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Cranes

Marjorie Cahak Gibson

Natural History

Cranes are classed among the oldest families of birds. Of the 15 species in the Gruidae family
worldwide, 9 are threatened or endangered. Cranes are tall, stately birds with long necks and legs
and heavy bills. They have distinctive silhouettes with the tertial feathers drooping over the rump
in a bustle. Cranes are best known for strong mate fidelity, intricate “mating dances,” and the prac-
tice of siblicide.
Two species are found in North America, with another species, the Common Crane (Grus grus)
of Eurasia, being sighted occasionally. The Sandhill Crane (Grus Canadensis) has six subspecies,
including Canadian, Greater, Lesser, Florida, Mississippi, and Cuban. The Whooping Crane (Grus
Americana) is endangered in North America.
Sandhill Cranes are 34–48 in. (0.8–1.2 m) tall with wingspans of 73–90 in. (1.8–2.3 m), with vari-
ation in size depending on the subspecies. Whooping Cranes are 52 in. (1.3 m) tall with wingspans
of 87 in. (2.2 m). Successful captive-breeding programs for Whooping Cranes have been estab-
lished, and these birds are currently being reintroduced to regions within the U.S. With continued
success of captive-breeding and reintroduction, it may be possible to encounter wild Whooping
Cranes in need of rehabilitation within the next decade.
Cranes are long-lived and monogamous. They nest in marshy areas and build simple nests of
vegetation gathered from around the nest site. The gathering of nesting material plays an impor-
tant role in nesting because a watery barrier must be created around the nest site. This act may
contribute to the reproductive success of cranes. Both male and female incubate the two eggs,
which hatch asynchronously in 28–36 days.
Young cranes are called colts. Crane colts can be very aggressive to each other and siblicide is
common. Asynchronous hatching gives the older chick an advantage but leaves the second egg and
resulting chick as a “backup” if the first colt should perish. If both chicks survive past hatch, they
are generally separated, with each adult taking one chick and acting as its primary parent. In this
way, the young are physically separated until tolerance is attained.
Crane colts are precocial at hatch. They are covered with thick, rusty brown-colored down. They
are active after hatch and can leave the nest the same day. Young cranes follow their parent, often
walking underneath the abdomen of the adult as they move through the marsh. They can swim
short distances. There is a wide variety of vocalizations that occur between adult cranes and their
young. Sounds can change from a soft pumping noise to an aggressive trumpet when danger is near.

Hand-Rearing Birds, Second Edition. Edited by Rebecca S. Duerr and Laurie J. Gage.
© 2020 John Wiley & Sons, Inc. Published 2020 by John Wiley & Sons, Inc.