both to mitigate the roads that the Forest Service needs to keep and to remove the roads that they don’t need anymore. And what the Forest Service has found is that 80% of the use of the roads on national forest lands occurs on 20% of the roads – that’s only about 60,000-70,000 miles that are really needed to meet most forest transportation needs.
What are the motivations for road removal in more urban areas?
It really comes down to safety and money. The city of Seattle is spending $6 million over the next 20 years to remove roads to protect their municipal watershed. The alternative – the building of a water filtration system – would cost $120 million plus ongoing maintenance costs. By removing 10 miles of dirt roads in forested areas each year, they remove the main source of sediment into their municipal watershed. So by spending money to remove roads, they are saving money. They are keeping their water clean; they are putting people to work in high skilled, high wage jobs, and saving the taxpayers money.
What else can Leaf Litter readers do to educate themselves on this issue?
They can contact their state DOTs to find out what work is underway or being proposed. In a number of states there are transportation centers affiliated with local Universities that are conducting research and offering educational programs in this field.
They can also visit Wildlands CPR and learn about both the impacts of roads and the different ways that mitigation and restoration address those impacts. I also invite your readers to become members of Wildlands CPR.
Divorce Your Car: Ending the Love Affair with the Automobile, Katie Alvord, New Society Publishers (June 1, 2000)
The Geography of Nowhere: The Rise And Decline of America’s Man-Made Landscape, James Howard Kunstler, Simon & Schuster (June 1, 1993)
Apologia, Barry Lopez, University of Georgia Press (October 1, 1998)
Road Ecology: Science and Solutions
Wildlife and Roads: The Ecological Impact
Bryan Sherwood, David Cutler, and Jon Burton, ImperialCollege Press (2002)
No Place Distant Roads & Motorized Recreation on America’s Public Lands
David G. Havlick, Island Press (2002)
Flattened Fauna: A Field Guide to Common Animals of Roads, Streets, and Highways
Roger M. Knutson, Ten Speed Press (May 1, 1987)
Biohabitats Projects, Places and People
Projects & Places
Biohabitats, Inc. to Prepare Conceptual Design for Stream Restoration along Moose Lodge Tributary
The Harford County (MD) Department of Public Works has retained Biohabitats to develop a concept plan to restore 1000 feet of forested stream which has incised and is completely disconnected from the floodplain along the upstream portion of the project area. The concept plan will focus on minimizing impact to the existing tree cover, employing the use of natural channel design techniques, enhancing the riparian buffer, and working in concert with the existing surroundings. Biohabitats work will include performing an alternative feasibility study, developing a stream restoration concept, performing a natural resources inventory and a hydrologic analysis.
The recent removal of bridge abutments along the banks of Minebank Run in Baltimore County, Maryland, marked the final stage of a $3.1 million project to address serious erosion, flooding, and water quality issues in this tributary of the GunpowderFalls. Biohabitats designed, permitted, provided construction oversight and monitoring for nearly 8,000 feet of stream during the first phase of this project which was completed in 2002.
Biohabitats Awarded a 5-year $5 Million Contract with GSA (Schedule 899)
Biohabitats has established a relationship with the General Services Administration’s (GSA) Federal Supply Service. This 5-year $5 million multi-award schedule contract (GS-10F-0262R) will allow Biohabitats to provide environmental consulting services directly to a broad spectrum of federal agencies. More information about procuring services can be obtained through GSA’s procurement site GSA Advantage!
Biohabitats to Design Stream Restoration in Downtown Durham
The North Carolina Ecosystem Enhancement Program (NCEEP) is undertaking the restoration of Goose Creek in downtown east central Durham, North Carolina. Goose Creek is degraded due to encroachment and urban development in the contributing watershed. In conjunction with ongoing redevelopment plans in this urban area, the restoration project will help revitalize this neighborhood, as well as improve water quality in this water supply watershed.
Adaptive Management Approach Proposed for New National Aquarium Campus
To complement their world-renowned InnerHarbor facility, the National Aquarium in Baltimore is proposing to develop a new aquatic animal care and conservation education center on a site along the Middle Branch of the PatapscoRiver, Baltimore. As part of a Master Plan team led by Ayers Saint Gross Architects and Planners and Michael Vergason Landscape Architects, Biohabitats has been working to integrate an adaptive management approach into the design of the multiple-phase campus development plan that includes tidal wetland and woodland restoration, phytoremediation, and upland water treatment wetlands, all of which are aimed at regenerating ecological processes of a portion of the Middle Branch riparian corridor and shoreline.
Biohabitats’ Ohio River Bioregion, the lead firm for this design/build project taking place at the EllingtonAgriculturalCenter in Nashville, Tennessee, is currently working on the preliminary design for enhancement of Sevenmile Creek. The objectives for this project include improving bank stability and in-stream habitat, particularly for the endangered Nashville Crayfish. The work also involves riparian buffer establishment and floodplain basin improvements.
