Sandhill Cranes are a prominent part of Wisconsin’s wildlife, recognized by their distinctive appearance and vocalizations. These large birds, often standing up to five feet tall, possess a gray body, long legs and neck, and a striking red patch on their forehead. Their presence is frequently announced by a loud, rattling bugle call that can carry for miles, a sound unique to them. Wisconsin is home to the Greater Sandhill Crane, a subspecies. These cranes are a familiar sight across Wisconsin’s varied landscapes, from wetlands to agricultural fields.
Autumn Departure from Wisconsin
Sandhill Cranes typically begin their autumn departure from Wisconsin as early as September, with peak migration throughout October and extending into mid-November. Before their southward journey, these birds gather in large numbers at designated staging areas across the state. Notable locations include Crex Meadows, White River Marsh, Necedah National Wildlife Refuge, and sections along the Wisconsin River. At these sites, thousands of cranes can be observed feeding in recently harvested cornfields, accumulating energy reserves for their flight.
Their final departure often aligns with colder temperatures and strong mid-November winds. These winds assist the cranes as they ascend, sometimes reaching altitudes of up to 5,000 feet, to catch favorable air currents. The majority of Wisconsin’s Sandhill Cranes migrate to wintering grounds, primarily in Florida. Some flocks may make stopovers in states like Indiana, using areas such as the Jasper-Pulaski Fish & Wildlife Area before continuing south.
Spring Return to Wisconsin
Sandhill Cranes typically begin their return to Wisconsin in March, though some early arrivals are seen in mid-February. This northward migration is driven by their need to breed and nest within the state’s suitable habitats. Upon their return, cranes begin establishing territories and constructing nests, with egg-laying generally occurring in April and May.
Nests are often built in wetlands, using materials like grasses and sedges, sometimes on floating bog mats or near open water. These wetland locations provide safety from predators for their eggs and young. Areas in central and southern Wisconsin, characterized by abundant wetlands, exhibit some of the highest nesting densities for Sandhill Cranes. The return and nesting of these birds contribute to the growing Sandhill Crane population.
Key Influences on Migration Timing
Several environmental and biological factors determine the timing of Sandhill Crane migration. A primary environmental cue for autumn departure is the decreasing length of daylight hours, known as photoperiod. This change signals winter’s approach and triggers their migratory preparations. Dropping air temperatures and the onset of cold winds further prompt their southward movement.
The availability of food sources also plays a role in their departure decisions. Cranes rely on abundant food, particularly leftover grains in harvested agricultural fields, to build fat reserves for migration. Conversely, for spring migration, rising temperatures and the thawing of water bodies are important, as cranes need open water for roosting and access to foraging areas. While environmental conditions provide immediate triggers, migratory behavior is rooted in instinct and genetic programming.