大象传媒

Vast as Yellowstone National Park is, it鈥檚 not big enough for grizzlies. Before European settlement, an estimated 50,000 grizzlies lived in North America. They ranged from Alaska to Mexico, and across the Great Plains. Since then urban sprawl, deforestation, pollution, and climate disruption have destroyed almost all of their historic habitat. Researchers estimate that in the lower 48 states only 2 percent of the mountains, forests, and prairies that grizzlies once called home still support their seasonal diets and migration patterns. Now there are scarcely 1,000 grizzly bears in the contiguous United States, confined to a few pockets of protected wilderness in Idaho, Montana, Washington, and Wyoming.

But biologists like Michael Soul茅 and Reed Noss say grizzlies, wolves, and other big mammals shouldn鈥檛 be a casualty of modern society. They could make a comeback鈥攊f we give them what they need most: space. Soul茅 and Noss presented a new method for conservation in their 1998 paper, 鈥淩ewilding and Biodiversity: Complementary Goals for Continental Conservation.鈥� They discussed how the expansion of national parks and protected lands is necessary but only part of the answer. To piece back together the vast ecosystems that once stretched across North America, rewilding suggests an additional focus on reconnecting the scattered pockets of remaining wilderness, and on re-establishing predator populations. These methods have now evolved from conservation idea to practice and have become promising tools for fighting biodiversity loss.

Conservation is often about saving one dwindling population, one small remnant. Rewilding asks us to think big鈥攖o envision a continent-wide conservation strategy, with large core areas of protected land linked by lush, safe passageways for migrating species. Rewilding says that, although saving big spaces is critical, linking the spaces is just as crucial to stem rapid species loss.

Predator Power

Each creature plays a role in creating and maintaining the complex ecosystems we all live in. But Soul茅 and Noss found that carnivores are most often the head engineers that keep systems in balance. Without carnivores, Soul茅 says, ecosystems have a tendency to collapse. The gray wolves of Yellowstone, for example, helped regulate elk populations, which protected young plants like cottonwood saplings from overgrazing. But wolves were systematically hunted down in Yellowstone and disappeared from the park in 1926. Seventy years later, the ecosystem was collapsing: The elk population had exploded; young trees rarely made it to adulthood; birds, bugs, and other small animals had to compete for space; and soil was rapidly eroding, clouding streams and damaging fish habitat.

Wolves needed to make a comeback. In 1995, biologists from the U.S. Fish and Wildlife Service began reintroducing wolves to the park. About 10聽years later, Oregon State University conducted two studies to measure the health of the ecosystem. They found a direct correlation between the reintroduction of wolves and the recovery of Yellowstone鈥檚 nearly extinct cottonwoods. With wolves back, elk were less likely to forage in the open streamside areas, giving seedlings time to grow. With more cottonwoods and willows surviving, fewer areas suffered soil erosion, and birds, insects, fish, and other creatures benefitted from a larger variety of habitats for nesting and foraging. Park managers used wolves to help them restore habitats essential for the survival of hundreds of species.

鈥淲hen we are planning for the healthy functioning of ecosystems, we must consider the daily, seasonal, and generational needs of creatures,鈥� says Soul茅. 鈥淣ow the need for movement is even more critical because habitats are shifting rapidly due to climate disruption and stress. Therefore we must ensure that plants and animals have the ability to move long distances.鈥�

Wildlife Interstates

Many conservation leaders see the benefits of rewilding and have created groups that work on building major links between habitats. The conservation group Yellowstone to Yukon, for example, focuses on the western region of North America. They are working with landowners, tribal groups, and government agencies from Canada and the United States to weave together a corridor of restored and protected habitat for grizzlies, birds, and fish in the region. Their grizzly conservation strategy includes a suite of ideas for increasing the size of core protected areas, improving safety for bears as they migrate, educating local communities about grizzlies, and making it easier for the bears to cross major transportation routes.

Wildlands Network (WN), another organization applying the principles of rewilding, works with landowners and regional conservation groups in an effort to link together and protect pieces of land essential to migration and habitat restoration. Soul茅, who sits on the WN board of directors,聽says many ranchers and farmers realize that revitalizing a stream, for example, can help their business to be more successful in the long run. When working with landowners, Soul茅 says, WN often suggests making small but important changes in the way they manage their property or livestock that will allow grasses and vegetation to recover, eventually聽improving stream and soil health.

