Crossings and Wildways
Where Wildlife Meets the Road
By Karen L. Monsen
“Humans, too, find freedom and peace of mind in big, connected landscapes.” ~Wildlands Network
Where animal paths and roadways cross, collisions often occur. The U.S. Department of Transportation estimates that nationwide, crashes involving animals cost $8.38 billion annually and average 26,000 human injuries and 200 fatalities. To reduce animal-vehicle collisions, state highway departments, wildlife resource managers, and nonprofits are working together to improve wildlife passage routes and connect habitat across state boundaries into safer migratory and movement corridors.
Utah Roadkill Costs
A Utah Department of Transportation (UDOT) report, co-authored by independent wildlife researcher and former Utah State University professor
Dr. Patricia Cramer, noted that 3,232 wildlife-vehicle collisions were reported in Utah during 2015, costing over $66 million with approximately 100 human injuries and one fatality. Using a conversion factor counting carcasses, this report estimated 17,000 mule deer were killed in Utah collisions in 2015.
Cramer asserts, “Vehicle collisions with wildlife pose safety risks to the motoring public, which lead to significant economic losses and threaten wildlife populations.” The UDOT report further revealed that when wildlife exclusion fencing and crossing structures are working correctly, collisions are reduced on average by 86 percent.
Overpasses and Culverts
The first wildlife overpass in the U.S was constructed in Utah in 1975 over I-15 south of Beaver. The location was selected based on an abundance of deer and specific land features. According to Assistant Habitat Manager with Utah’s Division of Wildlife Resources, Rhett Boswell, “At the time when the overpass was built, the Beaver area was said to have the largest mule deer population in the world.” The crossover spot itself is at the top of a hillside ridge forming a natural bridge where the roadway cuts crucial mule deer winter range.
A camera on the overpass captured an annual average of 2-4 bull elk, approximately 400 mule deer, and other animals including livestock using the crossover. Just north of this overpass, two culverts dubbed “the Wildcat structures” are the most-utilized animal crossings in Utah. Dr. Cramer’s work for UDOT recorded 16,606 mule deer passages through these two culverts during a 3-year study.
Pahranagat National Wildlife Refuge (NWR)
Even small habitat parcels become critical links for larger migratory routes. Pahranagat NWR, established in 1963, is a relatively small national wildlife refuge at 5,382 acres. Located in Nevada along the Pacific Flyway, approximately 90 miles north of Las Vegas on U.S. Highway 93, it is part of the Desert National Wildlife Refuge Complex. Pahranagat attracts migratory birds to its lakes and wetlands, and offers wildlife-viewing opportunities, hiking, and camping to more than 30,000 people annually.
Dan Balduini, Public Affairs Officer for the Desert National Wildlife Refuge Complex and the Southern Nevada Fish and Wildlife Office, states, “The spring-fed lakes and riparian areas make Pahranagat NWR stand out in comparison to the surrounding desert.” The refuge provides wildlife with habitat and food resources, while permitting hunting and fishing in designated places during specific times subject to applicable state, federal, and refuge regulations. Fragmented and small refuges, like Pahranagat, become even more valuable when connected to nearby public lands and privately-owned undeveloped properties.
Wildlands Network and Wildways
Wildlife managers dedicated to sustaining healthy animal species and transportation professionals focused on reducing roadway collisions are finding common ground with Wildlands Network, a non-profit striving to link public and private lands into wildlife corridors.
Established in 1991 “to reconnect, restore, and rewild North America so that life in all its diversity can thrive,” the Wildlands Network (wildlandsnetwork.org) envisions four corridors called wildways across the U.S. The 6,000-mile Western Wildway stretches from Mexico to Canada and includes most Utah public lands, national parks, monuments, and forests interspersed with private properties.
Wildlands Network Western Director Katie Davis acknowledges, “Ecological boundaries are in no way reflected by our political boundaries. While this amount of area seems immense, remember that we are looking at wildlife habitat and movement on a continental scale. We’re trying to protect the last, best places and the connections between them.”
In Arizona, Davis explains, “the wildway stretches from the Grand Canyon ecoregion, which is centered around Grand Canyon National Park, across the Mogollon Rim, into the Sky Island region, which includes lots of BLM land and the Coronado National Forest. It’s hard to conceptualize how all these landscapes fit together until you see it from the air. But the variations in topography and water availability and plant life create unique ecological zones where wildlife species interact, contributing to great biodiversity.”
By understanding wildlife movements and providing safe roadway crossings, wildlife managers and transportation professionals can reduce costly animal-vehicle collisions. Furthermore, by connecting natural habitat into migratory corridors and wildways, animals and humans will continue to roam freely.
The Wildlife Corridors Conservation Act, a bipartisan effort to give federal agencies tools and resources to come up with workable solutions to protect wildlife corridors and connectivity, will be reintroduced in Congress in 2018.