Sure, He’s Retired, but This Conservation Legend Isn’t Slowing Down

Carrol Henderson rescued Minnesota’s Peregrine Falcons and Trumpeter Swans. Can he save this heron rookery before it’s too late?

On a warm day in late May, sunbeams peek through a thick canopy of aspen, oak, and black cherry near Rochester, Minnesota. Here and there, these natural spotlights fall on Carrol Henderson, clad in khaki cargo pants, plaid button-up, and baseball cap, a camera slung around his neck as usual. Through thin-rimmed glasses and binoculars, his blue eyes scan the high branches for the delicate nests of Great Blue Herons.

After a decades-long career in conservation, today Henderson is a “Rookie” again. That’s what a group of Rochester homeowners and concerned citizens have dubbed themselves in honor of the unique heron rookery they’re working to save from development. The species typically nests in wet areas like riverbanks and lakeshores, but this roughly 40-nest clan has made a home in the relatively dry woods along diminutive Cascade Creek. “It’s a colony that has achieved a sense of adaptation to the upland forest that no other colony in Minnesota has,” Henderson says.

Walking quietly through the woods, Henderson and Leal Segura, a leader of the Save The Rookery effort, note that many of the trees housing nests have been marked with orange blazes. This is where developers plan to build a winding road through the colony, which has been here for more than three decades. The road will lead toward 10 single-family homes planned for a 30-acre portion of the forest. While the project itself still needs permits, there’s little stopping the landowner from cutting down the trees. The federal Migratory Bird Treaty Act protects the birds during their nesting season, but after that they’re out of luck. Activists worry that as soon as the last of this year’s young fledge—which should happen by the end of August at the latest—chainsaws will wipe out the rookery.

Henderson lives about an hour and a half away, near Minneapolis, but has been intimately involved with the effort since first hearing about it this spring. He has testified on the birds’ behalf at local meetings and helped to brainstorm a multi-pronged approach to save the rookery. Minnesota’s Great Blue Heron numbers have been in steady decline for several decades. “It’s just really unfortunate to see there are some people so profit-driven,” he whispers to Segura so as to not disturb the birds. “They don’t want anything to stand in their way.”

This is about as close to cynicism as the fervently optimistic Henderson gets. In a moment, he’s back to his signature disposition. “In all the years that I’ve worked with these different projects, I’ve never been involved with one that ended up in the destruction of the colony,” he says of previous efforts to save colonies during his career as a conservationist, his lithe gait through the dense woods belying his 75 years. “I don’t want to ruin my record!”

Henderson’s record is long and impressive by any measure. Before his retirement in 2018, he spent 44 years at the Minnesota Department of Natural Resources, most of it as director of the department’s Nongame Wildlife Program since its inception in 1977. Combining broad scientific know-how, media savvy, and an empathetic grasp of human behavior, Henderson has been able to make wildlife allies out of almost anyone. He grew the non-game office from a one-man show with a meager $25,000 annual budget (which included his salary) to an established program that today boasts an annual budget of nearly $3 million and protects thousands of species. Along the way he became widely regarded as a true giant of conservation.

“He was a spark in a state that has almost boundless good will for the environment and wildlife, but that good will needs to be organized, codified, and energized,” says Dennis Anderson, who has covered Henderson’s work extensively as outdoor columnist for the Minneapolis and St. Paul Star Tribune. “He’s done that 100 times over.” Henderson’s legacy will be a Minnesota that’s better for all wildlife, from leopard frogs to river otters, Anderson says. “No one was really speaking for them before.”

But just because Henderson is retired doesn’t mean that legacy is cemented. If anything, he is more active than ever. “It’s more intriguing and challenging,” he says, “now that I can say exactly what I think.” 


enderson owes his love of wildlife in large part to his upbringing on a farm in central Iowa. “I was always finding bird nests,” he says. He became obsessed, “to the point that when my parents or grandparents gave me little bird books, I would just literally wear the covers off.”

He left the farm to go to college at nearby Iowa State University where he majored in zoology and minored in botany and physics. At the suggestion of a professor, he applied to graduate school at the University of Georgia to study ecology and wildlife management. “I grew up mostly not traveling more than 25 miles from home,” Henderson says. “I thought it would probably do me good to go to Georgia and get a little broader perspective on the world.”

Georgia was where he took the classes in journalism, public speaking, and media relations that he largely credits for the success of his conservation work decades later. He also accepted a professor’s offer to study land use and agriculture in Costa Rica, where with a simple bailamos—let’s dance—he met a local who later became his wife, Ethelle. They’ve been married for 51 years.

The duo moved to Minnesota in 1974 for Henderson’s original role with the DNR, assistant manager at the Lac qui Parle Wildlife Management Area. Three years later, the department created a program to protect non-game wildlife—the species that aren’t pursued by hunters and anglers and tend to get overlooked when conservation funding gets divvied up. Henderson was hired as the first and, until his retirement, only person to lead it. His visionary ambitions for the program quickly outgrew its meager funding.

The program’s prospects brightened in 1980, when the Legislature created a line on Minnesota tax forms, now known as the Chickadee Checkoff, allowing residents to donate a portion of their refund to non-game conservation. “Our budget went from about $25,000 per year up to about $500,000 per year,” Henderson says. Since 1981, the checkoff has raised more than $30 million to protect at-risk wildlife.

Suddenly the program, still so new that it had no overarching game plan, was flush with cash. Henderson’s creativity and tenacity were unleashed. “He almost literally built the Minnesota DNR non-game program from scratch. It was his vision,” Anderson says “He thought in terms of ecology and the health of the landscape, and especially in terms of what is not often practiced diligently: the human dimension part of it.”

