WILDLIFE CORRIDORS

©By Susan B. Eirich, Ph.D.

In 1991 a young gray she-wolf named Pluie was trapped and radio collared. Starting in Alberta, Canada, she traveled 3800 square miles in nine months, an area ten times larger than Yellowstone. She had interacted with 5 packs on her travels before she was shot by a hunter in Kootenai in 1995. She is not alone. Lynx make epic travels of hundreds of miles as the crow flies. Recent genetic studies confirm that these journeys are quite common. Traveling far and wide, the lynx interbreed with others of their kind along the way - the genes flow across space and time to be found thousands of miles away. Restless male wolverines range across territories of 1500 sq km. Eagles fly along the Rocky Mountains from the southwest United States clear up to the arctic. Salmon migrate from the headwaters of rivers to the oceans and back to the mountains, bringing nutrients from the sea in the form of their bodies as they return. Antelope migrate from the Grand Tetons to the sage and grasslands of southern Wyoming and back, a journey of 170 miles each way. There is some evidence that elk would migrate too, but Jackson lies in the way.

We are gathering evermore data that it isn't just butterflies or birds that travel long distances. Over days to years to generations, animals roam. They look for food, mates, new territories to set up home. They roam daily seasonally as food sources change. They move to survive local disasters. They move to survive the winter, to find mates, to locations with enough food to fatten up for breeding and raising young. They roam over the seasons, over the year, over a lifetime and over several generations, repopulating decimated habitat or settling new areas. Plants migrate too, a slow creep not always visible to our short human time perspective. Living things move from necessity ­ in many cases it is migrate or perish. It is a major means of adapting and survival. Migration and motion is the nature of nature. Species cannot survive over time in the islands of habitat we have allotted them.

Human development is increasingly preventing animals and plants from moving, cutting them off from others of their own kind, interfering with feeding and mating and migration patterns, some of them thousands of years old. It is forcing inbreeding, decreasing genetic resilience; decreasing their ability to adapt to local catastrophes or changes such as a new road in an area already cut in half and half again. Roads, railroads, clear-cuts, developments, agriculture, cities, subdivisions, dams - we are effectively cutting up habitat into isolated patches and islands surrounded by houses, cities, roads. The total miles of road on USFS alone are now greater than the total miles of the US Interstate highway system, and road construction continues to be allowed on tens of millions more acres of our public lands.

There are always natural catastrophes in the form of floods, landslides, drought, disease. Wildlife can recover from or adapt to these over time, as they can from a moderate amount of human development. It is the scale and speed of human development that is disrupting the web of life in ecosystem after ecosystem. The fragmentation of habitat is a major cause of the increasing rate of extinctions.

In the early 80's scientists studying species in many different places began to realize they were all reporting the same thing - a repeated pattern of extinction in place after place, species after species. In 1985 William Newmark published a startling landmark paper documenting the loss of mammal species in all but the largest North American park complexes. The rate of local extinctions was inversely related to their size of the park - as the area decreased, the extinctions increased. Even areas the size of Yellowstone are not big enough to facilitate the flow of genes, the flow of life over time. In our conservation planning we have not understood the large scales of space and time over which ecological processes work, and ecological stability depends.

The good news: there is great hope in what was only recently considered an unattainable possibility: designing and implementing large, regional, networks of wilderness reserves, connected by "animal highways" - corridors for wildlife in which to naturally and safely pass.

Some 25 years ago Reed Noss did a doctoral dissertation recommending a statewide system of connected regional reserve networks to protect Florida's disappearing panthers and black bears. Too radical for its time, it was shelved. But in 1991, pushed by worried Floridians, the state government passed a bill allotting $3 billion over 10 years to buy lands for just this type of corridor. The result is the Greenways programs and the Florida Ecological Network, supported by government and conservation agencies alike. Florida now has more than half its land set aside in reserves, with virtually no displacement of people, though some roads may have to be closed.

In 1993 Dr. Harvey Locke put together two crucial observations: the entire length of the Rockies functions as one great mountain ecosystem; and along its length large wilderness areas were already set aside in the form of national, state and provincial parks and reserves - and the Yellowstone to Yukon Conservation Initiative, or Y2Y, was born. Its mission is to "identify biologically critical movement corridors throughout the system, and use them to link the reserves together, while preserving and enhancing the social and economic fabrics of communities in and around the corridors."

