| ENVIRONMENT |
Considered one of the last great animal migrations on Earth, the Sandhill cranes stop over in the Central Platte River Valley is unprecedented in scope and size. It’s not unusual for the sky to go dark as thousands of migrating birds fill the air blocking out the sun.
Article & Photography by: Hawk Buckman
Published March 08, 2020
Each year over 600,000 Sandhill cranes migrate through an 80 mile wide stretch of Nebraska on the Platte River following a corridor they have used for over 10,000 years called the central flyway – a path utilized by cranes, geese, ducks, and shorebirds.
The Central Flyway is a bird migration route that’s shaped much like an hourglass that follows the Great Plains in the United States and Canada. The endpoints of the flyway include central Canada and the region surrounding the Gulf of Mexico. The migration route narrows considerably in the Platte River and Missouri River valleys of central and eastern Nebraska, which accounts for the high number of bird species found here including the Sandhill crane.
Stretching from as far south as Mexico to as far north as Siberia, the central flyway is cinched into an 80-mile-wide stretch in the central and western half of Nebraska. Ruffly 80 percent of migrating sandhill cranes congregate in parts of this cinch, where they reach their greatest density.
The flyway is utilized by the birds because there are no mountains or large hills blocking the flyway over its entire length. Over the past 10,000 years good sources of water, food, and the cover has existed over its entire length but the future of the Sandhill crane is at risk due to loss of habitat and pollution. Only 10 percent of the habitat is now suitable for sandhill cranes according to Bill Taddicken, director of the Iain Nicolson Audubon Center at Rowe Sanctuary in Gibbon.
Agricultural use and urban development have stunted prairie grasslands along the North Platte River threatening food resources. In recent years the sandhill crane migration has begun to take a turn toward the East due to a depleting ecosystem which has put a strain on the birds. Each year fewer birds reach their destination as it takes longer to arrive at the coastlines of North America.
With every passing year migrating “survival groups” of birds have begun to extend to the western half of Nebraska reaching as far west as Scotts Bluff, Morrill, Sioux, and Banner counties, areas of Nebraska not normally visited by the migrating birds.
Each day cranes flock to farmer’s fields to feast on corn left on the ground from the year’s harvest where they get 95 percent of their food. The other 5 percent is taken from the North Platte River, or another body of water. The food is high energy and does assist the birds in putting on weight for their long journey but it’s not healthy for them. The birds need a balanced diet to make the long journey south in the winter and north in the summer.
Biologists caution that further habitat loss poses a risk to the birds. The central flyway is shrinking and continues to move eastward as well as westward. With each passing year, the birds are arriving earlier. These stressors exhaust the birds making it difficult to fly hundreds of miles each day during their migration.
It’s unclear how climate change is having a direct effect on the birds. What is clear is that the North Platte River is polluted. Agricultural runoff consisting of heavy metals, ammonia, and arsenic has polluted the river for years. Nebraska’s waterways are the sixth-worst in the nation for toxic pollution. Most of the contamination is because of nitrates.
Nebraska industrial facilities dumped 10.5 million pounds of toxic chemicals into the state’s rivers and streams in 2012. In western Nebraska, the majority of toxins were introduced to rivers and streams via spills from agriculture processing plants, street runoff, and windblown coal dust.
In a report by the nonprofit Environment America Research and Policy Center in Washington, D.C., using data reported to the Environmental Protection Agency’s Toxics Release Inventory, Nebraska industrial facilities dumped 10.5 million pounds of toxic chemicals into the state’s rivers and streams in 2012. In western Nebraska, the majority of toxins were introduced to rivers and streams via spills at sugar beet processing plants and windblown coal dust.
The toxic chemicals dumped in Nebraska rivers and streams include chromium and chromium compounds, which cause cancer, and developmental toxins, such as lead and lead compounds. These heavy metals have a direct and detrimental impact on the wildlife along the North Platte River- poisoning plants, fish, amphibians, and reptiles- all food sources for migrating cranes.
The North Platte River is a unique river ecosystem that has drawn the birds to the area for over 10,000 years. Agriculture and industrial pollutants are beginning to change the environment and jeopardize the future of the sandhill cranes’ migratory path through the central flyway.
||| THE NORTH PLATTE RIVER IS FAILING
Centuries of cycling drought, fire, and wind have carved the Great Plains. The birds once depended on the plains to sustain themselves in their migration.
Today the Platte River is their stronghold against starvation in their long journey. The condition of the Platte continues to deteriorate due to pollution and loss of habituation on the plains forcing the birds to scatter out.
The loss of the habitat along the Platte would be devastating to the ecosystem. There’s nothing of comparable size and quality to replace it and nowhere for the birds to go.
Seeing a sandhill crane in WyoBraska is clear evidence that the Platte River and the Great Plains are changing. The birds are being forced to migrate east and west of the central flyway in search of food and mates. Though beautiful to behold and hear the cranes are trying to tell us a story. It’s the story of the end of their long journey through the plains for thousands of years. It’s the story of human influence and the destruction of a unique ecosystem that has sustained them for millennia.