Grus canadensissandhill crane

Ge­o­graphic Range

In North Amer­ica, this species breeds as far north as Alaska and the Arc­tic coast of Canada south into the Great Lakes re­gion and west­ward across Idaho, Nevada and Ore­gon. It also breeds in the ex­treme south­east­ern United States and Cuba. The win­ter range of this species in­cludes parts of Cal­i­for­nia, New Mex­ico, Ari­zona, Texas, Geor­gia, Florida and north­ern Mex­ico. Pop­u­la­tions of sand­hill cranes are also found in north­east­ern Siberia, Andyr­land, and on the Chyukot­ski penin­sula and Wrangel Is­land. (Tacha, et al., 1992)

Habi­tat

Most sand­hill crane pop­u­la­tions nest in open grass­lands, such as wet mead­ows, and fresh­wa­ter marshes or bogs. There are six sub­species of sand­hill cranes, and each typ­i­cally nests in the open, wet grass­land habi­tats of their re­gion. The Cuban pop­u­la­tion of sand­hill cranes (Grus canaden­sis ne­siotes) is an ex­cep­tion, in­hab­it­ing dry, iso­lated re­gions, some­times in rocky and moun­tain­ous ter­rain.

Sand­hill cranes pre­fer to be far from human habi­ta­tion. How­ever, dur­ing mi­gra­tion, they are com­monly seen feed­ing on crops and crop residue in agri­cul­tural fields. At night they con­gre­gate to roost in large marshes. (Tacha, et al., 1992)

Phys­i­cal De­scrip­tion

Sand­hill cranes are large birds with heavy bod­ies and long necks and legs. They stand about 1.2 m tall, with wing spans of about 2 m. They are uni­formly gray­ish, with a white cheek and a bald red crown. Sand­hill cranes can be dis­tin­guished from other large wad­ing birds in flight by their out­stretched neck, and their wing­beats, which are a slow down­ward beat fol­lowed by a quick up­ward flick.

Male and fe­male sand­hill cranes are sim­i­lar in ap­pear­ance, though males are usu­ally larger than fe­males. For ex­am­ple, males of the G. c. canaden­sis sub­species av­er­age 3.75 kg whereas fe­males av­er­age 3.34 kg. Ju­ve­nile sand­hill cranes tend to be much more brown­ish than adults.

There are six sub­species of sand­hill cranes. These sub­species are dis­tin­guished based upon mor­phol­ogy (size) and ge­o­graphic sep­a­ra­tion. (Pe­ter­son, 1980; Tacha, et al., 1992)

  • Sexual Dimorphism
  • male larger
  • Range mass
    3200 to 5200 g
    112.78 to 183.26 oz
  • Average wingspan
    2 m
    6.56 ft

Re­pro­duc­tion

Sand­hill cranes are peren­ni­ally monog­a­mous. Breed­ing pairs re­main to­gether from year to year, main­tain­ing the pair bond by per­form­ing courtship dis­plays, re­main­ing in close prox­im­ity and call­ing to­gether in uni­son. Breed­ing pairs form dur­ing spring mi­gra­tion. This species is noted for its elab­o­rate courtship dis­plays. Five courtship dis­plays have been iden­ti­fied as part of "danc­ing," the pri­mary mech­a­nism of pair for­ma­tion in this species. These dis­plays are the Up­right wing stretch, Hor­i­zon­tal head pump, Bow, Ver­ti­cal leap and Ver­ti­cal toss. Three courtship dis­plays are used ex­clu­sively by paired adults to main­tain the pair bond and syn­chro­nize re­pro­duc­tive de­vel­op­ment. These are the Bill up, Cop­u­la­tion and Uni­son call dis­plays. (Tacha, et al., 1992)

Sand­hill cranes raise one brood per year. In non-mi­gra­tory pop­u­la­tions, egg-lay­ing can begin as early as De­cem­ber or as late as Au­gust. In mi­gra­tory pop­u­la­tions, egg-lay­ing usu­ally be­gins be­tween early April and late May. Both mem­bers of a breed­ing pair build the nest using plant ma­te­r­ial from the sur­round­ing areas. Nest sites are usu­ally in marshes, bogs, or swales, though cranes will oc­ca­sion­ally nest on dry land.

The fe­male lays 1 to 3 (usu­ally 2) eggs that are oval-shaped and dull brown with red­dish brown mark­ings. Both par­ents par­tic­i­pate in in­cu­ba­tion, which lasts 29 to 32 (usu­ally 30) days. In­cu­ba­tion be­gins with the lay­ing of the first egg and con­tin­ues until the sec­ond egg has hatched. The chicks are pre­co­cial; they hatch cov­ered in down, with their eyes open and are able to leave the nest within 24 hours of hatch­ing. The par­ents brood the chicks for up to 3 weeks after hatch­ing. They feed the young in­ten­sively for the first few weeks, and with de­creas­ing fre­quency until they reach in­de­pen­dence at 9 or 10 months old.

The chicks re­main with their par­ents until 1 or 2 months be­fore the par­ents begin lay­ing the next clutch of eggs. After leav­ing their par­ents, the chicks form no­madic flocks with other subadults and non-breed­ers. They re­main with these flocks until they form breed­ing pairs and begin breed­ing be­tween the ages of 2 and 7 years old. (Tacha, et al., 1992)

  • Breeding interval
    Sandhill cranes raise one brood per year.
  • Breeding season
    In non-migratory populations, egg-laying can happen any time between December and August. In migratory populations, sandhill cranes usually lay their eggs in April and May.
  • Range eggs per season
    1 to 3
  • Average eggs per season
    2
    AnAge
  • Range time to hatching
    29 to 32 days
  • Average time to hatching
    30 days
  • Range time to independence
    9 to 10 months
  • Range age at sexual or reproductive maturity (female)
    2 to 7 years
  • Range age at sexual or reproductive maturity (male)
    2 to 7 years

Sand­hill cranes pro­vide ex­tended bi­parental care to their young. Both mem­bers of a breed­ing pair build the nest, in­cu­bate the eggs and feed and pro­tect the chicks for up to 10 months after hatch­ing. (Tacha, et al., 1992)

  • Parental Investment
  • precocial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • protecting
      • male
      • female
  • pre-weaning/fledging
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • post-independence association with parents

Lifes­pan/Longevity

Sand­hill cranes that reach in­de­pen­dence are ex­pected to live about seven years. The old­est known sand­hill crane lived at least 21.6 years.

