Into The Wild

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Three young Whooping Cranes (with brown feathers) join a flock of adult cranes in Wisconsin. The young cranes will follow the experienced older birds on their first fall migration south to Florida. Photo by Dr. Richard Urbanek, USFWS

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Over the last 35 years a series of reintroduction projects have been developed to establish new wild Whooping Crane populations. The projects have had varying success, but as each project builds on previous attempts we are learning what techniques work most effectively. Today, as a result of years of dedication, a second Whooping Crane population numbering over 100 birds migrates through the eastern United States. In 2010 two chicks successfully fledged in this population - a symbol of hope for the future of Whooping Crane conservation.

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Biologists place Whooping Crane eggs in Sandhill Crane nests in Idaho.

Important Lessons...

In 1975 biologists started an ambitious project to establish a migratory Whooping Crane population in the Rocky Mountain states - the first reintroduction attempt for this endangered species. 

The biologists looked to wild Sandhill Cranes to stand in as surrogate parents for the reintroduced Whooping Cranes, and placed Whooping Crane eggs in Sandhill Crane nests at Grays Lake National Wildlife Refuge (NWR) in Idaho.

The Sandhill Cranes hatched and raised the Whooping Crane chicks, and the chicks learned the migration route to Bosque del Apache NWR in New Mexico from their surrogate parents. However, when the Whooping Crane chicks reached breeding age they did not pair with other Whooping Cranes, as they identified with their Sandhill Crane foster parents. As a result, the project was ended in 1989, and by 2002 no Whooping Cranes remained in the region.

Florida Non-Migratory Population

Under the guidance of the Whooping Crane Recovery Plan, in 1993 biologists began a project to reintroduce Whooping Cranes to Florida. The cranes were raised in captivity by adult Whooping Cranes, or by biologists dressed in crane costumes, to prevent the birds from imprinting incorrectly (biologists learned this lesson from initial reintroduction efforts in Idaho twenty years earlier - see right side bar). This population is non-migratory, because the cranes were released in Florida and never taught a migration route.

In 2002, a pair from this flock hatched and fledged a chick - the first wild Whooping Crane chick to hatch from this reintroduction effort and the first in the United States since 1939. However, reproduction has been slower than anticipated, and mortality rates have been high, primarily due to predation. Drought and development are additional factors affecting this population, and as a result reintroduction efforts in Florida ended in 2008. There are approximately 25 non-migratory Whooping Cranes in the Florida Non-Migratory Population as a result of this project.

Whooping Crane Eastern Partnership

wcep_logoBuilding upon experience gained through the earlier Rocky Mountain and Florida reintroductions, in 2001 a new project to restore a migratory Whooping Crane population to eastern North America was started. The project is being undertaken by the Whooping Crane Eastern Partnership (WCEP), of which ICF is a founding member. Researchers are using two methods to reintroduce the cranes and teach the young birds their migratory route from central Wisconsin, south to Florida.

Ultralight-led Migration

Whooping Crane eggs from captive breeding centers, including ICF, are hatched at the Patuxent Wildlife Research Center, where the chicks are first exposed to ultralight aircraft (below) and learn to follow the ultralights on the ground. As they grow older, the chicks are transported to the White River Marsh State Wildlife Area in Wisconsin, where they spend the summer learning to fly behind the ultralights. In the fall, the chicks follow the ultralights to the Chassahowitzka and St. Marks National Wildlife Refuges along Florida’s Gulf Coast. WCEP project partner, Operation Migration, leads the young Whooping Cranes on migration with the ultralight aircraft. 

The cranes learn the ~1,200 mile migration route during their first trip south in the fall, and are able to make the return journey on their own the following spring. In subsequent years, the cranes continue to migrate on their own. Biologists from ICF and the U.S. Fish and Wildlife Service track and monitor the cranes year-round after the birds’ first migration south.

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View Cranecasts on ICF's YouTube Channel

View our series of four Cranecast videos focusing on ICF's captive breeding and reintroduction program.

Direct Autumn Release

Since 2005, a second method of rearing and reintroducing Whooping Cranes, called Direct Autumn Release (DAR), has been conducted by ICF and the U.S. Fish and Wildlife Service. DAR chicks are raised by biologists at ICF’s Felburn/Leidigh Chick Rearing Facility using costume rearing protocols, which include a no-talking rule and costumes designed to mask the human form. The chicks are never exposed to humans (un-costumed) prior to release. While at ICF, the chicks are housed next to adult Whooping Cranes that serve as imprinting models. 

Before the chicks fledge, or learn how to fly, they are transferred to the Necedah National Wildlife Refuge in western Wisconsin, where they live in specially-constructed facilities. The chicks are often visited by older, wild Whooping Cranes, which further aid in proper imprinting. Each day the chicks are led out of the pen by costumed staff for exercise and exploration of refuge habitats. Several weeks prior to their release, the chicks are transferred to Horicon National Wildlife Refuge in eastern Wisconsin, their ultimate release location.
 
Once the DAR chicks have fledged they are released at locations where older cranes are present. The young DAR birds learn the migration route by following these older cranes south in the fall.  The cranes are tracked during their first autumn migration and thereafter by ICF and U.S. Fish and Wildlife Service staff using radio and satellite telemetry.

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DAR chicks at the Necedah National Wildlife Refuge.