(Illustration: Kevin Jeffers/The Colorado Sun; Canva)
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Like other old-timers in the Gunnison Valley, Sam Pierce’s ranching ancestors used to blast beavers and their dams and lodges with dynamite. They viewed beavers as nuisances — nothing more than big rats that flooded their fields and could scramble water rights with their diversions.
Now, Pierce, a Stanford University Ph.D. student, and a contractor with the U.S. Department of Energy and Rocky Mountain Biological Laboratory, is back in his ancestral valley researching the good that the cursed rats of old do around the beaver stronghold of Crested Butte.
His conclusion: Beavers are “nature’s engineers, hydrologists and biochemists.”
Sam Pierce measures the distance across a beaver dam on Trail Creek in the Gunnison National Forest. (Dean Krakel, Special to The Colorado Sun)
Pierce’s differing family views offer a good example of beavers being highly controversial critters.
An ecologist or an animal lover might describe them as darling little ecosystem engineers with nearsighted eyes, buck teeth and tubby rear ends. When they build their ingenious humps of wood and muck on waterways, they are praised for bringing lands alive with lush threaded wetlands that offer resiliency in droughts and wildfires.
On the other hand, a rancher or streamside homeowner might counter that they are just smelly rats — rats with a single-minded penchant for property damage. They gnaw down landscaping and cause floods with their incessant dam building.
Enter Colorado Parks and Wildlife, the agency still reeling through the controversy of trying to manage voter-mandated wolf reintroduction. This month, CPW is having to wade into the middle of the contentious beaver debate and come up with a management strategy for an animal considered a keystone species. That means an entire ecosystem would change drastically without the presence of beavers.
Any management strategy CPW comes up with will have to fall somewhere between controlling “rodenta non grata” and preserving the hottest little fur bearers since capybaras overwhelmed TikTok with cuteness.
LEFT: A beaver maintains her lodge on Trail Creek by packing it with mud. (Courtesy: Dave Sutherland, EcoMetrics) RIGHT: Paul Vertrees walks past the handiwork of beavers along Grape Creek in Fremont County in December of 2020. (Mike Sweeney, Special to The Colorado Sun)
Enthusiasm for our flat-tailed friends is, well, building
Beyond the serious environmental work of beavers, the creatures are totally having a moment. Their popularity infuses CPW’s mission with emotional import on top of scientific input.
There are scads of North American beaver advocacy and research organizations spread from Worth A Dam in Martinez, California, to the Beaver Institute — with its own Beaver Library — in Southampton, Massachusetts. Colorado is home to Give a Dam, the Kawuneeche Valley Restoration Collaborative, the Colorado Beaver Working Group, Pitkin County Healthy Rivers, and the Bird Conservancy of the Rockies. The latter is included in beaver groups because it views beavers as “our secret superheroes.”
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Beaver conventions and festivals have popped up like dams on a meandering mountain stream in recent years. So have beaver books, beaver classes, and, of course, beaver swag.
Last year, the Beaver Institute’s BeaverCon brought more than 500 beaver enthusiasts to Boulder from around the world for six days of all things beaver. In addition to serious discussions of the newest ideas in beaver ecology and management, attendees scooped up cartoon beaver caps and T-shirts and beaver-chewed sticks that had been turned into pencils.
Durango hosted a beaver festival in June that featured a beaver theater presentation and a beaver parade.
New cadres of beaver helpmates have also popped up along streams and ponds. There is a fairly new specialty of human dam builders who slop around in streams copying beavers’ stick-built schematics. The humans build beaver dams, which essentially serve as speed bumps on waterways and help create wetlands. The hope is that the mimicry will entice beavers to return to areas where they once lived.
There are also beaver conflict resolution specialists like Paul Planer of Gunnison. His mission is just what it sounds like: solving problems between castor canadensis and hominids — the two species credited with having the most impact on the Earth’s environment.
“It’s highly frustrating. Beavers have had a nuisance title hung around them for so long,” Planer said about his part-time beaver-trouble gig. “Beavers are an agent of change, and some people don’t like change.”
CPW is also tackling that stigma through its Beaver Conservation and Management Strategy scoping period. The agency has designated August as a time to sort out some of the arguments over beavers. That involves bringing together beaver experts, beaver haters, beaver hunters and beaver proponents to weigh in on the creatures’ future in Colorado.
“I’ve been pleasantly surprised. So far, there hasn’t been that much controversy,” said Boyd Wright, CPW’s native aquatic species coordinator. “People who have beaver concerns are getting their concerns heard.”
Wright said he is detecting more respect for beavers in the steady stream of public commenters and in focus group sessions that are tackling topics like beaver harvest regulations, translocation policies, and techniques for coexistence.
“Waddling pears” on land are balletic under water
That kind of bureaucratic policy structuring can almost make beavers sound boring. They are anything but.
True, they are rodents — the second-largest rodents in the world after the South American capybara. At up to 60 pounds, beavers can equal the heft of a Labrador retriever.
Beavers’ leathery, oil-filled tails are one of their most unique parts. They use them to slap water with a crack that can sound like a cherry bomb. It is designed to send a don’t-mess-with-me message to intruders and a warning to pond mates.
Beavers’ webbed feet serve two functions. The clawed forepaws are well-designed diggers. All four feet propel beavers through water in fluid, balletic displays that are prolonged by their ability to hold their breath underwater for up to 15 minutes.
Swimming is key to beavers’ survival because they are not at all graceful or quick on land. Ben Goldfarb, in his seminal book on beavers titled “Eager,” accurately calls beavers “waddling pears” on land.
That clumsiness is behind their drive to continually work at raising water levels on streams and ponds. They need that water to survive. When they are on land, they are exposed to predators.
