WOOD RIVER, Neb. — To the human eye, the shallow, muddy Platte River surrounded by razed cornfields and brown pastureland is, at best, austere.
To the half-million sandhill cranes that land along an 80-mile stretch of the river each spring, it's an open space to roost that doesn't offer hiding places for predators. The birds also see plenty of places to feed on scattered corn and insect-rich cow dung.
"They build their reserves here; that's why they hang out here for so long," explained Tim Tunnell, grassland manager for the Nature Conservancy, which is in partnership with the Nebraska Game and Parks Commission to promote restoration and conservation of the Platte-area grasslands so important to the cranes' existence.
The 3- to 4-foot-tall cranes pack on as much as 20% of their body weight by gorging on corn left in the fields from the previous fall's harvest. They also use their beaks to flip over cow patties to dine on insects and grubs found underneath them.
"Just like they turned over buffalo patties before cattle were here," said Keanna Leonard, education director of the National Audubon Society's Rowe Sanctuary near Gibbon.
The light gray, heron-like birds need the extra calories to continue migrating from their winter grounds in the southern United States and Mexico to northern Alaska, Canada and Siberia, where they spend the summer. Once they reach those northern climes, they will nest and hatch their young before venturing back south and beginning the migratory cycle again.
But it's their three- to four-week layover along the river from Lexington to just west of Grand Island that has people from around the world pouring into the Cornhusker state from mid-March through April. Some estimates have about 60,000 people showing up, some of them simply pulling over on the shoulder of Interstate 80 to watch the cranes fly over or share corn. Others set up predawn bird-watching tours in various unheated blinds that are often a half-mile's hike from the nearest road.
There, they wait with binoculars for the birds to take off, careful not to make a sound for fear of spooking them.
"It's fascinating to see," said Eric Hoff, a seasonal employee for the conservancy who leads sightseeing tours. "I can see why people would wonder what it is about the heart of Nebraska that attracts them."
The cranes' high-pitched squawks are deafening. Many perform a curious dance, jumping and flapping their wings -- intent on attracting the attention of other birds.
The dance is indicative of a larger one played out as man and crane seek to thrive along the river. In some respects, the two species are good for one another.
The cranes reap the benefits from the advent of agriculture along the river, giving them adequate and easily accessible food. They also get help from organizations like the Crane Trust, the Nature Conservancy, Rowe Sanctuary and others, which work to keep the area attractive to cranes and other wildlife. That includes tilling the land around the river to prevent trees and other vegetation from growing, which would keep the cranes away.
The cranes, in turn, spark a surge of tourism for central Nebraska that brings people from as far as China and Madagascar and helps pump up the area's economy.
But there are hitches in the dance that sometimes find humans and birds stepping on each other's toes.
Tunnell, who works with private landowners along the Platte to conserve land for the cranes, conceded that advances in agriculture mean more grain is making it into harvest bins than before.
"We have to do what makes sense for farmers and other landowners here -- in most cases, economically," he said. "We can't really say, 'You need to alter your harvest techniques to leave more corn on the ground.' They'd just be leaving money on the ground."
Some farmers also find the influx of people more disruptive than the cranes. They complain that their tractors are obstructed by vehicles pulled over on back roads to watch the cranes.
Some people want to build recreational houses along the river, despite pleas to keep the area open for cranes. Others are angry that sandhill cranes are protected from being hunted in Nebraska, but not in other states along their migratory path.
Then there's the concern that the cranes could bring a deadly strain of bird flu to the area after congregating up north with other waterfowl populations known to carry it.
"All of the game agencies are watching that very closely," Tunnell said. "That's one of the reasons we're trying to get these roosting sites spread out a little bit along the Platte. If there is an outbreak of bird flu in one part of the river, the whole Earth population isn't affected, because they're spread out."