Date of this Version
Clegg, Kent, James C. Lewis, and David H. Ellis. Use of ultralight aircraft for introducing migratory crane populations. In: Urbanek RP, Stahlecker DW, eds. 1997. Proceedings of the Seventh North American Crane Workshop, 1996 Jan 10-13, Biloxi, Mississippi. Grand Island, NE: North American Crane Working Group. pp. 105-13.
Greater sandhill cranes (Grus canadensis tabida) were used as the research surrogate for whooping cranes (Grus americana) to determine if captive-reared cranes could be led by an ultralight aircraft (UL) along a migration route and if, after release on a wintering area, they would integrate with wild cranes and migrate north in spring to their natal area without assistance. In 1995, KRC raised 15 cranes to fledging and trained them to respond to his vocal imitation of a sandhill crane brood call. Chicks learned to follow him as he walked, drove an all-terrain vehicle (ATV) , or piloted a UL. The caretakers were not in crane costumes. Cranes were tame but allowed to roam at will without accompanying humans part of the day and were penned at night. Daily excursions provided exposure to habitats, foods, and predators the birds would encounter after release into the wild. In mid-October 1995, 11 radio-tagged cranes were led in migration from Grace, Idaho, to Bosque del Apache National Wildlife Refuge (BdANWR), central New Mexico, and released near wild wintering sandhill cranes. The 1,204-kIn migration took 11 days, including I day when the aircraft were grounded due to a winter storm. Hazards encountered enroute included mountainous terrain, turbulent air, and attacks by golden eagles (Aquila chrysaetos). On the wintering grounds hazards included crane hunters and coyotes (Canis latrans). Within 2 days after release at the BdANWR wintering site, the research cranes were associating with and imitating the behavior of wild cranes. The 4 surviving birds migrated north in spring 1996, and in May 1996, 2 were within 53 km of their Idaho natal area.