Beavers are an agent of change, and some people don’t like change.
— Paul Planer, Beaver conflict resolution specialist
Beavers have a few other odd attributes that suit them to life lived in water. They have transparent eyelids so they can see underwater and two sets of lips so they can chew and drag wood and vegetation through water without drowning. The second set of lips is hidden behind their big orange teeth.
Those teeth aren’t the color of clown shoes because they are dirty. They are loaded with iron, which makes them strong enough to chomp down mature trees. A beaver can topple a 5-inch diameter tree in half an hour.
Beavers only eat vegetation — greens in summer and more bark in winter. Contrary to a general misconception, they don’t eat whole trees. They topple them to get at the leaves and bark. They stash that food in their lodges. They also stuff caches of greenery, bark and sticks under rafts they build and float near their lodges.
Fur fashion nearly drove beavers to extinction and they’re still hunted
Beavers’ unique fur got them into trouble and nearly drove them to extinction when explorers and trappers touched off a craze for beaver hats to keep the heads of dandies, monarchs, presidents and soldiers toasty. Beaver fur has two dense, oily layers making it exceptionally warm and water-repellent.
Before European explorers arrived, the castoroides, some the size of small bears, had been at their busy work for 7.5 million years. There were once as many as 250 million beaver ponds across North America, according to Goldfarb.
There are no good numbers for just how many beavers are chewing their way across the country now. Wright estimates there could be 60,000 to 90,000 in the southern Rockies. A Colorado Beaver Activity map shows beaver areas marked by yellow dots. On the Continental Divide and to the west, the map looks like it has been scattered with heavy pollen, evidence that beavers prefer high mountain headwaters areas.
Beavers are no longer widely trapped for their fur. It is not worth much in an era of ripstop hoodies.
But there are still beaver hunters out there.
Last year, CPW counted about 1,000 beavers “harvested.” Wright said questions to hunters about where the beavers were killed indicate it wasn’t just for sport. Landowners likely hired some of those hunters to rid their properties of the dam builders as 536 of which were taken on private land. There are no bag limits for hunting beaver in Colorado.
Through its management strategy phase, CPW is hoping to lessen the need for that beaver blasting. The keyword in CPW’s beaver strategizing is “coexistence.”
That includes improving tolerance for beavers’ presence by using flow devices on beaver ponds to control water levels and lessen floods; putting rigid fencing or sanded paint around trees; and using cages to keep beavers from plugging up culverts and overflowing roads. Those devices are all lumped under the category of “beaver deceivers.”
Paul Planer walks in front of a Keystone Fence that he put in place to prevent beavers from plugging a culvert along Cement Creek road near South Crested Butte. (Dean Krakel, Special to The Colorado Sun)
When coexistence isn’t possible, “translocations” are another step. Translocating beavers means trapping them and moving them to a new home. The success rate is not high because beavers tend to return to their previous neighborhoods, especially if some of their offspring, known as kits, have been left behind. Translocations also come with the danger of introducing pathogens to new waterways.
Beaver numbers are somewhat hard to push up because beavers are unlike most other rodents when it comes to reproduction.
Beavers mate for life and have one to six kits per year. Those juveniles tend to hang out with their parents in the home lodges for up to two years before they swim off to stake out and dam their own ponds. Some lodges hold three generations of beavers.
Humans build dams to mimic the real thing
Mark Beardsley, who owns the Buena Vista-based EcoMetrics restoration company, has spent the past eight years trying to spread more beavers around mountain waterways. He builds beaver dams with the aid of Google Earth and digging machines. He calls these human-built dams “analogues,” or “mimicry dams” because, compared to real beaver-built dams, his structures are more like an Ikea furniture project than something built by an expert woodworker.
“We try to build like the beavers would, but their dams are bigger and better, and they are maintained 24 hours a day,” Beardsley pointed out.
Mark Beardsley poses in front of a beaver dam on Trail Creek. The dam and waterways were restored by the Beaver Institute’s Beaver Corps and Beardsley’s company EcoMetrics. (Dean Krakel, Special to The Colorado Sun)
Beaver-built dams are so strong that a full-sized moose can stroll across them without punching through. They are strong enough to create a problem for paddleboarders on the Slate River near Crested Butte. Much to the dismay of Beardsley and other ecologists, boarders have several times hacked and ripped a gap in a long-standing beaver dam so they can paddle through.
The damage doesn’t last long. The beavers — in true beaver fashion — just set to work repairing the damage.
Beardsley’s goal with the human-built beaver dams is to lure beavers back to waterways where they lived historically. Currently, he is working in the South Park area where he said his goal is to help nature, not reengineer it.
Pierce is part of a similar project high on the Taylor River above Almont — not all that far from where his ancestors blasted beavers with dynamite.
Dr. David Rey of the Hydrologic Remote Sensing branch of the the United States Geological Survey looks for places to put sensors that will take seismic measurements of the ground beneath a restored beaver dam on Trail Creek in the Gunnison National Forest on Aug. 7. (Dean Krakel, Special to The Colorado Sun)
His sampling around beaver ponds — both human and beaver built — is focused on showing how much beavers affect water quality, not just quantity. Beavers can alter the hydrology and affect the level of nutrients and minerals in the water.
Pierce calls everything beavers do for the environment “chaos.”
“It’s good chaos they can bring,” he said.
And he believes more longtime residents who used to wage war on beavers are coming around to embracing that beaver chaos. Even some of his relatives may have changed their point of view.
“It definitely seems like folks are catching on,” he said. “They are realizing that beavers are so impactful at modifying landscapes. And they do it for free, and they are so good at it.”
Type of Story: Explainer
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