The Sandhill Crane (Grus canadensis) is a species of large crane of North America and extreme northeastern Siberia. The common name of this bird references habitat like that at the Platte River, on the edge of Nebraska's Sandhills on the American Plains. This is the most important stopover area for the nominotypical subspecies, the Lesser Sandhill Crane (Grus canadensis canadensis), with up to 450,000 of these birds migrating through annually.
Adult is gray overall; during breeding, the plumage is usually much worn and stained, particular in the migratory populations, and looks nearly ochre. The average weight of the larger male 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 15 lb) across the subspecies. The Sandhill Crane has a red forehead, white cheeks and a long dark pointed bill. Its long dark legs trail behind in flight, and the long neck is kept straight in flight. Immature birds have reddish brown upperparts and gray underparts. The sexes look alike. Size varies among the different subspecies; the average height of these birds is around 80 to 120 cm (2.6 to 3.9 ft). The standard linear measurements of the Sandhill are: the wing chord measures 41.8–60 cm (16.5–24 in), the tail is 10–26.4 cm (3.9–10.4 in), the exposed culmen is 6.9–16 cm (2.7–6.3 in) long and the tarsus measures 15.5–26.6 cm (6.1–10.5 in).
This crane frequently gives a loud trumpeting call that suggests a French-style "r" rolled 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 single call of the male.
The Sandhill Crane's large wingspan, typically 1.65 to 2.1 m (5.4 to 6.9 ft), makes this a very skilled soaring bird similar in style to hawks and eagles. Utilizing thermals to obtain lift, they can stay aloft for many hours, requiring only occasional flapping of their wings and consequently expending little energy. With migratory flocks containing hundreds of birds, they can create clear outlines of the normally invisible rising columns of air (thermals) that they ride.
Sandhill Cranes fly south for the winter. In their wintering areas they form flocks of over 10,000 birds. One place to observe this is at Bosque del Apache National Wildlife Refuge, 100 mi (160 km)south of Albuquerque, New Mexico. There is an annual Sandhill Crane Festival in November.
Sandhill cranes are fairly social birds that are usually encountered in pairs or family groups through the year. During migration and winter, non-related cranes come together to form "survival groups" which forage and roost together. Such groups often congregate at migration and winter sites, sometimes resulting in thousands of cranes being found together.
Sandhill Cranes maintain a strict diet but are mainly herbivorous, often eating various types of food based on availability. They often feed with their bills down to the ground as they root around for seeds and other foods in shallow wetlands with vegetation or various upland habitats. Cultivated foods such as corn, wheat and sorghum are readily eaten and may support large numbers of cranes. For example, waste corn is useful to the cranes in preparing for their migrations, providing them with nutrients for the long journey.Among northern races of Sandhill cranes, the diet is most varied especially among breeding birds. Northern cranes and their offspring may variously feed on berries, small mammals, insects, snails, reptiles and amphibians.
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 (though 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. 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. Sandhill Cranes that reach independence are expected to live around 7 years. Sandhill Cranes can live to at least 21 years of age.
As a conspicuous and ground-dwelling species, Sandhill Cranes may face a variety of predators. Mammalian predators such as foxes, raccoons, coyotes, wolves, bobcats and lynxes readily predate cranes of any age, although they are a greater threat to young cranes. Birds that may predate young cranes or crane nests include corvids such as ravens and crows and smaller raptors, including hawks. Cranes of all ages may be predated by eagles, large owls and even Peregrine Falcons. Sandhill Cranes often vigorously defend themselves from predators, especially when defending offspring which are not able to avoid ambushes as easily as their parents. When attacking potential avian predators they fly up at the predator and kick with their feet. When facing mammalian predators, they move toward the predator with their wings open and their bill pointed towards it. If the predator persists, the often hissing crane will attack, stabbing with their bill (which is powerful enough to pierce the skull of a small carnivore) and kicking with their feet.
Lake Alfred, Florida
