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Cranes at the Zoo

white-naped crane
Red-crowned crane at the National Zoo. (Jessie Cohen, NZP)

Given a balanced diet, ample space, and diligent care, most crane species breed well in zoos. The Smithsonian’s National Zoo breeds white-naped cranes at its Conservation and Research Center (CRC) in Front Royal, Virginia. The Zoo carefully coordinates its breeding efforts with other zoos in the North American Species Survival Plan for white-naped cranes. CRC staff usually aim to breed one or two pairs a year. When necessary, artificial insemination (AI) is used to ensure that optimal genetic pairings bear fruit. “If we have a new pairing, we see if they breed on their own,” says Scott Derrickson, CRC’s deputy associate director for conservation and science. “We usually try to give young pairs one or two years to produce on their own.” During this time, through unison calling and ritualized dances, pairs may cement their bond and begin breeding. “Otherwise,” says Derrickson, “we go to AI.”

Fifteen white-naped cranes have hatched at CRC since 1981, five of these since 2002. Red-crowned cranes (G. japonensis) are bred there as well. Whenever possible, young CRC cranes are raised by their parents before being sent to facilities that request them. Naturally imprinted to other cranes, they will be attracted to others of their own species and are less likely to exhibit extremely aggressive behavior toward their mates, which has sometimes been a problem with cranes imprinted to humans.

wattled cranes
Wattled crane chick and adult at the National Zoo. (Jessie Cohen, NZP)

In March 2007, the Zoo celebrated a surprise hatching of its first-ever wattled crane (Bugeranus carunculatus) chick. Bird House biologist Sara Hallager says it was not only a Zoo first but also the first wattled crane hatched in four years in any North American zoo. Zoo cranes face a certain logistical challenge when it comes to mating: After male and female display to each other and the female takes on an inviting posture, her mate must flap up to land atop her back so they mate, an event that takes about five seconds to complete. The birds, which are kept outdoors, are pinioned—the “wrist” of one wing is clipped when the birds are very young so they do not fly off. This often makes mating difficult. “It’s the same problem present in flamingos and other long-legged wading birds where copulation takes place off the ground,” says Hallager. “When we got this fertile egg, at first we thought it was a fluke.” But a crane chick hatched out of the egg in 2007. “We’ll have to see if it will work again this year,” Hallager says. After growing up under the tutelage of its parents for the better part of the year, the juvenile will soon be sent to the Saint Louis Zoo as part of the wattled crane Species Survival Plan.

The Zoo exhibits three other crane species: the world’s tallest flying bird, the six-foot-tall sarus crane (Grus antigone), the red-crowned crane—both from Asia—and the blue crane (Anthropoides paradiseus), a grassland species that is the national bird of South Africa.

—Howard Youth