Whooping cranes are primarily white with contrasting dark legs and bill, as well as black tips on their primary wing feathers. Their eyes are yellow, and there is a pinkish hue at the base of the bill. Young are cinnamon in color along the back, with a dull gray or brown on the underbelly and blue eyes.
Whooping cranes are the tallest birds in North America, standing an impressive 5 feet (1.5 m) tall with a 7-foot (2-meter) wingspan.
Native to North America, almost all populations of whooping cranes are gone. One self-sustaining population of whooping cranes exists in the wild, which winters in the Aransas National Wildlife Refuge in Texas, then migrates to Wood Buffalo National Park in the Northwest Territories to breed. A series of reintroduced experimental non-essential populations on the East Coast and in the Rocky Mountain region have experienced varying degrees of success, but none have become self-sustaining.
Breeding occurs in prairie wetlands alongside shallow lakes, ponds and marshes that offer an abundance of vegetation. Cranes choose breeding habitats for their protection from predators, ability to visually detect surroundings and potential threats, and availability of food.
During migration, a 2,500-mile (4,000-kilometer) journey, whooping cranes will seek out wetlands and agricultural fields along the way. Brackish bays and coastal marshes are the preferred habitat for wintering.
Vocal communication is essential for whooping cranes, and can be used to indicate danger, mating and flight, among other situations. Common predators for whooping cranes include black bears, wolves, foxes, coyotes and eagles.
Whooping cranes are omnivorous animals whose diet depends upon available food in their region. Blue crabs and wolfberries (also known as goji berries) are a staple of their diet, and can be supplemented with terrestrial and aquatic invertebrates, snakes, rodents and agricultural waste.
Whooping cranes at the Smithsonian's National Zoo are given crane pellets with smelt, and insects as enrichment items.
Whooping cranes are monogamous birds that form pairs around 2 or 3 years of age. They will seek out a new mate if their initial mate dies. Pairs bond through a series of courtship rituals, including walking and calling in unison, and partaking in courtship dancing. After forming a pair, whooping cranes begin nesting around four years of age, and breed seasonally. Mating frequently occurs at daybreak.
Both males and females help built the nest, which normally consists of a flat mound of vegetation, surrounded by water. The female lays two eggs that hatch after an incubation period of 30 to 35 days. Eggs are primarily laid between April and May, and it is common for only one chick to survive. Chicks fledge between 80 and 100 days, but young remain with their parents until nine months of age. Maturity is reached at four years of age.
Whooping cranes are diurnal and will roost on the ground at night.
The average lifespan for whooping cranes is 22 to 30 years in the wild, and 35 to 40 years in human care.
Whooping cranes have made a dramatic recovery in the past century, coming back from the brink of extinction. This species was reduced to fewer than two-dozen individuals in the early 1940s, and while current population numbers are up for debate, there is a consensus that whooping cranes are recovering, with breeding and reintroduction plans ongoing.
Historically, population declines were attributed to hunting and destruction of nesting habitats in favor of agricultural development. Current hazards include collisions with power lines, natural predation, inclement weather, climate change and oil spills.
USFWS calls whooping cranes "a flagship species for the North American wildlife conservation movement." International recovery plans are underway to increase the size and genetic diversity of the wild flock. Experimental releases, breeding under-represented strains and even teaching captive-bred birds to migrate are all actions currently in place to help whooping cranes.