The Central Valley of California is known for its sweeping farmlands, where a vast portion of our nation's food is grown. But among birders, it is also known as a major freeway for migratory birds. During winter months, the miles of fields, and the few remaining wetlands, fill with hundreds of bird species — from waterfowl to shorebirds — including one spectacular and ancient bird, the sandhill crane.
The sandhill crane is a prehistoric species; one fossil dates back to 2.5 million years ago, making the species older than many of today's living species of birds. They reach a height of about four feet, and have a seven-foot wingspan. They're also known for their courtship dances, in which two birds face each other and leap into the air with their wings outspread. They bow, call, and toss bits of grass and weeds into the air as part of the courtship performance as well.
Crucial to the birds' survival — and just as ancient — is the Pacific Flyway, the migratory route that many bird species follow from summer homes in Siberia, Canada and Alaska down to southern regions of North America or even farther south. California's Central Valley lies in the heart of the flyway, acting as a vital rest stop and wintering ground for many of these species.
"California’s wetlands once supported 40 to 80 million waterfowl each winter. As more people moved into California, 95 percent of the wetlands were converted to farmland, cities and other uses," according to Nature.org.
The Central Valley is one of the places where the conversion of wetlands to farmland has had devastating effects on migratory birds, especially the sandhill crane.
"Greater sandhill cranes were once common breeders throughout the intermountain West, wintering primarily in the Central Valley of California. However their populations declined drastically as a result of unregulated hunting and habitat loss during settlement of the region," Audubon writes. "They became extinct as a breeder in Washington by 1941, when there were only an estimated 150-200 pairs remaining in Oregon. In California, the breeding population was reduced to fewer than five pairs by the 1940s."
The good news is that with conservation efforts, the population of greater sandhill cranes has increased, and in 2000 there were an estimated 465 pairs breeding in California. A significant reason for this stabilization and tentative rebounding of the species is the work Audubon and other conservation groups have done with ranchers and farmers in making private land a safe place for the wintering birds.
The cranes are especially sensitive to habitat loss because they roost at night in shallow wetlands but feed by day in agricultural fields, and typically travel no farther than about two miles to get from one to the other. So appropriate roosting and feeding grounds need to be found fairly close together. While progress has been slow, conservationists and farmers have made some headway in forming a network of managed land where both greater and lesser sandhill cranes can feed and roost.
"Since 2008, Audubon helped secure two conservation easements in northeastern California to protect ranches with irrigated pastures that support greater sandhill cranes," Audubon states. "As part of the Migratory Bird Conservation Partnership, Audubon has an opportunity to take specific action targeting sandhill crane conservation in the valley. Working with these partners, Audubon is increasing the amount of farmland in the Central Valley that is managed specifically for sandhill cranes."
Consumnes River Preserve and Woodbridge Ecological Reserve are two examples of reserves settled in among farmland, where cranes and myriad other migratory birds can be viewed.
The conversion of wetlands into farmlands is one issue for the cranes, but not the only one. Because they are a wetland bird, they are sensitive to water shortages and drought. Climate change, mismanagement of water resources, and habitat loss are all pieces of the big picture affecting this species. But the fact is, birds now need farmland to survive.
"Over 200 bird species in California depend on agricultural habitats for at least part of their annual life cycle... Millions of waterbirds rest and feed in wetlands provided by winter flooded rice fields in the Sacramento Valley and it's estimated that 70 percent of the food needed to support the more than 5 million waterfowl wintering in the Central Valley every year is produced by private agricultural land," Audubon says.
If you'd like to view the California populations of cranes, you can look up tour opportunities with the California Department of Fish and Wildlife. And you may also want to schedule your visit around the annual Sandhill Crane Festival held in Lodi, Calif.
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