Be­hav­ior

Sand­hill cranes are di­ur­nal and par­tially mi­gra­tory. North­ern pop­u­la­tions move south dur­ing the win­ter months whereas south­ern pop­u­la­tions re­main near the breed­ing sites year round.

Cranes are usu­ally found in pairs and fam­ily groups. Dur­ing the mi­gra­tion and win­ter, fam­ily groups may join with non-mated cranes to form sur­vival groups that feed and roost to­gether. These sur­vival groups often con­gre­gate at mi­gra­tory stag­ing areas and on the win­ter­ing grounds. (Tacha, et al., 1992)

  • Range territory size
    0.10 to 0.85 km^2

Home Range

Two stud­ies res­i­dent sand­hill crane pop­u­la­tions in Florida es­ti­mated av­er­age home ranges of 657 and 1366 hectares.

Com­mu­ni­ca­tion and Per­cep­tion

Sand­hill cranes com­mu­ni­cate pri­mar­ily using phys­i­cal dis­plays (see Mat­ing Sys­tems sec­tion) and vo­cal­iza­tions. Adult sand­hill cranes have a reper­toire of more than a dozen calls, which can be de­scribed as vari­a­tions on "trills", "purrs" and "rat­tles". Calls are used in ter­ri­to­r­ial ad­ver­tise­ment, so­cial in­ter­ac­tions and to no­tify oth­ers of a nearby preda­tor. Breed­ing pairs may call in duet in order to ad­ver­tise their oc­cu­pancy of a ter­ri­tory. (Tacha, et al., 1992)

Food Habits

Sand­hill cranes are om­niv­o­rous birds that use their bills to probe for sub­sur­face food and glean seeds and other foods. These birds feed on land or in shal­low marshes with veg­e­ta­tion. Foods vary de­pend­ing on what is avail­able. Cul­ti­vated grains such as corn, wheat and sorghum are a major food source in their diet when avail­able. In north­ern lat­i­tudes, a wider va­ri­ety of foods are con­sumed, in­clud­ing berries, small mam­mals, in­sects, snails, rep­tiles, and am­phib­ians. (Tacha, et al., 1992)

  • Animal Foods
  • mammals
  • amphibians
  • reptiles
  • insects
  • mollusks
  • Plant Foods
  • seeds, grains, and nuts
  • fruit

Pre­da­tion

When ap­proached by an avian preda­tor, sand­hill cranes fly at the preda­tor, kick­ing it with their feet. When ap­proached by a mam­malian preda­tor, sand­hill cranes move to­ward the preda­tor with their wings spread and their bill pointed at the preda­tor. If the preda­tor per­sists, sand­hill cranes will at­tack, hiss­ing, stab­bing with their bills and kick­ing with their feet. (Tacha, et al., 1992)

Ecosys­tem Roles

Young and sick sand­hill cranes pro­vide food for their preda­tors. Sand­hill cranes af­fect the pop­u­la­tions of species that they prey upon. They also host at least 24 dif­fer­ent species of par­a­sites. (Tacha, et al., 1992)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Sand­hill cranes feed on in­sects and ro­dents that may dam­age crops. (Tacha, et al., 1992)

  • Positive Impacts
  • controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Sand­hill cranes feed on crops where they are avail­able.

  • Negative Impacts
  • crop pest

Con­ser­va­tion Sta­tus

Sand­hill cranes are pro­tected under the U.S. Mi­gra­tory Bird Act and CITES Ap­pen­dix II. Two sub­species of sand­hill cranes, Grus canaden­sis ne­siotes (Cuba sand­hill crane) and Grus canaden­sis pulla (Mis­sis­sippi sand­hill crane), are fed­er­ally en­dan­gered in the United States. Low re­pro­duc­tion rates limit pop­u­la­tion re­cov­ery in this species, es­pe­cially by the mid-con­ti­nent pop­u­la­tion, which is sub­ject to hunt­ing. Rein­tro­duc­tion of cap­tive-reared birds has been in­stru­men­tal in main­tain­ing pop­u­la­tion size. Pro­tec­tion of wet­land habi­tats is also es­sen­tial for the sur­vival of this species. (Tacha, et al., 1992)

Con­trib­u­tors

Kari Kirschbaum (au­thor, ed­i­tor), An­i­mal Di­ver­sity Web.

Marie S. Har­ris (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

bog

a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

migratory

makes seasonal movements between breeding and wintering grounds

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

young precocial

young are relatively well-developed when born

Ref­er­ences

Pe­ter­son, R. 1980. East­ern Birds; A com­pletely new field guide to all the birds of east­ern and cen­tral North Amer­ica. New York: Houghton Mif­flin Com­pany.

Tacha, T., S. Nes­bitt, P. Vohs. 1992. Sand­hill Crane (Grus canaden­sis). Pp. 1-24 in A Poole, P Stet­ten­heim, F Gill, eds. The Birds of North Amer­ica, Vol. 31. Philadel­phia, PA: The Acad­emy of Nat­ural Sci­ences; Wash­ing­ton, DC: The Amer­i­can Or­nithol­o­gists' Union.