The return of the cranes

MIKE POLKOWSKE photo

^{By ELIZABETH LADEN}

ISLAND PARK — Sandhill cranes have returned to their mating and nesting grounds. They raucous, gravelly calls echo across the caldera. They came here in large flocks from wintering grounds in Texas, Utah, Mexico, and California. Soon after arrival, they split up into pairs established as recently as last fall and as many as 20 years ago — they mate for life.

Most return to the same places they nested in the past.

Our cabin, between two creeks in Shotgun, is right in the middle of a nesting area, and we can spot these big birds flying back and forth and venturing out into the meadows to dance and search for insects.

Sandhills are the most common of all the world's cranes, and are found mainly in North America. They also range south to Mexico and Cuba, and as far west as Siberia. They’ve existed on Earth for centuries, and seeing one is glimpsing into ancient times —a skeletal fossil found in what is now Nebraska is from the Miocene Epoch, which was around 10 million years ago. The fossilized skeleton is structurally the same as that of the modern sandhill crane, making the crane the oldest known surviving bird species.

Sandhills live in freshwater wetlands bordering open meadows and forests. They eat plants, wild and cultured grains, mice, frogs, snakes, insects, and worms. They dig in the soil for tubers from spring beauty bulbs to glacier lily bulbs to potatoes, and can cause significant crop damage in agricultural areas.

The adult crane’s body and wing feathers are gray and their heads are topped with a bright red crown. Adults stand almost 3 feet tall and have a wingspan of 6 feet or more. Immature birds are mottled with rusty feathers and do not have a red forehead. Adult plumage does not grow in for two and a half years.

The breeding adults are noisiest now during the mating ritual, when pairs are engaged in what is known as "unison calling." They throw their heads back and unleash a stream of songs and rattles, turning their heads back and forth . This throws their voices into many different directions, which makes it tricky to know exactly where the sounds are coming from. Their windpipes form a loop within the breastbone, which makes their calls so resonant.

Crane dance moves include deep bowing, running, hopping from side to side, one leg at a time, and leaping high in the air. They will also dip their beaks into mud and coat their breasts and backs with the sticky dark stuff. They display all these behaviors year round, but most dramatically now, while they are getting in the mating mood. People in the caldera now will hear and see crane sounds and moves that few people ever see. By the time the summer people arrive, the height of the mating period will be over and the cranes will be tending their nests.

Females normally lay two spotted, graybrown eggs in a nest of dried grass, sticks, feathers, and stones built on the ground. Both parents incubate the eggs, and males do the most work to keep predators away from the nest. The young hatch in about 30 days and are able to walk immediately. Their parents feed them, but the young birds also capture insects on their own. By the time they’re two and a half months old, they’re ready to migrate south with their parents.

Cranes are protective of their territories, nests, and nestlings. They do not want people to approach them. Leave them alone, watch from a distance, and use a long lens when photographing them. Their long legs enable them to easily outdistance a walking person, and when you see a crane walking and maintaining an exact distance from you, it is very aware of you and give it space. It is never good to approach a bird sitting on a nest. Cranes have been known to abandon nests with eggs and newly hatched chicks when people infringe on their territories. If you do come upon a nesting crane, you will notice that it has extended its head straight out and is very still. This is a way the crane can blend into the background and not be seen. The other parent may then run up to you and then turn away, pretending to have a broken wing so you think it is weak and easy prey, follow it, and do not find the nest. Other birds also try to deceive predators with a broken wing display, including killdeer.

When they’re ready to head south this fall, the cranes will form flocks and take to the sky in graceful, circling columns, riding thermal currents and forming a “V.” They fly at high altitudes, covering up to 350 miles a day.

Like the busy mating and nesting cranes, folks aren’t thinking about the fall. We’re enjoying every minute of spring and looking forward to a wonderful summer.

This is part of the April 23, 2009 online edition of The Island Park News.

Have an opinion on this matter? We'd like to hear from you. Click here.