For the Birds Radio Program: Cranes of the Platte
Today Laura Erickson talks about a national treasure 4:08
Beginning around Valentine’s Day every year for the past million or so years, Sandhill Cranes have gathered along the Platte River valley to feed on the rich floodplain. They trickle in slowly in February, but as March arrives, they arrive en masse, 80 percent of the world’s population of Lesser Sandhill Cranes descend upon this area in one short month. Some days during warm fronts, you can look up any time and see hundreds migrating in high overhead. During historical times, literally millions of birds gathered here, and even today the cranes that come here total half a million birds. Each individual remains in the area for about 28 days, and so by mid-March when they peak, hundreds of thousands can easily be seen in a day. They spend their days pigging out and their nights sleeping on the river. The Platte is wide and shallow–only about 6: deep—but that’s deep enough to keep hungry coyotes at bay, so the cranes can sleep in relative safety.
All the birds must fatten up in preparation for the last long leg of their migration, and the females need to take in enough extra nutrients to produce two healthy eggs once they reach their destination. Each bird puts on between half a pound and a full pound of fat—a substantial amount to add to a total body weight of ony about 7 pounds. The smallest migrants, the Lesser Sandhill Cranes, are headed for northernmost Canada, Alaska, and even Siberia, and will do little more stopping before they get there, so this fat buildup is essential for their survival.
The 50-mile stretch between Grand Island and Kearney is especially rich in cranes—that’s where the river widens with the least amount of human interference. Denver takes its water from the Platte, Nebraska farmers suck out its waters for irrigation, and the rich wetlands of the river valley have been drained for agriculture and settlement. The natural vegetation and wetland critters that cranes once depended upon have been edged out by corn, but cranes can eat that, too. At night, they gather on the river, standing all night in the shallow water in tight groups. In moonlight we see irregular islands that become transformed in the pink light of dawn into islands of cranes.
As the month progresses ad birds get plumper, their hormones kick in more and more and they develop a serious interest in romance, which in the crane world is demonstrated through dance. Crane dancing serves not only to cement pair bonds but also to synchronize each pair’s reproductive cycles. If females don’t dance, they simply can’t ovulate, and if males don’t dance, they can’t produce sperm.
These birds take their dining and dancing seriously. In early March, they wake up, talk a bit, and fly off to breakfast, not thinking about dancing until late afternoon, but by the end of the month just looking into one another’s eyes as the sun peeks out is enough to get their toes a tapping and their wings a flapping.
Dancing cranes are about as rich a spectacle as the world provides. In Japan, these birds are considered a natural treasure, symbolizing longevity, fidelity, and happiness, but oddly, here in America cranes haven’t really caught on as a symbol of anything. Most people haven’t even heard of the Sandhill Crane. Sadly and oddly, the most famous of all cranes in this country isn’t a bird. It isn’t even a piece of heavy machinery, but it does share a bald head with its fellow cranes, this most well-known crane of all here—Frasier Crane. Cheers to you.