The first species Henderson focused on recovering was the Peregrine Falcon, whose populations had been plummeting across the U.S. due to a range of human factors, including the introduction of the toxic pesticide DDT in the ‘50s and ‘60s.

In 1981, Henderson launched a partnership with the University of Minnesota Raptor Center and several conservation organizations to return the birds to the state. They worked with more than 40 breeders around the U.S. and Canada to purchase young falcons, the first five of which were released in 1982, followed by three dozen more over the next four years. In 1987, a wild Peregrine fledged in Minnesota for the first time since the ‘60s. Today the state enjoys a self-sustaining population that produces between 120 and 150 chicks each year.

Henderson found similar success in efforts to restore other wildlife species including Bald Eagles, Eastern Bluebirds, and river otters. But it was his work to bring back Trumpeter Swans that meant the most to him.

Long hunted for their pelts, meat, and feathers, just 69 Trumpeter Swans remained in the continental U.S. by 1932, mostly in Montana. Henderson teamed up with a University of Minnesota ornithologist to publish a 1982 proposal for restoring the species.

Because Minnesota was the first state to tackle a major Trumpeter restoration project, Henderson and his collaborators were charting unknown territory. They had to work out how to collect, move, and hatch the eggs, and then how to care for the young chicks before their release. The system they came up with involved gathering eggs from Alaska, transporting them in specialized suitcases warmed with water bottles—they periodically refilled the bottles with hot water from the airplane’s coffee pot—and eventually releasing cygnets into the wild under careful supervision.

Drawing on his graduate coursework in journalism, Henderson convinced ABC News to cover the release of 40 swans in 1988. In April of that year, a news crew traveled from New York to a remote lake on the Minnesota reservation of the White Earth Band of Ojibwe. An estimated 40 million people watched the segment when it aired the following month.

From 1987 to 1994, Henderson oversaw the reintroduction of 217 swans. “Without his ingenuity and bravery, Trumpeter Swans probably still wouldn’t exist in Minnesota,” says Lori Naumann, a spokeswoman for the non-game program who worked in the DNR cafeteria until Henderson hired her in an administrative position in 1989. Today, Minnesota’s population tops 30,000.

One January day a decade after the start of the project, Henderson was perched along the banks of the Mississippi River 40 miles northwest of Minneapolis, scoping out a flock of Trumpeters. Soon one of the swans began to swim towards him. Hoping to put the bird at ease, “I just started a little aimless talk—the weather, whatever,” he says. “He was so close. He stepped up out of the water and I could see his leg band”—number 619-71888. “I got back to the office, looked up the band number, and it turns out I actually collected that swan as an egg in Alaska in 1988,” Henderson says. He had released the swan seven years earlier, over 100 miles away.


ow that Henderson is retired, nobody would blame him if he took things easy. He is a serious birder with a life list of around 3,000 species, and he’s certainly earned the right to enjoy his hobbies. But conservation has never been just a job for Henderson, and there’s still so much to do, from new writing projects to establishing a birding trail in the state’s northern bogs and boreal forest. A top priority, though, is protecting loons and other birds from lead poisoning.

Shortly before he left the DNR, Henderson concluded nearly a decade of research that showed how the 2010 Deepwater Horizon oil spill harmed Common Loons and American White Pelicans that overwinter on the Gulf of Mexico and breed in Minnesota. His findings helped to secure the state over $6 million in funding for loon protection from the federal government’s spill settlement with BP. Officials earmarked $1.2 million of it to encourage anglers to switch from lead fishing tackle to nontoxic alternatives. Loons often ingest lead sinkers while feeding, and the resulting poisoning is responsible for around 14 percent of loon deaths in Minnesota—as many as 200 birds per year.

The effort is only Henderson’s most recent endeavor to prevent lead poisoning of birds. Some of his earliest fieldwork convinced the state to ban lead ammunition for waterfowl hunting in 1987. The federal government followed suit a few years later with a similar nationwide ban that by one estimate saves the lives of around 1.4 million ducks per year. In retirement, Henderson has set his sights on eliminating lead ammunition in deer hunting, which kills eagles and other birds that eat bullet fragments while feeding on carrion.

Most immediately, though, he’s focused on saving the Rochester rookery. Segura called him for advice out of the blue in March when she, her husband, and their neighbors first became aware of development efforts in the woods where they and the Great Blue Herons live. For Segura, the fight is personal: She still lives in the same house where she grew up alongside the colony and became attached to the gangly birds. “But I never realized the qualities that made [the colony] so unique for Minnesota before learning specifics from you,” Segura says to Henderson, who is seated across from her, sipping black coffee.

At Segura’s kitchen table, the duo brainstorms various ways to save the colony—maybe the Rookies could buy the land where the nests are, or form a nonprofit to protect it. “We need to cast a wide net now,” Henderson says. “It could be a classroom education site. Maybe Mayo Clinic,” which is based in Rochester, “would be able to sponsor a webcam or something to give people the chance to see what’s happening.”

Recent weeks have had the Rookies on a see-saw of wins and setbacks. In May, the Olmsted County Commission made the property eligible for development by changing its zoning. But in late June, the group learned that the DNR’s Natural Heritage Advisory Committee voted to consider the site for protection as a designated Scientific and Natural Area, an idea Henderson has championed. Then, on June 29, a judge denied an injunction that Segura and company filed to halt work there.

Now it’s a race to save the rookery before its last chicks fledge and its federal protection runs out. Henderson remains undaunted by the ticking clock. He’ll just keep doing what he’s done all his life: working hard, following his instincts, always looking for the next opportunity to do some good. It’s a straightforward approach, but it’s carried him this far.  

“I get involved with something and then it’s like I just have to channel all my energies into that one cause to keep from getting distracted, to see things through,” Henderson says. “This is the kind of stuff that keeps a person young.”