Sandhill Cranes heading back to the Artic
Mid March and the Sandhill Cranes leave Arizona for the artic north.
Sandhill cranes are fairly social birds that usually live 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 in the thousands.
Sandhill cranes are mainly herbivorous, but eat various types of food, depending 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. Cranes readily eat cultivated foods such as corn, wheat and sorghum. Waste corn is useful to cranes preparing for migration, providing them with nutrients for the long journey. Among northern races of sandhill cranes, the diet is most varied, especially among breeding birds. They variously feed on berries, small mammals, insects, snails, reptiles and amphibians.
Sandhill cranes raise one brood per year. In non-migratory populations, laying begins between December and August. In migratory populations, laying usually begins in April or May. Both members of a breeding pair build the nest using plant material from the surrounding area. Nest sites are usually marshes, bogs or swales, though occasionally on dry land. Females lay one to three (usually two) oval, dull brown eggs with reddish markings. Both parents incubate the eggs for about 30 days. The chicks are precocial; they hatch covered in down, with their eyes open and able to leave the nest within a day. The parents brood the chicks for up to three weeks after hatching, feeding them intensively for the first few weeks, then gradually less frequently until they reach independence at nine or ten months old.
The chicks remain with their parents until one or two months before the parents lay the next clutch of eggs. After leaving their parents, the chicks form nomadic flocks with other juveniles and non-breeders. They remain in these flocks until they form breeding pairs at between two and seven years old.
As a conspicuous ground-dwelling species, sandhill cranes are at risk from predators, which are probably the main non-anthropogenic source of mortality. Mammals like foxes, raccoons, coyotes, wolves, cougars, bobcats and lynx hunt them given any opportunity, the first three mainly hunting large numbers of young cranes, the latter four types more rarely taking full-grown cranes in ambush excepting the prolific bobcat. Corvids, such as ravens and crows, gulls and smaller raptors like hawks (largely northern harriers or red-tailed hawks) feed on young cranes and eggs. Cranes of all ages are hunted by both North American species of eagles. Mainly chicks and possibly a few adults may be predated by great horned owls and even the much smaller peregrine falcons has successfully killed a 3.1 kg (6.8 lb) adult sandhill crane in a stoop. In Oregon and California, the most serious predators of flighted juveniles and adults has been cited as golden eagles and bobcats, the most serious predators of chicks are reportedly coyotes, ravens, raccoons, American mink and great horned owls in rough descending order. In the Cuban and Florida sandhill crane populations, the American crocodile and alligator can take a surprisingly large number of cranes, especially recent fledglings. Sandhill cranes defend themselves and their young from aerial predators by jumping and kicking. Actively brooding adults are more likely to react aggressively to potential predators in order to defend their chicks than wintering birds, which most often will normally try to evade attacks on foot or in flight.For land predators, they move forward, often hissing, with their wings open and bill pointed. If the predator persists, the crane stabs with its bill (which is powerful enough to pierce the skull of a small carnivore) and kicks.