Half of the flock is expected to remain at St. Marks NWR for the winter. The rest of the birds will continue south to Chassahowitzka NWR, 65 miles north of St. Petersburg.

"St. Marks has been anticipating the birds arrival for months, and the outpouring of community support around Wakulla and Leon counties has been phenomenal," said Terry Peacock, Refuge Manager at St. Marks NWR. "We are thankful for the help of all of our volunteers who have assisted with pen set-up and helped with other preparations around the refuge."

The Whooping Crane Eastern Partnership (WCEP), an international coalition of public and private groups, leads the annual project, now in its eighth year, in an effort to reintroduce this endangered species in eastern North America. Each fall, pilots from Operation Migration (OM), a non-profit organization and founding WCEP partner, lead a new generation of whooping cranes behind their ultralight aircraft to wintering grounds in Florida. The cranes will make the return flight to the Upper Midwest on their own in the spring.

This year's migration began from Necedah NWR on Oct. 17, with four ultralight aircraft leading the birds southward. To help speed the migration and improve safety for the birds and the pilots, a new route was developed this year that took the team around the Appalachian Mountains rather than over them, taking them through the state of Alabama for the first time. The ultralight-led flock also passed through Wisconsin, Illinois, Kentucky, Tennessee, and Georgia before crossing the Florida border.

One of the oldest refuges in the National Wildlife Refuge System, St. Marks National Wildlife Refuge covers 70,000 acres and more than 60 miles of coastline in Wakulla, Jefferson and Taylor counties along the Gulf Coast of northwest Florida. The landscape includes coastal marshes, islands, tidal creeks and estuaries of seven north Florida rivers, and the refuge is home to a diverse community of plant and animal life. The refuge was established in 1931 to provide wintering habitat for migratory birds.

Whooping cranes were on the verge of extinction in the 1940s. Today, there are only about 500 birds in existence, 350 of them in the wild. Aside from the 73 Wisconsin-Florida birds, the original population of whooping cranes nests at the Wood Buffalo National Park in the Northwest Territories of Canada and winters at the Aransas National Wildlife Refuge on the Texas Coast.

Read the complete press release.

Video Journey of St. Mark's National Wildlife Refuge. (Courtesy of Drew Smith)

Photo Credit: Joe Duff/Operation Migration