Courtesy Kenn Kaufman
Although thought to have never been very numerous, these birds once ranged throughout the plains and prairies of central North America, wintering on the Gulf Coast, parts of the Atlantic coast, and as far south as northern Mexico. They are now absent from much of their historic range. The largest (and only remaining wild) flock of Whooping Cranes spends the summer in Wood Buffalo National Park, on the border between Alberta and the Northwest Territories, and winters in the marshlands of the Aransas National Wildlife Refuge on the Gulf Coast of Texas. Conservation efforts undertaken over the last few decades have aimed to reintroduce the species to a number of areas. As a result of these efforts, an introduced population now migrates between Wisconsin's Necedah National Wildlife Refuge and the Chassahowitzka National Wildlife Refuge on Florida's Gulf Coast. Yet another population, this one non-migratory, has been introduced to the Kissimmee Prairie in central Florida. Experimental flocks have been released in other areas of the country in recent decades, but these releases have not proven successful.
Whooping Cranes rely on marshy wetland habitats at all times of year, whether on the breeding grounds, at migratory stopovers, or on the wintering grounds. Agricultural areas and drier, upland habitats surrounding wetlands are also used for feeding.
Omnivorous creatures, Whooping Cranes make use of a wide variety of foods found in wetlands or on adjacent upland habitats. Whooping Cranes are known to eat crabs, frogs, snakes, mollusks and fish, as well as mice, insects, plant tubers, nuts, berries and agricultural grains. A wide range of feeding methods are employed, from probing in water or mud, to digging up tubers, plucking berries or nuts from shrubs, gleaning waste grains from fields, or grabbing prey directly from the ground or water.
Relatively long-lived, the Whooping Crane pairs with one partner for life. Partnerships often begin to form when the birds are as young as two, but breeding doesn't take place until the third or, more likely, fourth year. As pair bonds solidify, the birds interact with one another in a variety of ways, the most spectacular of which is a type of "Crane Dance." In the dance ritual, one bird will engage the other through a series of movements such as bowing, flapping and leaping. If successfully enticed, the other member of the pair will join in, and soon both birds run about together, performing a complicated series of motions – leaping and bowing, stretching and flapping, and bouncing into the air in unison. This majestic display is a good indication that strong pair bonds have been formed.
Paired cranes establish a territory, which will be used year after year. The male defends the territory, and the female sets about building the nest. Nests are often located in shallow water, where the female gathers nesting materials into a small pile with a slight depression at the top. Only two eggs are laid per clutch. Eggs are about four inches in length, and white, creamy, or buff in color, with light brownish blotches at one end. Both members of the pair incubate the eggs for about 35 days. Whooping Crane chicks are well developed upon hatching, capable of moving about and swimming almost immediately. Parents and young stay close to the nest for the first several days, but soon begin to wander further afield until the young are capable of flight at about three months old. Cranes remain together in family groups throughout the winter, and often right through to the following summer, but young birds eventually move off to associate with other birds of similar age.
Unlike most other birds, young Whooping Cranes must be taught how to migrate. Historically, migratory and non-migratory populations of these birds existed, and the same is true today. The Wood Buffalo – Aransas population migrates approximately 2500 miles each way along North America's Midwest flyway, with adult cranes leading the young. The Wisconsin – Florida population is also migratory, but in this case, the majority of young cranes make their first flights behind a human and the famous Operation Migration ultralight aircraft. The first such flight took place in the fall of 2001, when scientists led a group of captive-bred juvenile birds to Florida. In the spring of 2002, these birds returned to Wisconsin on their own, in yet another remarkable success story for the species. The only current non-migratory population is the introduced flock of central Florida.