The sandhill crane (Antigone canadensis) is a species of large crane of North America and extreme northeastern Siberia. The common name of this bird refers to its habitat, such as the Platte River, on the edge of Nebraska's Sandhills on the American Great Plains. Sandhill cranes are known to frequent the edges of bodies of water. The central Platte River Valley in Nebraska is the most important stopover area for the nominotypical subspecies, the lesser sandhill crane (A. c. canadensis), with up to 450,000 of these birds migrating through annually.
Taxonomy In 1750, British naturalist George Edwards included an illustration and a description of the sandhill crane in the third volume of his A Natural History of Uncommon Birds, referring to the species as the 'Brown and Ash-colour'd Crane'. Edwards based his hand-colored etching on a preserved specimen that had been brought to London from the Hudson Bay area of Canada by James Isham. When in 1758, Swedish naturalist Carl Linnaeus updated his Systema Naturae for the 10th edition, he placed the sandhill crane with herons and cranes in the genus Ardea. Linnaeus included a brief description, coined the binomial name Ardea canadensis, and cited Edwards' work. The sandhill crane was formerly placed in the genus Grus, but a molecular phylogenetic study published in 2010 found that the genus, as then defined, was polyphyletic. In the resulting rearrangement to create monophyletic genera, four species, including the sandhill crane, were placed in the resurrected genus Antigone that had originally been erected by German naturalist Ludwig Reichenbach in 1853. The specific epithet canadensis is the modern Latin word for "from Canada". Five subspecies are recognised:
A. c. canadensis (Linnaeus, 1758) – northeast Siberia through Alaska and northern Canada to Baffin Island A. c. nesiotes (Bangs & Zappey, 1905) – Cuba and Isla de la Juventud (Isle of Pines) A. c. pratensis (Meyer, FAA, 1794) – Georgia and Florida A. c. pulla (Aldrich, 1972) – Mississippi A. c. tabida (Peters, JL, 1925) – southern Canada and west-central United States A 2025 study showed a deep genetic divide between the sandhill crane populations, with geographic barriers resulting in minimal gene flow between inland and coastal populations. The inland and coastal populations of sandhill cranes show consistent morphological differences in size, colour, and facial structure that can be observed in field conditions. The two populations also differ in behavior and preferred habitat. The authors of the study argue that the diversity within the species must be better reflected in conservation efforts in order to protect vulnerable populations.
Description Adults are gray overall; during breeding, their plumage is usually much worn and stained, particularly in the migratory populations, and looks nearly ochre. The average weight of the larger males is 4.57 kg (10.1 lb), while the average weight of females is 4.02 kg (8.9 lb), with a range of 2.7 to 6.7 kg (6.0 to 14.8 lb) across the subspecies. Sandhill cranes have red foreheads, white cheeks, and long, dark, pointed bills. In flight, their long, dark legs trail behind, and their long necks keep straight. Immature birds have reddish-brown upper parts and gray underparts. The juveniles do not have the characteristic red foreheads, making distinguishing the young from the parents possible, even when they are the same height. The sexes look alike. Sizes vary among the different subspecies; the typical height of these birds is around 80 to 136 cm (2 ft 7 in to 4 ft 6 in). Their wing chords are typically 41.8–60.0 cm (16.5–23.6 in), tails are 10.0–26.4 cm (3.9–10.4 in), the exposed culmens are 6.9–16 cm (2.7–6.3 in) long, and the tarsi measure 15.5–26.6 cm (6.1–10.5 in). Wingspan is 200 cm (78.7 in). These cranes frequently give a loud, trumpeting call that suggests a rolled "r" in the throat, and they can be heard from a long distance. Mated pairs of cranes engage in "unison calling". The cranes stand close together, calling in a synchronized and complex duet. The female makes two calls for every one from the male. Sandhill cranes' large wingspans, typically 1.65 to 2.30 m (5 ft 5 in to 7 ft 7 in), make them very skilled soaring birds, similar in style to hawks and eagles. Using thermals to obtain lift, they can stay aloft for many hours, requiring only occasional flapping of their wings, thus expending little energy. Migratory flocks contain hundreds of birds, and can create clear outlines of the normally invisible rising columns of air (thermals) they ride. Sandhill cranes fly south for the winter. In their wintering areas, they form flocks over 10,000. One place this happens is at Bosque del Apache National Wildlife Refuge, 100 miles (160 km) south of Albuquerque, New Mexico. An annual Sandhill Crane Festival is held there in November.
Fossil record
Sandhill cranes have one of the longest fossil histories of any extant bird. A 10-million-year-old crane fossil from Nebraska is said to be of this species, but this may be from a prehistoric relative or ancestor of sandhill cranes, of a genus other than Grus and Antigone. The oldest unequivocal sandhill crane fossil is 2.5 million years old, older by half than the earliest remains of most living species of birds, primarily found from after the Pliocene/Pleistocene boundary some 1.8 million years ago. As these ancient sandhill cranes varied as much in size as present-day birds, those Pliocene fossils are sometimes described as new species. Grus haydeni may have been a prehistoric relative, or it may comprise material of a sandhill crane and its ancestor.
Subspecies and evolution
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