Whooping Crane

Whooping Cranes
By Connie A. Wood
Fall 97

The Whooping Crane, Grus americana, is a white crane with red cheek patches and black wing tips. It grows to 5-5 ½ feet tall which distinguishes it as the tallest bird in North America. The wingspan of adult whooping cranes average 7 feet. The whooping crane gets it name from the loud call it makes that can be heard miles away.

The number of whooping cranes has fluctuated since counts were reported in1865. At that time there were between 1,200 and 1,400 whoopers. Human activities such as farming, hunting and egg collection reduced the bird’s number and habitiat. In the 1940’s there were only about 15 whooping cranes alive. The U.S. Wildlife officials counted 149 whooping cranes in November of 1995. In Feburary of 1996 an aerial survey showed a count of 156 whooping cranes at Aransas National Wildlife Refuge.

The estimate of world population of whooping crane is 320 with 25 in captivity and two other wild populations. The three wild populations of whooping crane are found at Aransas National Wildlife Refuge in Texas, Gray’s Lake National Wildlife Refuge in Idaho and Kissimmee Prairie in Flordia.

One population of whooping cranes arrives in April to their breeding area in Wood Buffalo National Park, Alberta, Canada. They spend the warmer months of April through September there. At that time they breed and produce offspring. During breeding, they perform a courtship dance that includes loud calls, jumping and flapping their wings to attract their mates. They mate for life. The female produces two eggs. Both adults incubate the egg for a month. The chicks can swim immediately after they hatch . They can fly in 80-90 days. The lifespan of a whooping crane is 24 years in the wild. At the end of September they start a 4,000 km flight south to Aransas National Wildlife Refuge near Port Aransas, Texas. They can fly up to 10 hours a day by gliding with wind currents. About 30% of the whooping cranes die during mirgration. The main cause of death of the whooping crane is collision with power lines during migration. Development of agricultural, recreational and industrial sites along the migrational and wintering sites have also caused the numbers of whooping cranes to decrease. Habitat loss is a danger to the whooping cranes. They use several habitiats – breeding grounds, migration stopping sites and wintering grounds. Major areas of concern are conversion of wetlands and grasslands, changes in agricultural land use, erosion, livestock grazing in wetland areas, increased use of pesticides and fertilizers, water diversion, urban expansion, deforestation, afforestation, marsh and shoreline erosion, pollution and oil development. The migration route, nesting locations and wintering routes are learned behaviors. Young birds learn the route on the first migration.

Whooping cranes eat shellfish, snakes, acorns, small fish and wild fruit while they winter in Texas. They eat larval insects, snails, leeches, frogs, minnows, rodents, and berries while in Canada. During migration they may scavenge such things as dead ducks or marsh birds. Also they eat aquatic animals, roots, plants and waste grain.

One management concern of whooping cranes in the Aransas National Wildlife Refuge is the danger of destroying the entire population there if an oilspill occurs. Their wintering grounds are next to an intercoastal waterway. Since 1967, surplus eggs have been hatched and reared on captivity.

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