Sandhill crane

Sandhill cranes are large waterbirds known for their gracefulness and mating dances. Their low, trumpeting calls are another distinguishing feature.

Kingdom: Animalia

Phylum: Chordata

Class: Aves

Order: Gruiformes

Family: Gruidae

Genus: Antigone

Species: Canadensis

Even though their name might suggest they live only in sandhills, sandhill cranes live in various habitats. They usually live in open countryside away from people and where they have plenty of shallow water. In the south of their range, they live in shallow marshes surrounding lakes, prairies, savannas, and farmlands. Farther north, they are at home in wet tundras near the Arctic.

The lesser, greater, and Canadian sandhill subspecies migrate each year. Their migrations carry them up to 400 miles (645 kilometers) each day. They generally fly quite high, as was witnessed in 1963 when one flock was seen above the peak of Mt. McKinley in Alaska, which rises to 20,000 feet (6,000 meters).

The bodies of sandhill cranes are 1 1/2 to 4 feet (45 centimeters to just over one meter) long from the tips of their toes to the tips of their long, straight bills. They are upright birds nearly as tall standing up as they are long. They weigh between 7 and 11 pounds (three to five kilograms). Wingspans of 6 to 6 1/2 feet (nearly two meters) allow the cranes to fly great distances at surprising altitudes. Their powerful wings move easily with long strokes alongside their stretched and streamlined bodies and necks. Alone or in a flock, sandhill cranes in flight are impressive.

Juvenile cranes have gray plumage, or feathering, like the adults. The younger birds' heads and necks may be light brown to gray, whereas the adults have gray heads and necks. Adults also have red patches on the crowns, or tops, of their heads. The juveniles' light brown crowns do not turn red until they are 2 1/2 years old when they receive their full adult plumage.

The diets of sandhill cranes change during the appropriate seasons of the year and depending on what is available in their various ranges. They may travel several miles (kilometers) in the morning to find food and may find it in fresh and salt water, which is unusual among birds. Their diets include seeds, shoots, leaves, and fruit, and crops like corn and potatoes. They also dig for roots and tubers with their long, broad bills. Crabs, amphibians, mollusks, eels, and small fish living in the shallow marshes and reedbeds fall prey to the slow-stalking cranes. Once they see their prey, the cranes quickly thrust their bills forward and seize their prey. With arched necks, cranes swallow their prey whole. In the evening, crane flocks return to their large roosting, or sleeping, sites.

Sandhill cranes do not face much danger from natural predators. Their eggs and young birds may fall prey to predatory mammals. Of greater threat are hunters who may shoot the birds, even though the cranes have received the protection of government legislation.

Migratory subspecies lay eggs from April to May and non-migratory subspecies lay eggs between December to August. A male and female dance with each other, flapping their wings and jumping up and down, before they mate. The pair forms a life-long bond. After mating, they build a nest from dry plant materials in a reedbed of a marsh or swamp. She lays one to three white eggs with light brown spots. The parents incubate the eggs for about one month, taking turns every two days. After the young hatch, both parents feed and care for them. The chicks can leave the nest within a few days and fledge, or fly for the first time, after 65 to 75 days. The chicks become independent at one year old, but the family may stay together for 9 to 10 months. They can mate for the first time when they are three years old.

As the end of the breeding season approaches, adults molt, or lose, nearly all their plumage. They cannot fly for five or six weeks as new plumage grows. While this places the adults in danger, it benefits the young because the parents stay with them and continue caring for them.

After mating and molting, the cranes in northern regions migrate south for the winter. Those in southern regions stay where they are year-round. Migrating cranes follow the same routes each year and fly in V-formations. They return to the same winter grounds each year and return to the same breeding and nesting sites in the spring.

Migrating and breeding cranes have loud, trumpeting calls that can be heard from some distance.

One sandhill crane in a zoo lived to be 55 years old. In the wild, they live for up to 20 years. Crane species have been symbols of long life in Japanese mythology for centuries. It was believed they lived 1,000 years.

Bibliography

"Sandhill Crane." National Audubon Society, www.audubon.org/field-guide/bird/sandhill-crane. Accessed 15 Apr. 2024.

"Sandhill Crane." Smithsonian's National Zoo & Conservation Biology Institute, nationalzoo.si.edu/animals/sandhill-crane. Accessed 15 Apr. 2024.