Sandhill Cranes are among the largest birds in North America, recognizable by their long legs, gray plumage, and the bright red patch on their foreheads. They are highly social and known for their elaborate, energetic mating dances. Cranes are long-lived and often maintain the same mate for many years, which influences their reproductive strategy. Their reproductive cycle is characterized by a specific, small clutch size and extended parental care.
The Typical Sandhill Crane Clutch Size
The vast majority of breeding Sandhill Crane pairs produce a clutch of two eggs. While one egg is occasionally laid, and three eggs are very rare, the average clutch size across populations is approximately 1.9 eggs. This low number reflects a species that invests heavily in parental care over a long period. This consistency is maintained across all subspecies, including the smaller Lesser and larger Greater Sandhill Cranes.
The two-egg clutch is considered the optimal reproductive output, even though only one chick, often called a colt, typically survives to fledging. The second egg serves as an insurance policy against the failure of the first egg due to infertility, damage, or early chick mortality. Parents generally struggle to successfully raise more than one young due to the high energy demands of chick-rearing. This intensive parental care includes feeding and protecting the offspring for nearly a year.
Nesting Season and Habitat Selection
The timing of the nesting season depends on the specific population. Migratory cranes typically begin nesting in early spring, with egg-laying starting in April or May after they arrive at their northern breeding grounds. Non-migratory populations, such as those in Florida, have a more extended nesting period that can last from January through August.
Sandhill Cranes select secluded, well-protected areas for their nests, usually focusing on wetlands, marshes, or wet meadows. Shallow water is preferred as it offers a natural barrier against terrestrial predators. The pair builds the nest structure on the ground, often in a small depression or slightly elevated site.
The nest is a substantial mound constructed from local vegetation, such as reeds, grasses, and sticks. Both the male and female participate in gathering the material and building the structure, which can measure up to two feet in diameter. This bulky platform is designed to keep the eggs dry and slightly above the water level in their marshy habitat.
The Incubation and Hatching Process
Incubation lasts for approximately 29 to 32 days. The female typically lays the two eggs a day or two apart and begins incubating immediately after the first egg is laid. Both members of the breeding pair share the duty of sitting on the nest. However, the female often takes the majority of the incubation time, including most of the nighttime hours.
Because incubation starts with the first egg, the eggs hatch asynchronously, meaning one colt emerges a day or two before its sibling. The newly hatched chicks are precocial, meaning they are covered in down feathers, have open eyes, and are highly active. This advanced state allows the young to leave the nest within 24 hours of hatching.
The colts are intensely cared for by both adults and are able to walk and follow their parents almost immediately. The parents feed and brood the young for several weeks, providing warmth and protection. This extended biparental care continues for nine to ten months. The young accompany their parents during the fall migration before achieving independence the following spring.