Tom Stehn 512-286-3559
September 24, 1998 Hans Stuart 505-248-6911
FALL WHOOPING CRANE MIGRATION BEGINS SOON;
NUMBERS APPROACH RECORD HIGH LEVELS
One of nature's most spectacular and closely watched events, the migration of the endangered whooping crane, will unfold across America's heartland during the next several weeks. Almost 200 whooping cranes will trek across the Great Plains in October, migrating from Wood Buffalo National Park in Canada's Northwest Territories to the Aransas National Wildlife Refuge on the Texas Gulf Coast.
The story of the whooper's recovery from a nadir of 15 birds in the winter of 1941-42 has been celebrated across the world. Progress continues this year with near record numbers of cranes reported in the wild and in captivity. More than 190 cranes in the Aransas-Wood Buffalo flock are expected to arrive in Texas this fall, including 24 chicks that survived through mid-August.
Biologists counted a record 49 pairs nesting at Wood Buffalo National Park in late May. Last fall, 182 birds including 30 young, made the fall migration.
The only other whooping cranes in the world include four in a Rocky Mountain flock, 57 in a non-migratory flock being established in central Florida, and 133 in captivity for a total population of about 375.
The 2,500-mile journey will take the Aransas-Wood Buffalo cranes through Alberta and Saskatchewan, Canada, and the Midwestern States of North and South Dakota, Montana, Nebraska, Kansas, Oklahoma, and Texas. Southward migration requires up to 50 days including a 2-day flight from the breeding range to southern Saskatchewan grain fields where birds remain 1 to 5 weeks, followed by a rapid 1-2 week trip across U.S. prairie states.
Migration by subadults begins in mid-September; family groups and paired adults usually start in early October. Migration begins with northerly winds, good visibility, and increasing barometric pressure. The average date when the first whooping cranes pass through the Dakotas, Montana, Nebraska, and Kansas is October 10 to 15. Migration through Oklahoma and Texas is about October 15 to 20. The first whooping crane arrival at Aransas NWR occurs on average about October 16.
In the Rocky Mountains, three of four whoopers began their migration south from Yellowstone National Park this week to the Rio Grande Valley of central New Mexico, and are currently in southeastern Idaho.
- more - Two of the cranes are the only remaining survivors of a foster parent experiment where whooping crane eggs were placed in sandhill nests, with the adult sandhill cranes teaching the whoopers to migrate. The other two were raised in captivity by researcher Kent Clegg last year and taught a migration route between his ranch in southeastern Idaho and the Bosque del Apache National Wildlife Refuge.
"This experiment marked the first time whooping cranes had been taught to follow an ultralight aircraft," said Tom Stehn, Whooping Crane Recovery Coordinator for the U.S. Fish and Wildlife Service. "The experiment was a success because it showed that the birds could be taught to follow an ultralight and that they could quickly learn to survive with wild sandhill cranes. The two birds that survived the winter migrated back north on their own, proving that they didn't have to be led back north."
Whooping cranes migrate during the day, making regular stops to feed and rest away from human activity. They travel as singles, pairs, family groups, or flocks of 4 to 5, sometimes joining with sandhill cranes for part of the migration. The most common flight grouping is a V-formation at an altitude of 1,800 to 4,500 feet above the ground. Their energy-efficient flight results from sequences of spiraling upward in thermal updrafts followed by long, declining glides. They may travel up to 440 miles in 9 to 10 hours under ideal conditions with a tail wind. Average speed of travel is 250 miles in 7 to 8 hours.
Wildlife officials ask anyone seeing a whooping crane this fall to report the time, place, and other details of the sighting to local wildlife officials. Adult whooping cranes are white with black wingtips and a red forehead. In flight, the bird's long neck is held straight forward, and its long black legs extend beyond the tail. The adult's wingspan may be more than 7 feet, and when standing, some males are as tall as 5 feet. Juveniles have white and rusty brown body feathers and black wingtips.
Several birds may be misidentified as whooping cranes. Sandhill cranes are primarily gray (but sometimes appear whitish in bright sunlight) with dark gray wing feathers. Sandhills are noticeable smaller than whooping cranes when they are seen standing together. Snow geese are white with black wing tips but are much smaller than whooping cranes, with short legs that do not extend beyond their tail when flying. Snow geese fly with rapid wing beats and typically occur in large flocks. White pelicans are large white birds with black on the wings, but do not have the long trailing legs in flight. When seen at ground level, pelicans are usually swimming in water, whereas whooping cranes walk either in shallow marshes or agricultural fields.
The whooping crane is fully protected under the Endangered Species Act. The public is cautioned not to shoot or disturb these birds, as they could be frightened into wires or other obstacles. "Let's all do our part to assist these birds as they recover from the brink of extinction" said Tom Stehn, Whooping Crane Recovery Coordinator for the U.S. Fish and Wildlife Service.
Captive populations of whooping cranes include 98 adults and 35 chicks at three breeding centers, the Patuxent Wildllife Research Center in Maryland, the International Crane Foundation in Wisconsin, and the Calgary Zoo in Canada. Whoopers are on display at the San Antonio zoo.
Recovery efforts for the crane are coordinated by a Whooping Crane Recovery Team, consisting of 10 members appointed by directors of the Canadian Wildlife Service and the U.S. Fish and Wildlife Service. At the team's last meeting in Calgary, the team recommended that future recovery efforts focus on building the non-migratory flock in Florida and establishing a migratory flock of whooping cranes east and completely separate from the Aransas-Wood Buffalo flock. Suggested locations included marsh habitat in central Wisconsin and a wintering area at the Chassahowitzka National Wildlife Refuge on the southwestern coast of Florida.
An assessment of the best summering areas in Wisconsin is under way, with a recommendation on how best to proceed expected next year. No additional releases of whooping cranes in the Rocky Mountains are planned at this time, according to Stehn. However, if certain habitat criteria are met and mortality factors (e.g., powerlines and avian tuberculosis) identified by the Recovery Team addressed, and if State wildlife agencies support further reintroductions, then the Fish and Wildlife Service may consider adding to the Rocky Mountain population sometime in the future.
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