Female lays two large eggs in May, having beforehand constructed a large, foot-high nest in an inaccessible marshy areas. The second egg is laid 2 or 3 days after the first, and consequently one chick hatches 2 or 3 days later than the other, 32-34 days after being laid. Being slightly older and stronger, the first chick has a decided advantage over its sibling, and the second chick is often trampled to death or thrown out of the nest. Feeding is done by the both parents and the hatchlings grow quite rapidly. Behavior Partners share in incubation and tending of one or two young.
Pairs establish lifelong bonds, maintained and reinforced by courtship dances and nuptial displays.
Cranes make loud trumpeting calls when courting and during flight, and it is easy to understand why they are easy prey, particularly for man. Rapid growth enables the young to take part, only 4 months after birth, in the long flight to the wintering grounds in Texas, some 2100 miles away. Ideal habitat is grassy plains interspersed with marshes, numerous lakes and ponds. In addition to the slow reproductive rate, causes of the decline in the populations of whooping cranes include diseases and natural hazards such as storms. More importantly, there are now two populations in the wild.