Sandhill Cranes

512x219_Sandhill Crane-1743_John Olson

Around the world, crane species are featured in cultures through paintings, fabrics, and dances. Their powerful calls and elaborate dances have captivated audiences globally, including sandhill cranes at Bosque del Apache National Wildlife Refuge. 

Sandhill cranes typically begin to arrive in central New Mexico and at Bosque del Apache National Wildlife Refuge in late October and stay through mid February. Family groups migrate together, with juvenile birds typically staying with their parents through their first winter. Flocks congregate in open fields to feed during the day and roost in shallow water at night for safety. Variations in size and color between birds may be for a number of reasons.

By the time the family groups migrate to central New Mexico, juvenile sandhill cranes are the same size as (or sometimes slightly larger than) their parents. Instead of a red forehead, juvenile sandhill cranes have a brownish crown until January. 

Though a “typical” adult sandhill crane has gray feathers, the feathers of some birds appear rust-colored. This is staining that occurs when the bird preens its feathers with iron-rich soil found on their breeding grounds and is thought to help camouflage the bird from predators.

In a large flock of sandhill cranes in central New Mexico, there may be groups of noticeably smaller birds. The lesser sandhill crane nests in northern Canada, Alaska, and Siberia. This sub-population of sandhill cranes is about 30% smaller than the greater sandhill crane, which nest in and migrate from the northern Rocky Mountains. Other sub-populations of sandhill cranes are present in other parts of North America.

Historically, the Rio Grande created seasonal wetlands that grew nutritious grains and other seeds which provided food for a variety of animal species, including migrating sandhill cranes. The wild river created such habitat through a large stretch of central and southern New Mexico. As the wild Rio Grande was tamed with dams and channelizing, this habitat disappeared and only a few dozen sandhill cranes wintered in the area that is now Bosque del Apache National Wildlife Refuge. 

Today, the refuge staff at Bosque del Apache manages river water to recreate wetlands like when the river ran wild. Additionally, grain crops such as corn and triticale are grown to meet the nutritional needs of the large flocks of sandhill cranes, geese, and ducks who migrate to central New Mexico each winter. Agricultural fields are planted on a rotation to allow soils to recover nutrients. Location of fields is considered to discourage the spread of disease and to encourage the birds to spread out. Learn more about resource management at Bosque del Apache.

Sandhill cranes typically do not enter standing corn as predators may be lurking unseen. To provide enough food for the entire winter season for overwintering birds, including sandhill cranes, corn is knocked over by refuge staff with farm equipment to provide access to the calorie-rich food. This practice also discourages predation on other crops grown in the valley not intended for sandhill cranes (such as chilies).

These management practices benefit other wildlife, too! Skunks, elk, blackbirds, geese, javelina, and coyote are just a few of the other species that have been observed in agricultural fields feeding, loafing, or resting. 

While observing sandhill cranes, consider their journey to Bosque del Apache National Wildlife Refuge and back to their summer habitat. How is their journey similar to yours?