The Y2Y extends from the Greater Yellowstone Ecosystem, 2000 miles north to the MacKenzie Mountains in the Yukon. It crosses the international boundary and brings together a network of 270 conservation organizations and millions of individuals. It has been approved by the national park systems of both the United States and Canada. Although any conservation initiative this size and involving so many competing interests is bound to be controversial, it is based on solid science and a positive, inclusive, model that includes the needs of people in the region as a crucial component.

Following are two examples of the extensive, detailed science on which the Y2Y initiative is based. The Jackson Hole Pronghorn Study, published by the Wyoming Cooperative Fish and Wildlife Research Unit, tracked the local antelope migration mentioned above. The antelope "need to migrate an extremely long distance through difficult terrain..." The "migrations between summer and winter range often follow traditional routes that are learned and passed on from mother to young... There are 47 fences perpendicular to their migration route just between the south end of Mesa and Kelly. The antelope must cross at least 35 of these." Also along the traditional migration route are a number of bottlenecks, some natural, some man-made. Trapper's Point near Pinedale is a "naturally occurring bottleneck approximately one mile wide...Archaeological records suggest pronghorn have migrated through Trapper's Point for thousands of years ­ a recent dig... documented a 6000-year-old pronghorn kill site in the core of the bottleneck... The kills occurred in late-March or early April, corresponding with the timing of modern-day pronghorn migrations through this corridor. "

Most of the lands surrounding Trapper's Point are private lands that have been subdivided, fenced and developed. To date this "has narrowed the effective width" the antelope can use to approximately 1/2 mile. "Alternative migration routes appear to be unavailable or inadequate..." To the south, "natural gas development, proposed gas exploration, and subdivision development on private lands threaten winter ranges and migration routes." Part of our National park diversity depends on what happens 150 miles away. It is one system - one part can't survive without the other.

Migration pathways and bottlenecks are only one factor to be taken into considering reserve size and design. Large-scale ecological processes are as essential to the survival of a rich biodiversity as are the species themselves. For example, with the help of satellite imaging it is now possible to identify a specific form of nitrogen in high mountain valleys that could have originated only in the ocean. They were carried along streams up to the headwaters in the form of migrating salmon. From there they were carried even further, above the headwaters, to grizzly resting grounds in the high shrub country. These nutrients were also found along a very large networks of trails as the bears carried them, ate them, dropped parts, defecated along the way. The curves in the nitrogen samples away from the streams matched the distribution of the bears. A study in progress has found that the growth rings of trees near streams with salmon and bears are 30% wider then those without salmon and bears. As an additional service big bears can eat 300,000 to 400,000 berries a day, passing then along with natural fertilizer as they defecate in their forays. Between the salmon and the berry patches the bears offer a one-species reforestation and forest fire recovery service. Meanwhile the salmon bring a "care package" to many other species as well. Where the salmon die in massive quantities, maggots devour the carcasses and move towards the forests in waves of wiggling nutrients, where the birds come to feed gorge themselves. Along the way wolves, raccoons eagles, osprey, otters and dozens of other species feed on the salmon over their life cycle. The streams wash nutrients down to the sea, the salmon bring them back up. This is an example of a pattern called nutrient cycling.

Ecosystems are immensely complex in their interconnections. We need to study individual species in intensive detail. Different animals have different needs. Pine martens do not cross treeless expanses much wider than 100 meters in winter, a distance easily traversed by most other carnivores. Grizzly bears can easily cross a 100-meter clear-cut and fishers don't seem to mind roads but our native cutthroat trout need large roadless areas to stop their rapid decline towards extinction, and require four habitat types over their lifetime. We need to study interaction between species; between carnivores and prey; herbivores and plants and the effect of carnivores on herbivores and therefore on plants. We need to consider the succession of different species in an area over time; that floods and drought give new species a niche. We need to consider the continental migration of birds and butterflies, and the long range-dispersal of individuals over time and generations. We need to include ecosystem processes such flood, fire, drought, water cycles as well as nutrient cycling, that are an integral part of the way the ecosystem is balanced; all part of larger patterns and rhythms. Focusing on saving an individual species, plant or animal, simply will not work over time. The fundamental insight of a hundred years of ecological study is that everything is connected.