2nd Season of Noxious Weed Inventory and Treatment Now Underway
On June 6, our field crews arrived in Durango, CO, to begin our 2nd season of noxious weed inventory and treatment for the USDA Forest Service which augments our 2004 work to inventory fire-damaged portions of San Juan National Forest (Upper and Lower Missionary Ridge and East and West Vallecito) totaling 65,000 acres. We’re joined in this effort by Southwest Weed, Inc., out of Cortez, CO.
Private Ranches in Colorado Seek Biohabitats’ Expertise in Preparing Easement Documentation Reports
Conservation easements are becoming popular means for private landowners to protect their property from unlimited development. Landowners who donate or bargain-sell conservation easements to a qualified organization (e.g., a land trust or a public agency) and who seek a federal tax deduction for a charitable donation must hire an independent expert to prepare a report that documents the conservation values of the property (wildlife habitat, relatively natural plant communities, and open space.) Biohabitats’ Southern Rocky Mountain Bioregion office is currently preparing easement documentation reports for several private ranches in Colorado.
Biohabitats To Develop A Stormwater BMP Manual for Lake County, OH
Lake County Stormwater Management Division has retained Biohabitats to develop a Stormwater Quality Best Management Practices Manual for land development (and re-development) projects. These manuals will be used as both references and benchmarks for establishing guidelines and standards for Lake County, Ohio. The first manual section to be developed is Bioretention.
Biohabitats Participates in Restoration of Philadelphia’s Historic Awbury Arboretum
Biohabitats is working as a member of the Awbury Watershed Coalition with the Philadelphia Water Department to improve existing conditions at this historic property in Philadelphia. We developed strategies for control of undesirable invasive plants and reintroduction of desirable native species in existing wetlands, woodlands and meadows; developed an approach to redirect street runoff into a bioretention facility to be designed by Biohabitats and constructed by the Water Department with Biohabitats assistance; evaluating the redirection of other street runoff into a wetland on the Awbury property to improve the quality of the water as well as provide additional water for a pond on the Awbury property.
Biohabitats Updating Stewardship Plans for Stagecoach and St. Vrain State Parks
Colorado State Parks has an ambitious program of preparing and periodically updating resource stewardship plans for all state parks. Last year, Alan Carpenter – now the Senior Ecologist heading up Biohabitats’ Southern Rocky Mountain Bioregion office – prepared draft resource stewardship plants for several state parks including St. Vrain and Stagecoach. Plans are now being updated and are expected to be completed this summer.
Biohabitats Undertakes Feasibility Study to Determine Public Access to Conservation Area (photo)
The City of Cleveland has retained Biohabitats’ Great Lakes Bioregion office to develop a feasibility study for public access of Dike 14. The Dike 14 is 88-acres of closed confined dredge disposal facility. This site offers a unique setting for viewing wildlife habitat (i.e., birds). This is one of Cleveland’s initial projects under the lakefront development. The feasibility study will evaluate the public access to the site and enjoy the flora and fauna of a natural environment, ranging from relatively simple trails to more elaborate boardwalks, viewing stations and possible interpretive centers.
Biohabitats Preparing Vegetation Management Plan for Trinidad Lake State Park
Biohabitats’ Southern Rocky Mountain Bioregion office is preparing a vegetation management plan for TrinidadLakeState Park in the foothills of Southern Colorado. The park has important areas of pinyon-juniper woodland, riparian areas, and wetlands. One goal of the plan is to identify areas of tree die-back and wildfire hazard areas and to recommend steps that the park can take to deal with these issues. Another goal is to identify noxious weeds present at the park, the riparian and wetland areas where they are concentrated, and to make recommendations for weed management.
Pennsylvania Environmental Council Hires Biohabitats to Identify Site and Develop Plans for Wetland
Working with the Pennsylvania Environmental Council (PEC) and the Philadelphia Water Department, Biohabitats will evaluate a variety of potential wetland creation sites. We will conduct site studies and develop a detailed conceptual design for the creation of a one to two acre wetland focused on providing both wildlife habitat and water quality functions and values.
Biohabitats welcomes the addition of Stephanie Klein to our Chesapeake bioregion office. She has been trained as an Environmental Scientist in Northern California in the redwood region with an emphasis in Ethics. Her passion lies in green building including, permaculture site design, assessment, and implementation. She has done extensive work with invasive species identification and eradication in the redwood ecosystem for restoration efforts. Stephanie also served as a field assistant in Iceland evaluating the geomorphology and applied engineering techniques to the infrastructure of a geologically active area. Currently, Stephanie is at JohnsHopkinsUniversity perusing an MS in Environmental Science with an ecological management concentration.
Biohabitats Conducts Ecological Education Seminars for Baltimore City Middle School Students
As a result of a request from the Maryland Institute College of Art, Joe Berg, one of Biohabitats’ restoration ecologists, conducted three environmental education seminars for middle school students from the Booker T. Washington School in Baltimore. The purpose of the seminars was to provide over 60 students an introduction to ecological restoration and identify opportunities for careers in this expanding field.