Environmental News

Thrills on the wing: Sandhill cranes fill the skies at a Minnesota wildlife refuge

Cranes fly through the air and a bald eagle sits in a tree
Migrating sandhill cranes fly above the Sherburne National Wildlife Refuge near Zimmerman, Minn., shortly after sunrise on Nov. 13.
Ben Hovland | MPR News

Every fall, thousands of migrating sandhill cranes stop to rest at the Sherburne National Wildlife Refuge northwest of the Twin Cities before heading south for the winter. The long-legged birds are known for their loud, rattling call.

The number of cranes at the refuge has been climbing in recent years — signs of a remarkable recovery from a century ago, when they nearly vanished from Minnesota due to habitat loss and overhunting.

As the population of eastern sandhill cranes at the Sherburne refuge has swelled, public interest in them has grown as well. During the peak fall months, staff and volunteers conduct weekly crane counts to keep tabs on how many of the lanky birds are congregating at the refuge. 

“People love to know about the cranes, and they want to know what they’re doing,” said Kris Spaeth, a wildlife biologist for the U.S. Fish and Wildlife Service, who oversees the counts. “It was also a way for our staff to monitor it and try to keep track.”

Three people stand in a garage
Volunteer crane counters Bruce Galer, Steve Winslow and Rob Bullis meet in the Sherburne National Wildlife Refuge maintenance garage near before heading out for a count.
Ben Hovland | MPR News

Before one of the season’s final counts earlier this month, volunteers began gathering in the pre-dawn darkness at a maintenance building on the refuge grounds. Clothed in warm layers and blaze-orange hats, each received a clipboard, a pencil and an assigned counting spot from Spaeth.

After instructions, the crane counters fanned out to their designated locations. Spaeth hopped into a pickup and headed down a gravel road to a prime spot overlooking the refuge’s St. Francis Pool, a sprawling wetland complex.

It’s an ideal place for sandhill cranes to rest for the night, often perched on one leg in the chilly water, camouflaged in the cattails and rushes. And the farm fields surrounding the refuge provide a plentiful food source of waste grain leftover from the harvest.

As the sky lightened, the cranes began to take flight — just a few at first, then more and more, wings stretching nearly 7 feet across, lanky legs trailing behind them. Spaeth kept a running tally, peering through binoculars and pausing occasionally to write the totals on her clipboard.

“You learn to count by twos and count by threes and count by eights,” she said. “It puts all of your elementary math skills to use.”

A person writes on a clipboard
U.S. Fish and Wildlife biologist Kris Spaeth counts clusters of migrating sandhill cranes in the Sherburne National Wildlife Refuge.
Ben Hovland | MPR News

The 30,700-acre Sherburne refuge wasn’t always such a popular staging spot for eastern sandhill cranes. In the early 1990s, they numbered around a thousand.

A couple of decades later, their numbers had grown by five or six times, Spaeth said. Two years ago, staff and volunteers counted a record 29,000 cranes in a single day. 

It’s a conservation success story, Spaeth said. Federal protections both for cranes and wetlands contributed to their comeback.

“When you get to see them in big numbers like this, and you think of what it was like for them 100 years ago, it’s really amazing,” she said. “These birds wouldn’t be here if it wasn’t for the actions of a lot of people over the last several decades to conserve habitat that's important to them, and regulate things like hunting.”

Land within the Sherburne refuge has been federally protected since 1965. The Fish and Wildlife Service has restored many wetlands that provide important roosting sites for the cranes, Spaeth said. 

“It’s a reliable spot too,” she said. “There’s no land-use change that’s going on inside of the refuge. So I guess word has gotten out.”

Despite their recovery, sandhill cranes still face threats, mostly human caused. They include habitat loss, wetlands drained for farming or development, collisions with power lines or wind turbines and pesticides in agricultural fields where they forage.

A woman looks at flying cranes through a pair of binoculars
U.S. Fish and Wildlife biologist Kris Spaeth counts migrating sandhill cranes as they fly over the Sherburne National Wildlife Refuge.
Ben Hovland | MPR News

Also, climate change is making it less predictable when the cranes will arrive and how long they'll stay. Typically, the cranes arrive in late August or early September and peak by mid-November, when they head south. This year, the warm autumn delayed the peak by several weeks.

Spaeth said climate change also has shifted the center of their wintering grounds, as temperatures and available food allow the birds to stay farther north for longer.

“That used to be somewhere around Florida and Georgia,” she said. “Then it moved to northern Georgia, and now it’s up into Kentucky even.”

As the number of sandhill cranes at the Sherburne refuge has grown, they've attracted more attention and visitors, hoping to glimpse the distinctive birds and to hear their full-throated call.

“They’re so different than anything else,” said Steve Winslow of Elk River, a longtime refuge volunteer who helped count cranes for the first time this year. “I always think when they fly over, their sound is prehistoric. It sounds like dinosaurs or something.”

Cranes fly through the air
Sandhill cranes fly above the Sherburne National Wildlife Refuge shortly after sunrise.
Ben Hovland | MPR News

As a bird lover, Winslow said the sandhill cranes’ comeback has been amazing to watch. Like bald eagles and wild turkeys, sandhill cranes are one of big success stories in the birding world, he said.

“Fifteen, 20 years ago, there weren’t that many sandhill cranes in Minnesota, especially here on the refuge,” Winslow said. “Now there’s so many of them … there isn’t a day I can go out and not see a crane around this area.”

When the count was over, the staff and volunteers added up their numbers. The official Nov. 13 total was 17,736, roughly 250 short of last year’s peak. On Tuesday, the team tallied even more — a total of 22,197. They plan to do another count next Monday.

Then, as colder temperatures set in, these graceful birds will take to the skies, headed for warmer climes.