Cranes return to winter home (Sandhill, that is)

[Donna]

BOSQUE DEL APACHE NATIONAL WILDLIFE REFUGE, N.M. - The full-throated call of returning sandhill cranes in the golden light of a fall afternoon brought a smile to Colin Lee's face.

"It's nice to see the seasons change here," said the 36-year-old Lee, a wildlife biologist with the U.S. Fish and Wildlife Service. He watched the big birds pick through stubble in a field near the north end of the sprawling Bosque del Apache National Wildlife Refuge.

The 57,191-acre refuge on the Rio Grande south of Socorro sees some 350 different species of birds a year, plus reptiles, amphibians, insects and 30-odd kinds of mammals.

But the cranes, big charismatic birds that winter here by the thousands, are the marquee attraction.

Every year, Friends of the Bosque, a nonprofit that supports the refuge, holds a Festival of the Cranes to celebrate the birds' arrival, with talks, tours and hikes.

Taller than a typical kindergartner, tens of thousands of the birds spend winters along the Middle Rio Grande in central New Mexico at Bosque del Apache and the nearby Bernardo Waterfowl Area, maintained by the New Mexico Department of Game and Fish.

At dusk one recent evening, Lee took out his binoculars and counted with care at a Bosque del Apache pond, filled with water to create a safe evening place to roost.

By sundown, Lee estimated 700 birds. A small crowd of humans also gathered with cameras and long lenses to watch the show. More birds flew in - family groups of three or four at a time, their long legs dangling as they settled into the shallow water.

The central New Mexico flock represents a long-term success in helping a species once threatened by habitat destruction. Refuge officials estimate fewer than two dozen sandhill cranes wintered at the Bosque del Apache in 1941.

Created in the 1930s by the U.S. government to address the problem, the wildlife refuge is now home to more than 10,000 birds each winter.

Refuge officials work with local farmers to grow corn for the birds on some of the land. Large flat areas, bordered with dikes, are periodically filled with shallow water and then drained to mimic the seasonal wetlands once created by a wild Rio Grande.

Huge flocks of snow geese and Ross' geese, also by the tens of thousands, join the cranes in winter along with smaller birds such as the pintail duck.

While current crane populations are healthy, scientists who study the bird are monitoring signs of problems the big birds and other similar waterfowl may face in the future, said John Vradenburg, the refuge's head biologist.

The birds summer in the northern Rockies, where they nest and raise their young, before making an early fall beeline for New Mexico.

The problem, Vradenburg said, is the loss of key habitat along the flyway.

The birds make the trip in several hops, stopping to eat for several days to fuel up "kind of like us eating at McDonald's on the road," Vradenburg explained.

But development along the flyway, including the San Luis Valley in Colorado, is reducing available food for the trip, Vradenburg said.

The problem is less severe for cranes than other waterfowl because they aren't terribly picky about what they eat. Vradenburg said other waterfowl, birds with more specialized diets like the northern pintail duck, are at greater risk.