On the morning of March 14 this year, 40,000 sandhill cranes were waking from their roost, wading on sandbars in the Platte River in central Nebraska, resting on their spring migration. I shared this sight with fellow local bird watchers Fran and Ranjit, and with Maureen from Lincoln, Neb, while we stood in a blind at the Rowe Audubon Sanctuary along the Platte River. Last year, the sanctuary had 15,000 visitors from all 50 states and more than 20 foreign countries. The sight of 40,000 birds is staggering, so I wish to share this exciting experience with you.
The sandhill crane, an uncommon visitor to Chautauqua County during migration but the most common crane in the world, is an attractive bird with a 6-foot wing span, 6- to 12-pound weight, and 3-foot height. The forehead skin of the mature crane is a featherless bright scarlet color. A white cheek patch and black wing tips, evident when flying, are reliable field marks to identify this crane. All cranes fly with legs extended behind and necks straight out in front, unlike similar looking herons which fold their long necks back in an ''S'' during flight. As an omnivore, cranes eat plant roots and seeds as well as animals such as snakes, insects, and worms.
Between early March and mid-April, 500,000 sandhill cranes migrate through central Nebraska from wintering grounds in New Mexico and Texas, to nesting sites in Wyoming, Wisconsin, northern Canada, Alaska and Siberia. Florida supports a small non-migrating crane population. Crane fossil wing bones discovered in Nebraska, estimated to be 9 million years old, reveal the long history of cranes living in Nebraska. Today, sandhill cranes stop for three to four weeks along the Platte River to feed on waste corn and grain in nearby fields to fatten up before continuing north. Roosting at night in the shallow water of the Platte River provides a safe haven, allowing the cranes to hear approaching predators, like coyotes, that might enter the river.
A sandhill crane performs a dancing ritual while the flock roosts in the Platte River, near Kearney, Neb., this spring.
Photo by Robert M. Ungerer
Sandhill crane behavior often resembles human actions. Mating for life appears to be consistent, although Keanna Leonard, a nature educator at the Rowe Sanctuary and observer of sandhill cranes for more than 20 years, tells children ''cranes marry, may have affairs and even divorce.'' The mother and father crane share incubation of two eggs, defend the nest and migrate with their young as a family until the next breeding season. Cranes around the world perform a unique social ritual called ''dancing,'' jumping up and down with wings outstretched. Crane observers attribute this behavior as a courtship dance to impress a girlfriend, to solidify a pair bond like a wedding dance, and to play. We observed this frequently from our blind on the river. Cranes use nine different calls to communicate with each other. On this trip, we were privileged and fortunate to hear to Paul Johnsgard, an 80-year-old University of Nebraska professor and author of five books about cranes, lecture on sandhill cranes. In one of his books, ''Crane Music,'' which I purchased and received his autograph, he explained a special unison call made between a pair bond couple to cement a relationship or after the male evicted an intruder. While facing each other, one calls softly; the other responds loudly, as if to say, ''I like you and thank you for what you have done to chase away the intruder.'' The unison call may stimulate synchronization of female ovarian readiness and the male desire to mate. It is remarkable that crane pairs and their young can find each by calling when separated on the river at night or in a corn field during the day.
Throughout history man has revered cranes for their large size, human-like appearance, gregariousness and daytime momentous migratory flights. Japanese and Chinese civilizations used cranes in art as a symbol of long life, happiness, steadfastness and love.
Information about observing cranes near Kearney, Neb., is available online at www.rowesanctuary.org. One can watch live cranes on the river this spring just after sunrise and before sunset, central time by Googling ''rowe sanctuary crane cam.''