The International Crane Foundation announced Monday that Ducky, an endangered female whooping crane the foundation planned to release into the wilds of Wisconsin this fall, died on Thursday after becoming infected with Highly Pathogenic Avian Influenza, a strain of avian flu. Foundation officials said in a news release that Ducky's death marks the first time the strain has killed a whooping crane. Only about 700 wild whooping cranes are left in North America, according to the foundation. "Each Whooping Crane is invaluable — not only to our organization, but to the survival of the entire species." It works to protect whooping cranes around the globe through a network of experts in 50 countries.