Wildlife move both daily and seasonally to survive. However, the habitats animals rely on continue to be fragmented by housing, roads, fences, energy facilities, and other man-made barriers. As a result, animals are struggling more and more to reach food, water, shelter, and breeding sites.
Yet the need for wildlife’s ability to move may be greater than ever. The expanding U.S. population is bringing more people and development into conflict with wildlife and their historic habitats. And climate change is fundamentally altering landscapes, forcing many animals to relocate.
Habitat connectivity is defined as the degree to which the landscape facilitates or impedes animal movement and other ecological processes, such as seed dispersal. The National Wildlife Federation is confronting challenges to wildlife’s movement by improving habitat connectivity and providing safe pathways for wildlife on the ground, and developing conservation policies to ensure wildlife nationwide will always be able to get where they need to go.
Improving Wildlife Movement in the United States
The National Wildlife Federation and its partners are working to pass the Wildlife Corridors Conservation Act, a game-changing piece of legislation that could dramatically improve wildlife movement in the United States.
As habitat continues to be fragmented, degraded, and lost to development, the need for a coordinated connectivity network is growing. Better habitat connectivity will allow wildlife to migrate and disperse throughout the country with the changing seasons, boost biodiversity and resilience in degraded ecosystems, safeguard genetic flow between populations, and ensure species are better able to adapt to our changing climate. This work is an important and long overdue investment in the long-term health of wildlife populations and ecological processes.
Smart investment in habitat connectivity projects will help connect protected landscapes, such as the National Park System and National Wildlife Refuge System. Identifying prioritized corridors and key pinch points will improve connectivity that will benefit all species, from carnivores like the Florida panther to insects like the monarch butterfly.
The following are examples of current and proposed wildlife corridors:
- Elk and bighorn sheep: In the Upper Rio Grande Valley, the National Wildlife Federation is working with the New Mexico Wildlife Federation, Colorado Wildlife Federation, and other partners to establish federal protections for wildlife habitat connectivity across three national forests (the Carson and Santa Fe in New Mexico, and Rio Grande in Colorado) and the Rio Grande del Norte National Monument. This corridor would help species like elk, bighorn sheep, mule deer, pronghorn, lynx, black bear, mountain lions, and the rare Rio Grande cutthroat trout.
- Migrating birds and monarch butterflies: The Burnham Wildlife Corridor is a 100-acre landscape within Chicago’s Lakeshore Park featuring the prairie and woodland ecosystems that are native to this part of the Central U.S. The corridor runs right through the heart of the city. It is mainly used as a refuge for the three million migratory birds that pass through the Windy City each year, but also creates valuable butterfly habitat.
- Mule deer: In Wyoming, the Red Desert to Hoback mule deer corridor supports the longest mule deer migration in the U.S.
- Pronghorn and greater sage-grouse: The Northern Great Plains, which extend from Montana into Canada, support the longest pronghorn and greater sage-grouse migrations for both species. Taking a holistic approach to conservation, collaboration continues across the patchwork of public and working lands to sustain connectivity.
Enhancing Habitat Connectivity Through Wildlife Crossings
In addition to identifying and prioritizing corridors across the landscape, the National Wildlife Federation also supports infrastructure that enhances these efforts. This work consists of building overpasses and underpasses across highways that block mule deer and pronghorn migrations and creating culverts (pathways for water to flow under infrastructure) that allow turtles and amphibians to cross barriers safely.
Models for Connectivity
The following are examples of the types of infrastructure that can act as, or enhance, wildlife crossings:
- Banff: A system of wildlife crossings in Banff National Park across the Trans-Canada Highway has reduced ungulate-vehicle collisions by approximately 80 percent.
- Montana: A network of 81 wildlife crossings over and under U.S. Highway 93 in Montana, combined with more than nine miles of fencing, reduced deer-vehicle collisions by over 90 percent.
- California mountain lions: By creating a safe passage for wildlife near Highway 101, the Liberty Canyon Wildlife Crossing in California will be the largest wildlife crossing in the world, and a global model for urban wildlife conservation.
- Florida panthers: The Florida Department of Transportation has constructed numerous wildlife underpasses on busy state roads throughout South Florida.
- Turtles: In Massachusetts, a culvert was installed under Route 44 to allow spotted turtles to cross a dangerous roadway that bisected two populations.
- Salamanders: In Vermont, culverts installed along Vergennes Road have allowed hundreds of amphibians to safely cross the road, including blue-spotted salamanders, wood frogs, spring peepers, yellow-spotted salamanders, eastern newts, and four-toed salamanders.
- Moose: The Critical Paths Project in Vermont is identifying priority zones for wildlife crossings along the spine of the Green Mountains.
- Mule deer and pronghorn:
- The Wyoming Department of Transportation has constructed networks of crossings at Nugget Canyon and near Baggs over the last decade that have reduced ungulate-vehicle collisions by approximately 80 percent in these areas, and increased habitat connectivity for other species.
- The Trapper’s Point project near Pinedale, Wyoming, which includes six underpasses and two overpasses, has become world-renowned for reducing pronghorn and mule deer collisions and for protecting the “path of the pronghorn” migration corridor.
