Monday, March 5, 2007

Sandhill cranes in spring

It's almost spring, and that means soon I'll hear the husky voices of sandhill cranes calling to each other - "Khrrrr! khrrrr! khrrrr!" - as they ride the winds northward high over our valley. Right now they're gathered, some 20,000 of them, in the marshes and farm fields of the San Luis Valley, one pass south of us in southcentral Colorado, to rest, tank up on food, and socialize during an extended break on their long migration between winter homes in the marshes of the southern Southwest and northern Mexico, and nesting habitat in beaver ponds and wet meadows as far north as the Arctic Circle.

One spring morning, my husband Richard and I loaded our photographer friend Glenn and his case of camera gear into the van, along with our Great Dane, Isis, and left the house in the darkness before dawn, bound for the San Luis Valley to see sandhill cranes.

By the time we reached Monte Vista, it was light. We turned off the road at the marsh where we expected to see flocks of murmuring cranes - and found none. We went to another marsh, and struck out there too. Finally we rolled down the window and listened. From off to the west came the distant swell of crane voices; we drove in that direction, tracking the sound on the chill air pouring in the open windows. Down a dusty dirt two-track, past a clump of still-winter-bare cottonwoods, and there they were.

Hundreds of gray-feathered, red-capped bodies clumped in the stubble of a cornfield, probing the soil, pairing up to leap into the air and dance, jostling each other, lifting long beaks to the ever-lighter sky, and all the while, calling in those throaty voices.

There were tall cranes and shorter cranes, grayer cranes and dusty brown cranes. The gray birds were adults; the brownish ones last year’s young, still carrying their juvenile plumage. The taller birds are a separate subspecies, greater sandhill cranes. They are aptly named: at four feet tall, with wings that stretch as much as seven and a half feet from tip to tip, and weights of up to ten pounds, they almost tower over the smaller subspecies and weigh thirty percent more than those birds.

As Glenn’s camera shutter clicked rapid-fire, a solid ribbon of “Khrrrr, khrrrr, khrrrr!” crane voices rolled over us, a call often described as “bugling,” though it lacks the brassy character of that instrument. It’s a husky and seductive sound, haunting and melodic, that can carry for miles. Now and then the nasal “Krek!” of a young bird punctuated the flow, like an adolescent whose voice is breaking.

Most of the cranes in the mass of birds were feeding intently, pacing through the stubble with measured tread, searching for food. Their long necks dipped in a steady up-down rhythm as their spear-like beaks probed the soil for waste grain and insect larvae.

As the sun came over the horizon, a pair began courting just a few feet away. One bird leaped into the air on long legs, wings spread wide, then landed, legs bent in a bowing motion. The other leapt up too, then bowed; the two stretched necks upward in unison and crossed beaks in a graceful silhouette as if posing.

At night, the tall birds gather in the safety of valley marshes; by day, they fly out to feed in nearby farm fields and wet meadows. As the days grow longer and warmer, the cranes become restless. They take flight at the slightest disturbance, leaping into the air with their long legs and lifting off on wide wings, then circling and setting down again, all the while calling.

As the sun sank below the horizon on that spring day, the sandhill cranes we had been watching began to lift off by the tens and fifties, rising on outstretched wings into the sky, circling higher and higher. Group after group of the huge birds lifted off, spiraled to gain altitude, and then headed north, disappearing into the dusk, until all that remained was the echo of those throaty calls, “Khrrrr, khrrrr, khrrrr!”

I'm talking about sandhill cranes and the valley they call home in spring and fall at the Monte Vista Crane Festival in southern Colorado, this Friday, March 9th at 7 p.m. My talk is sponsored by the Crane Festival and Arkansas Valley Audubon Society. Join us!

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