For the first time in a decade, there will be no ultralightled class of whooping cranes heading south from Necedah National Wildlife Refuge in Wisconsin this year. But the refuge will remain an integral player in the effort to restore a migratory whooping crane population to eastern North America.
The whooping crane is a critically imperiled species, with just a single wild population of 281 birds that winter at Aransas National Wildlife Refuge in Texas. The goal of the multiagency Whooping Crane Eastern Partnership (WCEP), of which the U.S. Fish and Wildlife Service is a member, is to create a second selfsustaining flock of at least 120 birds and 30 breeding pairsa population that can be maintained without the current need to add birds from captive flocks.
For the past 10 years, whooping crane chicks have followed an ultralight aircraft from Necedah Refuge to Chassahowitzka National Wildlife Refuge in Florida. More recently, some cranes have been led to St. Marks National Wildlife Refuge in Florida. After learning the migration route south in the fall, the young birds migrate north on their own in the spring. This 10year effort, coupled with other captive breedingandrelease programs, has generated a population of about 100 cranes.
Although the introduction of migrating birds has been a success, there have been problems with reproduction and nest abandonment. In the past three years, there have been 33 unsuccessful nests at Necedah Refuge, with successful nests producing only two chicks that fledged. The problem is acute if the cranes nest early in April rather than later in that month. Since 2005, all early nests have failed at Necedah Refuge.
Because male whooping cranes return to their natal areas to breed, they must be released directly into, or very near, desirable nesting locations. So, WCEP decided that no more cranes would be released for the ultralight project at Necedah until the nest abandonment issue has been resolved.
Help From Many Directions
Biologists and researchers are trying several projects to help the cranes, including research to determine if too many black flies early in the season are causing the cranes to abandon their nests. Although high water prevented a full application of larvacide, a partial black fly treatment was completed this spring, and its success is being evaluated. At Necedah Refuge, wildlife biologist Rich King will continue to watch the nests like, well, a hawk to see if and when they are abandoned.
WCEP is also planning to lead an ultralight class of crane chicks to the Florida refuges this year from a nonrefuge site in eastern Wisconsin. Chicks may be released at Horicon National Wildlife Refuge, WI, soon, too.
Necedah Refuge will continue to receive crane chicks from Patuxent Research Refuge, MD, but for the first time these will be raised by their crane parents rather than by humans in crane costumes. The challenge is to raise a healthy parentreared chick by monitoring it from a distance, says U.S. Geological Survey wildlife biologist Glenn Olsen, rather than having humans dressed as cranes working closely with the chick.
The Whooping Crane Eastern Partnership has embarked on a new, fiveyear strategic plan. Many questions remain, but were going in the right direction, says Billy Brooks, a member of the Services WCEP Guidance Team. Weve established a migratory flock of whooping cranes, and we hope through continued releases of whooping cranes into Wisconsin that we will establish a selfsustaining viable population of cranes.
Karen Leggett is a writereditor in the Refuge System Branch of Communications.