Our national parks aren’t only “America’s best idea,” as environmentalist and nature writer Wallace Stegner called them. These special places are the backbone of national conservation programs. National parks are key to ensuring the health of the environment because they play a critical role in maintaining robust ecosystems, providing clean air and supplying clean water; and they are where much of our natural resources are located and some of our most iconic wildlife live.
Many national park units, of course, are too small to sustain long-term, viable animal populations. For example, Pennsylvania’s Thaddeus Kosciuszko National Memorial is the smallest national park unit at just 0.02 acres. But if we could establish ecological corridors for big mammals between some of the larger ones—such as between Glacier, Grand Teton and Yellowstone National Parks and between Mount Rainier and North Cascades National Parks—we would not only enlarge many wildlife populations, but also allow species to shift their geographic ranges more readily in response to climate change.
Could the places now fondly known as our best idea now become the sites for another, huge, national concept and further contribute to our national identity?
Interpark corridors for conservation
Across the country, national parks offer some of the last suitable habitats for a number of species and are home to creatures that exist nowhere else in the world. They play a major part in saving some of the rarest animals and plants from being lost forever.
Take grizzly bears, for instance. They make their homes in only five regions of the country; and three national park sites—Glacier, Grand Teton and Yellowstone—have been key to their survival. California condors are another case in point. These birds once ranged throughout the skies of western North America; but by 1982, only 22 remained. A variety of human activities led to their population decline, including the use of lead ammunition, which poisons the animals the condors feed on. Now, the birds are making a comeback, thanks to a captive breeding program by the U.S. Fish and Wildlife Service and successful reintroduction efforts at regions around Grand Canyon National Park and at Pinnacles National Park in California. These efforts have boosted the bird’s numbers to nearly 500.
And many bats around the country have been significantly affected by white-nose syndrome, a disease that has continued to spread at an alarming rate since it was first discovered in the winter of 2006 in New York state. National park sites, such as Mammoth Cave in Kentucky and Great Smoky Mountains in North Carolina and Tennessee, are particularly important as protected refuges for the bats that remain; and they provide places where researchers can monitor and study how the disease affects these animals. Just the fact that those caves are safeguarded is a chance for these species to hold on in the face of this dire disease.
Now, a new study published on Jan. 11, 2023, in the journal Scientific Reports offers us some extremely good news on how national parks can play an even more enhanced role in conservation. Researchers, drawing heavily upon patterns of species loss over time in habitat fragments around the world, found that improving ecological connectivity, known as “corridors” or “linkages,” among several of the oldest and largest national parks in the western United States would greatly extend the time that many mammal species populations can persist.
The authors of the Scientific Reports study discovered that linking Yellowstone National Park in Idaho, Montana and Wyoming with Glacier National Park in Montana—and joining Mount Rainier National Park with North Cascades National Park (both in Washington state)—would increase the long-term persistence time of mammal species by a factor of 4.3 relative to the continuance of species in fragmented, individual parks. And, their findings also show that these corridors would not only increase the longevity of wildlife populations, but also allow species to shift their geographic ranges more readily in response to climate change.
The proposed corridor networks would cross two- and four-lane highways, which would require multiple ecological bridges over and under the roadways. Fortunately, highway authorities in the western U.S. and Canada are beginning to construct such over- and underpasses for wildlife. However, a much greater effort will certainly be required if we are to reduce the known adverse impacts of highways on species movement and dispersal.
Previous to this study, it was known that ecological corridors help animal populations to survive longer, but most of the evidence was based on small-scale experiments. There were few assessments of the value of ecological linkages on a large scale, such as this one. The scientists hope that enhancing ecological connectivity between protected areas in the western U.S. and Canada will serve as a significant and useful template for major biodiversity conservation initiatives—both nationally and worldwide—in the 21st century.
International dreams for connectivity
Eliminating barriers of movement between big national parks and more carefully managing land-use along such pathways could be essential for the survival of many mammal species. Establishing an expanded, protected-area network based on identified mammal pathways and incorporating adjacent wilderness areas would greatly enlarge the available habitat for mammal species. And this would have a very positive effect on species persistence time.
This is a vision that needs to grow. And, there are signs that it is.
The Canadian federal government is currently preparing a strategy for habitat connectivity and investing in protecting and restoring habitat corridors. An effort to connect Canada’s Yukon Territory to Yellowstone National Park in the northern Rocky Mountains has made considerable progress. In addition, the Global Biodiversity Framework agreed upon at the COP 15 United Nations Biodiversity Conference in Montreal, Canada, places a great emphasis on restoring habitat connectivity worldwide. The researchers say that their results provide new knowledge to guide action by nations looking to achieve the 2030 target for habitat connectivity in the coming decade.
But oddly enough, more than a quarter of a century ago, the boldest vision yet was first articulated. Michael Soule, professor emeritus at the University of California, Santa Cruz, who passed away before the Scientific Reports paper was completed, advocated to establish a protected-area network that would extend from the top of Alaska down to the southern tip of South America at Tierra del Fuego.
If such a big dream ever comes true, I’m sure that such a conservation corridor would change the fate of countless numbers of creatures.
Here’s to finding your true places and natural habitats,