鈥淲e鈥檙e bringing landowners together across the country and saying, 鈥榊ou can help in making small changes in management to protect the world and save North America from what鈥檚 going to happen if we don鈥檛 do anything.鈥欌��

The long-term vision for WN is to create four major migration corridors that will extend over North America鈥檚 Eastern, Western, Pacific, and Boreal regions. Currently, they are focusing their efforts on the East Coast, from the Everglades and Appalachians to the Arctic; and the West Coast, from Alaska to Mexico and inland to the Rockies. WN is using scientific models and mapping to plan paths that help creatures migrate from one ecosystem to the next with the least possible interaction with industrial or urban areas.

Soul茅 believes that we can restore these pathways. We just need the commitment. He says that many people now recognize our ethical obligation to 鈥減rotect creation, and to maintain the biodiversity that is our final insurance against our own collapse.鈥�

鈥淔or example,鈥� Soul茅 says, 鈥渕ilitary planners now predict that the next big threat to our way of life is the lack of sufficient fresh water. Already water security is a major cause of conflict and unrest globally. If you鈥檙e an ecologist, you immediately realize that we really can鈥檛 protect watersheds and rivers if animals such as beavers and carnivores cannot be repatriated.鈥�

International governments and nongovernmental organizations have begun to understand that ecosystems do a lot of work for humans鈥攕uch as soil creation, crop pollination, and air purification鈥攁nd if we don鈥檛 protect the wild creatures responsible for maintaining these systems and cycles, we鈥檒l have to do that work ourselves. Through projects like The Economics of Ecosystems and Biodiversity study, an international research partnership, economists are documenting the many ways in which saving nature is cost-effective: For instance, it鈥檚 much cheaper to maintain marshland, which helps control floods, than it is to build dams and levees to handle stormwater.

Rewilding the World

The promise of rewilding has taken hold globally, and efforts to give creatures the space they need to migrate are underway in places as diverse as Nepal, Australia, and across Europe.

Author Caroline Fraser took a global expedition to visit rewilding projects, documenting her findings in the book Rewilding the World: Dispatches from the Conservation Revolution. Fraser found that the rewilding projects that work best are ones that incorporate communities into conservation work.

20,000 New Species Under the Sea
Who lives in the ocean? The world’s first census of the sea introduces thousands of new creatures, and the impact we’re having on them.

鈥淚f you don鈥檛 provide real economic opportunities for people to support and preserve wildlife and wild areas, then it鈥檚 just not going to happen,鈥� Fraser says. 鈥淭he problem is figuring out ways to do this that really let the communities themselves choose how they want to organize them.鈥�

Fraser found that the most successful programs were voluntary to join and beneficial to the community. The Lewa Wildlife Conservancy in Kenya, for example, invites local people to participate in wildlife preservation and ecotourism by turning over a percentage of their land to the conservancy. The landowners can still continue their pastoral traditions, and they gain shared revenue from ecotourism, which they use to fund a variety of community programs, such as tree nurseries and sustainable irrigation.

Since 1995, the conservancy has provided space and protection for animals like the black rhino, Grevy鈥檚 zebra, and sitatunga, a species of antelope. The sanctuary now includes more than 62,000 acres of grassland, acacia groves, and wetlands.

Reconnecting

For too long the Western world has tried to live separately from鈥攐r in opposition to鈥攏ature. Ignorance of the deep interconnectivity of life is dangerous not only for wolves, bears, and zebras but also for us. As our air and water grow dirtier and our soil thinner, animal species suffer, but ultimately so will humans unless we act. Rewilding offers a way to revitalize biodiversity, rebuild our environment, and reconnect on a large scale what has become disconnected: humans and natural landscapes.

Interested?

• We take for granted that humans have rights. Courts say corporations do, too.
  Now, there鈥檚 growing interest in rights for Nature and animals.
• 大象传媒 asked Jane Goodall to tell us what we can do in our everyday lives to care for the animals we love.
• All around us are radiant species. What can the first peoples teach us about restoring our relationship with animals?