with a second reintroduction technique called Direct Autumn Release (DAR). Young cranes are released in small groups with older, now wild whooping cranes, with the intent that they will learn the migration route from these more experienced birds. After learning the migration route by following the ultralight aircraft or older cranes to the wintering areas, the young cranes make the return flight to their summering grounds in the north on their own the following spring. In December 2011, the Operation Migration escorting nine cranes was interrupted by the Federal Aviation Administration due to a regulation prohibiting paid pilots of ultralight aircraft. After a month with the cranes kept in a pen, the FAA finally granted a one-time exemption to allow completion of the migration. On January 22, 2016, the United States Fish and Wildlife Service announced that after the 2016 season it would end its support of the use of ultralight aircraft to lead whooping cranes from Wisconsin to the Florida Gulf Coast each autumn. A conclusion by experts in whooping crane biology that human intervention such as ultralight flights and costumed humans helping to care for chicks has impaired the ability of the cranes to learn the parenting skills necessary to raise chicks in the wild prompted the Fish and Wildlife Service's announcement: Despite the release of 250 whooping cranes in Wisconsin in 2001 – of which 93 survived in January 2016 – only 10 chicks have fledged and survived to adulthood and, since 2005, only five breeding pairs have produced chicks that were born in the wild and fledged. Agreeing with the need to minimize human interaction with chicks, the International Crane Foundation supported the Fish and Wildlife Service's decision, although Operation Migration opposed it, claiming that the ultralight flights nonetheless help whooping cranes to survive. See also Bill Lishman, co-founder who first led birds with ultralight aircraft Fly Away Home, feature film inspired by Lishman's work References Further reading Operation Migration online Field Journal Lishman, William. Father Goose. Crown, 1996. . Whooping Crane Eastern Partnership External links Operation Migration archived website at Internet Archive Ornithology in the United States Ornithology in Canada Ornithological organizations Bird conservation