We are in the middle of the earth the sixth extinction crisiswith one of five migratory species are at risk of extinction. Much of the erosion and even extinction of species is due to range contraction, habitat loss, and fragmentation caused by human developmenturban and suburban development, and irresponsible agricultural practices.
If you live anywhere in or near a suburban or urban area in the United States, chances are you have seen or at least heard of seeing carnivorous mammals like coyotes and bears in your neighborhood. As we take over more of their territory, they will enter ours, often in search of food.
Bears use a renovated culvert. Photo via NPS.
The clearest evidence of unwanted interactions between humans and wildlife occurs on our roadways. Every year in the United States, vehicle animal collision caused about 200 human deaths, millions in animal deaths, tens of thousands of human injuries, and billions of dollars in damage to cars and other property.
It’s just the roads. There are broader connectivity issues too. While there are vast areas of protected wilderness across the country dedicated to preserving Gray Bearwolf, pronghornWhile feral cats and other large animals are safe, they are often isolated in such protected areas, unable to access other individual animals or herds in other protected areas, making these groups susceptible to inbreeding, not to mention disrupting their natural hunting and migratory rhythms.
A bipartisan infrastructure bill passed in 2021 contained $350 million for wildlife roadsThese structures are built under or above roads, have fences that direct animals to safety, and are said to reduce collisions between wildlife and cars by up to 97%.
These crossings, built over or under human-made intrusions in the landscape such as roads, can include underpasses or viaducts for mammals and amphibians of all sizes, or bridges, typically for larger mammals. These crossings provide safety and connectivity for animals whose habitats are fragmented by roads and buildings. (The largest crossing ever built is currently under construction in California. See its progress.) This).
Today, a network of activists and policymakers is working to help heal and create connections between wild areas across the United States for animals to move, as well as make it easier for animals to move across major roads that cut through their habitats.
The culvert was renovated for wildlife. Photo via NPS
Work for the wolf
“We are really fortunate to have a partner in the North Carolina Department of Transportation,” said Will Harlan, Southeast regional director and senior scientist at Center for Biodiversity“The team there understood that building wildlife corridors along Highway 64 had the potential to save species, benefit other wildlife, and prevent human deaths and property loss.”
There are now fewer than 25 red wolves left in the wild, and Harlan said five have died in the past year along this stretch of highway, the longest in the state, running 604 miles from the Tennessee state line to the Outer Banks. Red wolves once ranged from Texas to New York. Today, the only place red wolves still exist in the wild is the 3,200-square-mile Abermarle Peninsula in North Carolina.
“In North Carolina, we have an incredibly high rate of vehicle accidents, and seven percent of all traffic accidents are wildlife collisions,” he said. In 2010, the Department of Transportation was considering widening the highway; they identified five major animal crossing areas. Harlan is currently in the process of raising a large amount of money to build crosswalks, with the goal of advanced $2 million on August 1.
“Wolves are my personal priority, but of course, I would be delighted to see other species like [the] 700-pound black bears, rare snakes and turtles, beavers, lynxes and dozens of other species can safely cross the road.”
An old Forest Service road in northwest Montana was demolished to improve fish and wildlife habitat. Photo by Adam Switalski.
Recreate landscape link
Grizzly bears, wolverines, bobcats, Mexican wolves, and salmon are particularly vulnerable to mortality or severe isolation due to the loss of natural connections between landscapes in the Northern Rocky Mountains, New Mexico, and Arizona, where WildEarth Guardian focus efforts on recovery and safety.
“That often means protecting key areas from logging projects and pushing the agency to clear roads and trails for motor vehicles instead of building and constructing new ones,” said Adam Rissien, director of rewilding at WildEarth Guardians.
This type of work often requires secret surveillance of trails. Last winter, WildEarth discovered illegal activity in the Kaniksu area of North Idaho with the help of LightHawk, a nonprofit conservation aviation organization that sponsored a surveillance flight. The use of aircraft as an asset in conservation is on the rise, especially with volunteer groups like LightHawk, which taps its network of more than 300 pilots who donate their expertise, time, aircraft, and fuel to support reconnaissance flight operations with organizations like WildEarth.
An old Forest Service road in northwest Montana was demolished to improve fish and wildlife habitat. Photo by Adam Switalski.
Volunteers also contributed photos of vehicle tracks in the snow in critical habitat for wolverines, grizzly bears, lynx and mountain goats. This disturbance could jeopardize the survival of all these species, especially as many abandon or move their dens, reducing their ability to reproduce.
Rissien said WildEarth is currently in the process of “evaluating the possibility of litigation to protect the habitat.”
The group has also challenged a Forest Service logging project outside Yellowstone National Park in the Custer-Gallatin National Forest that it says would reduce the security of grizzly bear habitat. Last year, 50 grizzly bears died in the park. If approved, the project would clear more than six square miles of land and open up another six square miles of old-growth forest.
“Yellowstone grizzly bears need more habitat to recover, not less,” said Rissien.
A mountain lion uses a National Park Service crossing in the Santa Monica Mountains. Photo via NPS.
Using science to drive policy
Development isn’t the only enemy of wildlife safety. Climate change and how it affects where animals can and want to live is adding to the challenges wildlife face.
“Protecting and improving wildlife connectivity will help us combat extinction and the climate crisis,” said Tiffany Yap, PhD, senior scientist in the Center for Biological Diversity’s Urban Wildlands Program. “As climate change intensifies and resources on the landscape shift, connectivity will help wildlife find the resources they need to survive and keep our ecosystems healthy.”
Yap said enhancing connectivity across roads and landscapes would be most effective through science-based policy.
Bobcat in the sewer. Photo via NPS
In 2022, the Center co-sponsored AB 2244Safe Roads and Wildlife with Wildlands Network Act. California Governor Gavin Newsom signed the bipartisan bill into law and requires Caltrans to identify wildlife barriers on roads and build crossings when building or improving roads.
The Center also co-sponsored AB 1889Also known as the Wilderness Network Roaming Spaces Act, it aims to reconnect fragmented areas for slow-moving cougars and salamanders.
“Overdevelopment and careless development along with our roads have disrupted habitat to the point where animals cannot find food, shelter and mates,” Yap said. “This act requires local governments to consider and mitigate impacts on wildlife movement and habitat connectivity as part of the conservation element of their overall plans.”
The code encourages wildlife-friendly fencing, reducing light pollution, and planting drought-tolerant native plants to attract native pollinators. (Wildlife-friendly fencing is highly visible to animals and birds and allows animals to safely pass through or under the fence; typically this means a 40-inch fence with a minimum spacing of 12 inches between wires. Light pollution can be reduced by minimizing lighting, using LEDs, orienting lights downward, and using lampshades or covers.)
“By maintaining healthy ecosystems, we can better maintain the common benefits that humans receive from them, such as clean air and water, buffers from extreme weather, crop pollinators like bees, and pest control like bats, which prey on crop-eating insects,” Yap said.
