Why are there so many sandhill cranes in Wisconsin right now?

Many people were amazed and pleasantly surprised to see thousands of sandhill cranes gathered near the Wisconsin River in Baraboo this past weekend, Nov. 11-12.

The area's protective wetlands and nearby cornfields provide the perfect place for crane populations from across the Midwest to prepare, or begin the process of "staging," to migrate south for the winter.

This mass gathering of sandhills coincided with the International Crane Foundation's second annual Great Midwest Crane Fest in Baraboo, meaning lots of crane enthusiasts got to see the tall, long-necked birds.

Anne Lacy is the director of the International Crane Foundation's Eastern Flyways Program in North America. We spoke with her about sandhills, their migration patterns and where the best places are to see them in Wisconsin before they fly south.

Here's what we learned.

Why are there so many sandhill cranes in Wisconsin right now?

While sandhill cranes spend the warm months in places across the Midwest such as Minnesota, Michigan and all over Wisconsin, there are only a few spots that have big enough bodies of water and enough nearby food for cranes to gather and prepare for migration, Lacy explained.

One of these areas is on the banks of the Wisconsin River in Baraboo. The shallow, wide water body has lots of sandbars. This gives cranes a place to safely roost overnight, because they cannot sleep perched up in trees like many other bird species.

Nearby cornfields also provide the cranes with a large food supply in which to forage and gather the necessary carbohydrates to store as energy for long migration flights, Lacy said.

What are sandhill cranes?

Sandhill cranes are tall, long-necked water birds that nest in wetlands and breed and forage in prairies and grasslands.

Standing up to 4-feet-tall and weighing as much as 11 pounds, sandhills are one of the biggest bird species in Wisconsin. The species can live as long as 30-to-40 years and matures at about three years old, Lacy said.

What states do sandhill cranes live in?

Sandhill cranes breed and spend the warmer months across the northern United States, ranging from Alaska and Canada to New York and Maine, according to Cornell University's "All About Birds" database.

Key staging areas for migrating birds, like the Wisconsin River in Baraboo, are in southern Canada and the midwestern United States. Some crane populations stay put in warmer, year-round habitats in places like Florida and Cuba.

Sandhill cranes in Wisconsin are part of the "Eastern Population," which also includes birds from southern Minnesota, Michigan, Ontario and other places in the Midwest, Lacy said. Sandhills can be found in all 72 Wisconsin counties, though some counties are more suited to large populations than others.

You can even find cranes "in metropolitan areas like Milwaukee, Racine and Kenosha counties, ... but not in the densities we find in east central Wisconsin, where there's a lot of wetlands and agriculture surrounding them," Lacy said.

The largest Wisconsin crane populations, she added, are believed to be in Dodge, Green Lake and Marquette counties.

How many sandhill cranes live in Wisconsin?

While it's hard to measure exactly how many sandhills call Wisconsin home, Lacy said at least 40,000 live here, and the population continues to grow.

When and where do sandhill cranes migrate?

Eastern Population sandhills generally migrate southeast to escape the snow, Lacy said.

"A lot of our birds from Wisconsin will winter as far north as Indiana, but, when the population was smaller, they would go all the way to Florida and the Gulf Coast," she continued. "Some still do, but a lot winter in Indiana, Alabama or Tennessee."

The cranes usually begin staging for migration shortly after Halloween, but they often don't fly south until December. They are a pretty "hearty" species and can keep warm, Lacy said, so they'll stay north so long as they have access to two things ― safe, wetland roosting areas and open fields in which to find food. However, the species is not fond of snow.

"If we have a snow event, the birds will wait for the next day that has appropriate migration conditions and leave," Lacy explained. "So, that'd be ... a sunny day with north winds. They will take that cue and fly south."

Once south, the cranes make sure they stay healthy and safe in order to breed when they're back north in March and April. Crane breeding pairs generally mate for life, and many of those connections are made while in their wintering grounds, Lacy said.

Where are the best places to see sandhill cranes in Wisconsin?

Here are three of the best spots in Wisconsin to see sandhill cranes, according to Lacy:

• Richard Bong State Recreation Area: 26313 Burlington Road, Kansasville. About 40 miles south of Milwaukee.
• Horicon Marsh National Wildlife Refuge: Dodgeville. About 65 miles northwest of Milwaukee.
• Crex Meadows Wildlife Area: 102 E. Crex Ave., Grantsburg. About 360 miles northwest of Milwaukee.

The International Crane Foundation also has a "Sandhill Crane Finder" tool that allows birdwatchers to see an updated map of where crane populations can be found near their area.

Are sandhill cranes endangered?

No, sandhill cranes are not currently endangered, although they used to be. However, North America's other crane species, the whooping crane, is endangered. Only about 80-to-85 whooping cranes currently live in Wisconsin, Lacy said.

Sandhill cranes were "nearly extirpated from the state of Wisconsin" in the early 1900s, Lacy said. This means, although there were sandhill populations in other areas of the country, the Upper Midwest population was almost wiped out.

So, what saved the cranes?

"It was a combination of Wisconsin having good wetland protections, the Migratory Bird Act that was established nationwide in the early 1900s that stopped market hunting and subsistence hunting ... and then the birds themselves; they're generalists, so they can eat a lot of food items," Lacy explained. "They had these protected wetlands to breed in, and in these core areas, (populations) were able to expand out."

Lacy said sandhill populations had largely recovered by the 1990s and 2000s, and started to climb, a testament to "how tough this species is."

Is it true that people used planes to help cranes migrate?

Yes, this happened. In fact, the Milwaukee Journal Sentinel reported on it in the early 2000s. However, these were not sandhills but rather much rarer whooping cranes.

In the federal government's quest to protect whooping cranes from extinction, they decided to introduce a population of whooping cranes from the center of North America that nest in Canada and winter in Texas to Wisconsin, Lacy said. After seeing sandhills cranes' success in Wisconsin, they hoped this whooping crane population would breed in Wisconsin and mirror the sandhills' migration patterns.

"But, without older whooping cranes here to teach them that migration route, they needed some other way, so, beginning in 2001, they used an ultralight plane; it was a group called Operation Migration," Lacy said. "They used the planes to teach the young birds to fly, so then they would continue to do the route on their own."

Now, enough whooping cranes know the route that they teach it to younger birds, who are raised in captivity and then introduced into the Wisconsin whooping crane population. Planes are no longer used to direct crane migration in Wisconsin; the last one flew in 2015.