18 whooping cranes left the Necedah National Wildlife Refuge in central Wisconsin on October 5, 2006. Since 2001, a unique partnership of organizations, state and federal agencies, and volunteers have been taking on an attempt to bring back an endangered species. Serving as surrogate parents, ultralight aircrafts guide young whooping cranes from Wisconsin to Florida at Chassahowitzka National Wildlife Refuge. This ultralight-led migration technique, implemented by Operation Migration (operationmigration.org), serves as the main reintroduction method.