Wildlife Bridges: Safe Passage at Wildlife-Human Crossroads

By Neva Knott

In my recent post, “Losing Hope,” I gave the analogy of deer encroaching on yards, specifically in the town of Ashland, Oregon, as a way to talk about common sense and living in harmony with nature even when planning human spaces and endeavors.

As populations increase–those of human and other species–and natural resources decrease, co-habitation becomes more of an issue. Human development constantly destroys and fragments non-human habitat. Then what? Where do the animals go? How do they traverse landscapes to find food, water, shelter, and mates?

In the extreme, other species die because of this.

In another version of the extreme, or possibly the common sense to wildlife scenario, non-human species–deer, bear, cougar, coyotes, and wolves, to name the Oregon/Western states usual suspects–come on to territory now considered human, continuing to look for the resources they previously found there. In the case of Oregon’s wolves, this is the rub…ranchers don’t want wolves near livestock, but when wolves are forced out of their native feeding areas or have to travel fragmented landscapes, often crossing open range, they intersect with these human spaces. Though the livestock kill, or depredation, rate is very low, it’s a heated issue and one that governs wolf management.

Deer, bear, cougar, coyotes also make their way onto human landscapes, looking for food and water–because their foraging habitat has been destroyed or replaced with ranches, houses, shopping malls. The saddest example I’ve witnessed was a family of mule deer standing between Wal-Mart and the gym in Redmond, Oregon, train tracks behind them and pretty much surrounded by parking lots.

As these animals, and other species like marmot, field mice, frogs, birds, bats…move around to forage, they need cover for safety. Imagine a field mouse trying to make it across a large lawn with no shrubbery to hide under and with all sorts of predators above. This is the issue with habitat fragmentation.

Roads are one of the biggest threats to wildlife movement. In fact, I’ve heard it said that deer are the most dangerous animal in Oregon because so many of them cause car accidents when crossing roads.

Recently, wildlife managers/agencies in a handful of places have installed wildlife bridges as a way to provide habitat corridors, giving safe passage to our wildlife friends, and even providing habitat as part of their construction.

This video from Conservation Northwest explains the concept and shows construction on the I-90 corridor project in Washington State:

In 2012, Oregon Department of Transportation build the state’s first wildlife underpass along a high-collision stretch of Highway 97, a bit south of Redmond where I saw those poor stranded deer.

us 97 corridor

Aerial view of Highway 97 underpass. Photograph courtesy of ODOT.

Recently, in a follow-up piece in the Oregon Public Broadcasting’s Field Guide the rationale for the project was explained:

“Mule deer west of the Cascades typically migrate between the mountains in the summer and the lower elevation lands in the winter. Highway 97 presents a stark barrier in that journey…When deer need to get where they’re going, they often must conquer an obstacle course of fences and roads. Miles upon miles of human made barriers snake across even the most wide-open landscape.The deadliest obstacles they confront are dangerous, virtual walls of flying metal: highways full of high-speed traffic: ‘You have stranded herds of animals,’ says Kevin Halesworth, a biologist with the Oregon Department of Transportation.  ‘As the traffic level increases, the deer are less able to cross the highway until it gets to a point where from studies, the deer just won’t cross at all any more.'”


Mule deer using the underpass. Photograph courtesy of ODOT.

The underpass created a connected habitat–or as it is often termed, habitat connectivity, for the mule deer, and created safe passage for both wildlife and motorists along the shared deer migration and Highway 97 corridor.

In a recent project status update published in The Bend Bulletin, state scientists reported an average of 95 deer per year were killed by car collisions before the underpass. Now that animals are using the underpass, the number of car-collision deaths has dropped “drastically.” In the same article, a scientist for Oregon Department of Fish and Wildlife explained, “hundreds of similar projects around the country have shown an 85 percent or better decrease in the number of animal-versus-vehicle collisions.”

Mule deer aren’t the only travelers through the underpass. Cameras track usage. ODOT told Oregon Public Broadcasting bobcat, raccoon, turkey, weasel, badger, coyotes, bears and more use the crossing: “We also had a bobcat that was not only using the structure to cross the highway, he was actively hunting in here and we have pictures of him capturing prey.”

The Highway 97 underpass is Oregon’s first wildlife corridor project. Animal Road Crossing–ARC–an agency dedicated to designing and building wildlife passageways, gave it the Exemplary Ecosystem Initiatives Award in 2012. ODOT is planning a second project along Highway 97, an overpass, which is scheduled for completion when funding is secured.


Illustration courtesy of ODOT.

Several US states and many places in Canada have installed wildlife bridges. You can see pictures of some of them here in this publication from Oregon Department of Fish and Wildlife and on the website for ARC. The Center for Large Landscape Conservation published a reader-friendly report on the science of and need for wildlife connectivity, citing climate change as a key factor to consider in keeping wildlife habitat intact.