The reserve design of the Y2Y addresses all these needs as best we know how at this time Vast amounts of scientific literature from many different fields boil down to: bigger is better; connected is critical; isolation and fragmentation result in extinction. The basics of large-scale reserve design include three major components. The first is setting aside strictly protected cores of wilderness with key biological significance for species sensitive to human disturbance. These cores are surrounded by buffer zones, or multiple use zones that protect the core but can sustain some human activities compatible with wildlife. The cores and their surrounding buffer regions are connected by corridors to allow for migration patterns and the natural movement of individuals among the reserves. Reserve design must also consider changes over time; development, population growth, major range shifts, climate change and future evolution.

With respect to our human needs, the goal is to have vibrant human communities imbedded in vibrant healthy ecosystems. The method is "People working together to maintain and restore the unique natural heritage of the Yellowstone to Yukon region." The Y2Y philosophy is to encourage local planning and control, as these are the people most knowledgeable and committed to their area. The initiative works with chambers of commerce and community leaders to encourage them to think in terms of ecosystem management rather than piecemeal management. They provide a continental perspective for needs of wide ranging wildlife, and demonstrate how local conservation efforts strengthen the whole web of life, with benefits to all. Roy Rasker of the Northwest Office of the Sonoran Institute did an economic analysis of the 20 counties around Yellowstone National Park. Contrary to popular belief, the results indicated that it is jobs AND the environment. Those counties that set aside land for enjoyment and preservation did significantly better economically that those that didn't, or those that focused on the traditional extractive industries. Having and preserving wilderness is a significant economic asset and managed well can provide for the needs of both wildlife and people, a fact that is increasingly understood and acted upon by communities up and down the Y2Y region. Maintaining a high environmental quality gives a long-term competitive advantage. Another area of potential conflict between human and wildlife needs is private land development. Almost half of the endangered species list exists almost entirely on private lands. However in much of the west and our area in particular, large tracts of farmland vulnerable to development are a primary threat to our region's ecosystem and function. From 1990 to 2000 Teton County, Idaho was the fastest growing county in the area, at 74% growth. One problem is that we want the same land that wildlife needs - we like to build along riparian habitat and on the fringes of public land. The good news here is that many private landowners are looking for ways to keep their land healthy, and techniques pioneered so well by The Nature Conservancy such as conservation easements remain an important tool in preserving specific areas of land. And we still have an opportunity to craft an economic and development strategy compatible with protection of wildlife, one that capitalizes on our great natural resources without destroying them. Local conservationists and biologists are in the best position to determine local priorities for conservation and recovery, but we can contribute even more. Each regional planning group can think in terms of responsibility to all the land, not only their particular region or state. In the end, only by coordination of planning in the entire continental network is the full return of land vitality is achievable. In this picture of a larger system, every person counts. Some apparently small and local actions can have far reaching effects. There are places along the antelope migration route where access to Jackson Hole boils down to a single pathway which every antelope must walk two times a year. The actions of a single homeowner can make a crucial impact. In other places it is not the house itself but the human activities that are a problem, such as free-ranging dogs which could be contained. Many people simply don't realize the impacts of their actions and would be glad to take wildlife needs into consideration given the right information and the larger picture. If habitat fragmentation is a major cause of the current extinctions, then we are making significant positive strides to combat it. Along the Y2Y millions of additional acres have already been protected. In 2000 a Maine Wildlands Network plan was completed for a ten millions acre remnant of Thoreau's Maine Woods, the largest block of undeveloped land east of the Mississippi. In the same year the Sky Islands Wildlands Natures Conservation Plan was released, designed to protect the unique mountaintop "islands" throughout New Mexico and Arizona. And there is increasing acceptance of an even larger vision- a vision of interconnected webs of wildlife habitat interwoven among human populations throughout the continent, an interweaving that meets the needs of both humans and wildlife.

According to biologist Paul Paquet, of the World Wildlife Fund, "What we have in the Rocky Mountains is rare - an almost complete representation of all native large mammals that roamed the great hills before Europeans arrived. From the perspective of the great mountain ecosystems of the world, it's the last of the last... It is the last great refuge for many species, a Noah's arc of functioning populations still left of many species. If we can't save them here we can't save them anywhere." and there will be nothing left to repopulate other areas when the time comes that we realize what we have lost.

For information on the Y2Y or any of the topics presented in here, contact www.y2y.net.