Wednesday, March 25, 2015

The Sandhill Cranes of Nebraska

Some places have a signature animal species that defines a particular natural environment.  For me, they include the alligators of the Okefenokee, the wolves of Isle Royale, and the Kirtland's Warbler of the Au Sable Plains.  Ever since youthful trips across the Great Plains in the spring, I have also associated the Sandhill Cranes with the Platte River of Nebraska.  Recently, I had the chance to learn more about this remarkable bird and its relationship to this open sky place.

The Migration of Sandhill Cranes is one of the great animal spectaculars of North America, rivaling the annual movement of caribou.  While some sandhill cranes winter in Florida and Cuba, most spend the winter in Texas and Mexico and travel north to the Canadian taiga, the arctic tundra, and even across the Bering Strait into Siberia. But as the sandhill cranes fly northward, they funnel through an 80 mile stretch of the Platte River in Nebraska where they rest and refuel in the cornfields and early spring wetlands along this iconic stream.

"A mile wide and an inch deep" is the classic description of the Platte River, which carries sediment from the eastern slope of the Rockies, drops it in a braided stream on the plains, and then slowly flows into the Missouri River.  It was a source of sustenance for the Souix and the pathway west for the pioneers.  It now supports a vigorous, irrigated agricultural landscape.  The sandhill cranes have been there all along.

The productive soil of the prairie has provided food, and the river has provided protection.  During the day, the cranes glean corn from last year's fields, and add protein from insects, reptiles, and even small mammals in the wetlands and preserved grasslands.  Each night, the cranes return to the Platte to rest on sandbars or stand in the shallow waters, relatively safe from predators. The mass movement of thousands of birds at dusk, and again at dawn, is an awe-producing sight for which I--and many other birders--are willing to huddle in cold blinds to witness.

An Ancient Bird is the sandhill crane.  Fossil records show that the direct ancestor of this tall creature was present in Nebraska nine million years ago, back when the continent rested much closer to the equator.  Over time, as the continent moved and climates and habitats changed, the sandhill crane adapted and evolved.  We tend to think of a large, flocking species as the embodiment of a particular ecosystem, and of course it is, but the fact that the sandhill crane has persisted through millions of years powerfully reminds me of the resilience of nature.

Today, the sandhill crane has adapted to the presence of humans and industrialized agriculture.  The presence of cornfields along the Platte River has provided an important food source for the migrating cranes, probably supplanting tubers and other plants that used to be found in the now-diminished wetlands along the Platte.  The Sioux hunted sandhill cranes, as do Texans today, and the bird must now contend with the noise of the omni-present trucks of I-80,  power lines, and other human interferences.  Even though we snuck into blinds, and kept our distance as we stopped along country roads, the cranes have also adapted to the thousands of bird-watchers who travel to Nebraska each spring.

This is not to say that humans can be oblivious to their impact on wildlife.  Just witness the near demise of whooping cranes, the similar, bigger, all-white representative of North American cranes.  The loss of their winter coastal wetlands and vigorous hunting almost led to their extinction.  There are only a few hundred of these magnificent birds now living in the wild.  Only through the intervention of governmental entities like the US Fish and Wildlife Service and groups like the International Crane Foundation, have the whooping cranes survived.

A Middle Ground needs to be found between ignorance, or antipathy, to nature and the segregation of humanity and the wild.  Standing among the tall cottonwoods on the banks of the Platte, it easy to imagine a pre-civilization wilderness riparian forest.  However, our imagination would be wrong, as the trees have only grown up after the suppression of fires and the regulation of the floods of the river.  Of course it is technically feasible to restore the Platte River ecosystem by returning more water flow to the stream, pushing agriculture out of the valley, and reinvigorating the prairie and marshes.  Practically, this is not likely, given the political demands on water in the west, the economic prowess of American farming, and the two centuries of modern civilization in Nebraska.

So to preserve the habitat of migrating cranes and the other species that depend on the Platte, we have applied human ingenuity and societal resources.  The Nature Conservancy has used its traditional land protection skills to strategically acquire farms and restore prairies adjacent to the River, the Audobon Society has protected important migratory sites, and state and federal governmental agencies adopt and enforce wildlife regulations.  These actions have helped the whooping cranes survive, and the sandhill cranes to thrive.

Whole System Conservation is the term now applied to much of the work of The Nature Conservancy, and its goal is to understand and then manage the large scale functioning of the environment.  It is underway in the Great Lakes, the Mississippi River, and throughout the globe. This work requires not only land preservation, but also important attention to the policies that govern human economy and society.  We are not separate from nature, and we must be stewards of our natural systems so that they benefit both the natural inhabitants as well the human ones.  We all depend on nature.

In the Platte River ecosystem, not only do sandhill cranes and other species depend on a healthy environment, but so too does agriculture.  A first step is to acquire easements on agriculture land that compensate farmers for leaving some of their land out of production some of the time.  Thus, more habitat can be protected.  But the key issue in the West (and perhaps everywhere) is water.  Three states and many agencies and organizations have come together to manage water flows and use in the Platte River system.  The goals are many, the compromises not always easy, and the potential for success great.  Science provides new solutions, and The Nature Conservancy has teamed up agribusiness to use technology to allow for pinpoint irrigation management; this helps save energy costs for farmers and water for the environment.

Too often we choose to ignore nature, filled with hubris in thinking that we can pursue our own needs without regard to the places which we inhabit.  Or we are unwise in the exercise of our abilities and we use our knowledge without a value system that includes nature.  But the Platte River and sandhill cranes are showing us that putting nature foremost is not only possible, but beneficial to both animals and humans.  Not only have we achieved a balance between humans and the environment, but sandhill cranes benefit from agriculture, depending on leftover corn to fuel their migration.  And the local economy benefits from the $10 million impact from the many humans who come to Nebraska to view the cranes.

Throughout the world there are 15 species of cranes, and most are held in special esteem by the various cultures which have evolved along with these most special creatures.  Sandhill cranes have long been celebrated by Native American residents of the Great Plains, and now we are building a tourism, economic, and environmental culture that values both the cranes and the Platte River ecosystem upon which they depend.


 To visit:  Sandhill cranes migrate through the Platte River Valley between late February and early April, thought the time of peak migration can vary by many days.  The Nature Conservancy, Audubon Society, and others run tours.
Kearney, Nebraska offers an annual festival and support for viewing the cranes.

To learn more about the work of The Nature Conservancy in Nebraska and elsewhere visit www.nature.org/nebraska

The best book I have ever read about cranes is Peter Matthiessen's Birds of Heaven: Travels with Cranes which documents his worldwide journey to learn more about the importance of these very special animals.

Thank you to Anna Owens for the photographs, and the company.

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