The issue of wildlife corridors is an aspect of defining critical habitat during the land use planning process, one the Western Governors’ Association is taking to task. The Association, in December 2013, launched the “Crucial Habitat Assessment Tool (CHAT), a cooperative effort of 16 Western states to provide the public and industry a high-level overview of “crucial habitat” across the West.”

One of my favorite connectivity projects is Yellowstone to Yukon, an organization with the stated vision of, “An interconnected system of wild lands and waters stretching from Yellowstone to Yukon, harmonizing the needs of people with those of nature.”


The Y2Y area is outlined in white. Image courtesy of Yellowstone to Yukon.

The organization also calls their project “The Geography of Hope,” in that, “Stretching some 2,000 miles in length (3,218 km), the Yellowstone to Yukon region is one of the last intact mountain ecosystems left on Earth. It is home to the full suite of wildlife species that existed when European explorers first arrived and it is the source of clean, safe drinking water to 15 million North Americans.”

Wildlife bridges are common sense, don’t you think?

A Wolf’s Eye


 Tagged Wolf OR-14. Photo courtesy of Oregon Fish and Wildlife.

By Neva Knott

I became interested in the history of Oregon’s wolf bounty—a sanctioned act to eradicate—kill off—the wolf population to make way for ranching—while reading and teaching Molly Gloss’s The Jump-Off Creek. I’d just moved to Redmond, a farm town in Central Oregon, and liked the idea of an Oregon author writing the story of the early days of life in that part of the state. Since then, throughout the coursework in my Master’s in Environmental Studies program, I’ve had the opportunity to read much about wolves, and to study the current conflict between the wolves that have migrated back into the state and the ranchers who feel they now own that landscape.

 Aldo Leopold is a widely known ecologist. One of the things he’s famous for is speaking out about the necessity for humans to realize, and try to accommodate, the needs of other species. The following passage marks the turning point in Leopold’s thinking, toward that ideal:

           “In those days [1920s] we had never heard of passing up a chance to kill a wolf. In a second we were pumping lead into the pack, but with more excitement than accuracy…When our rifles were empty, the old wolf was down, and a pup was dragging a leg into impassable slide-rocks. We reached the old wolf in time to watch a fierce green fire dying in her eyes. I realized then, and have known ever since, that there was something new to me in those eyes—something known only to her and the mountain. I was young then, and full of trigger itch; I though that because fewer wolves meant more deer, that no wolves would mean a hunter’s paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.”

from The Sand Country Almanac, 1966.

Recently, I found myself engaged in a discussion based on the passage—the questions raised were, Is nature ethically and politically silent? Does it have value apart from human meaning? Two huge, philosophical questions, right? Two of the big, essential questions that drive much of the debate about environmental issues. Here’s my answer, or at least my pondering…

I don’t think that nature is silent; however, to hear the messages, humans must listen. Nature speaks in cycles and processes. Clear messages are thus sent about what it takes to maintain vitality, and what it means to live and die within the systems of nature. Leopold’s description of the wolf’s death is a perfect example of nature sending a message that was heard by a human. This passage is also a perfect example of the ethical and political aspects of such messages. The choice to kill for sport and thereby end two generations of wolves is an ethical choice; Leopold’s act then became political when he was motivated to change his ideology as a naturalist and a hunter after watching the light leave the mother wolf’s eyes.

Wolves are not intrinsically cruel. They, in fact, are quite loving and social animals; in fact, some wolf experts suggest that humans can learn much about family bonds, loyalty, and social structure from this species. (Now there’s a message from nature). Leopold meant that he saw a message coming through the wolf’s eyes, some deep, deep meaning in her experience of the event. This message, Leopold realized, was bigger than human experience. He then was left to consider the implications wrapped within. No, in this case nature was not silent. Leopold’s account illustrates that nature has value apart from human meaning.

It’s no accident that this Leopold passage is at the core of Green Fire Production’s film, Lords of Nature. This documentary richly portrays the role of wolves as top predators in nature.

Just as I began my wolf research, I heard a public radio broadcast of former Governor Barbara Roberts speaking to the Portland City Club. She spoke of coming into adulthood with few women role models in positions of power. She remembered completing a Girl Scout badge on women of significance, such persons as Florence Nightengale. Roberts remembered feeling inspired by the women she researched, but also feeling that they were far away. In her comments to the City Club, she recounted the deep feeling she’d carried with her as she made her way to Governor that it was a time of change, and that she and other women had the opportunity to break ground—if they chose to seize the moment.

Oregonians have a similar opportunity right now to break ground in terms of human progress in relation to the natural world. The days of the wolf bounty are long gone. Will we seize the opportunity to live alongside wolves, who bring health and balance to natural landscapes, or will we continue simply to pump lead into the pack?