They Will Build It
It’s before dawn on a late August morning, the Washington sky blanched with smoke drifting from distant wildfires, and Molly Alves and David Bailey have caught a beaver.
The two biologists haul the ornery package of fat and fur, still penned into the trap that closed around him overnight like a giant clam, up the banks of a meandering, tea-colored stream. The drainage is cluttered with Himalayan blackberry and Japanese knotweed, whose rhubarb-like stems the beaver has commandeered to build his lodge—a native mammal thriving amidst invasive plants. The beaver, his lustrous fur shimmering in the pale light, flaps his tail and gnaws at the trap with burnt-orange incisors. His forepaws grasp the wire mesh, a prisoner straining against his cell walls.
“That is a very feisty sub-adult,” Bailey grunts as he and Alves lug the beaver toward the road. “When they’re trying to nom on the trap like that, it means they’re pretty stressed.”
Although not Indigenous themselves, Alves and Bailey relocate beavers under the auspices of the Tulalip Tribes, a sovereign nation with nearly 5,000 members. This week they’ve set their traps in the Puget Sound suburb of Marysville—half an hour north of Seattle if you leave before daybreak, an eternity at rush hour. Across the street from the Marysville Public Library waits their Silverado pickup, its right two wheels perched on the curb. Alves and Bailey, foreheads damp with sweat, set the beaver down and lower the tailgate. Morning traffic roars past, drivers craning their necks.
An elderly pedestrian wanders toward us, snatching up candy wrappers and soda cans with a long-handled trash picker. Ah, I think, a good Samaritan, out for a spot of neighborhood cleanup. If anyone would appreciate local fauna, it’s this guy. I sidle up and point out the beaver, now being boosted into the truck.
The man gazes at me, his eyes a milky blue. “What are you going to do with him?”
Relocate him, I reply.
The man smiles. “Why don’t you just shoot the son of a bitch?”
I am momentarily flabbergasted. I sputter something about transferring the beavers to nearby public lands where they can build dams, create wetlands, and do some ecological good. He cuts me off.
“Good?” he laughs. “What good do they do? They’re always clogging up culverts and being a pain in the ass. You’re lucky you got to him before I did.” Before I can craft a response, he snaps up a crushed water bottle and strolls off.
The sentiment that Castor canadensis is little more than a tree-felling, water-stealing, property-flooding pest is a common one. In 2017, trappers in Washington State killed 1,700 “nuisance” beavers, nearly 20 times more than were relocated alive. In neighboring Oregon, the herbivorous rodents are classified as predators, logic and biology notwithstanding. California considers them a “detrimental species.” Last year alone, the U.S. Department of Agriculture eliminated more than 23,000 conflict-causing beavers nationwide.
Running countercurrent to this carnage is another trend: the rise of the Beaver Believer. Across North America, many scientists and land managers are discovering that, far from being forces of destruction, beavers can serve as agents of water conservation, habitat creation, and stream restoration. In Maryland, ecologists are promoting beaver-built wetlands to filter out agricultural pollutants and improve water quality in Chesapeake Bay. In North Carolina, biologists are building beaver-like dams to enhance wet meadows for endangered butterflies. In England, conservationists have reintroduced the Eurasian beaver (Castor fiber) in hopes that their pond complexes will attenuate destructive floods. And in Washington, where a century of habitat loss has devastated salmon, the Tulalip Tribes are strategically dispatching beavers to support the fish so integral to their history and culture.
Back at the truck, I recount my exchange with the beaver-abhorring walker. Alves laughs. She has heard such slander before, and has a rebuttal at the ready.
“I would have asked him if he likes fresh water and salmon.”
Yet the victory was, in some ways, a hollow one. The Puget Sound’s salmon were in freefall, the victims of dams, overfishing, and the Seattle area’s explosive growth. Thousands of acres of marsh had been paved over, hundreds of embayments wiped out. Beaches had been bulwarked, lowland forests demolished. What use was having your right to fish confirmed by the courts if there were no fish to catch? “We’d lost so much natural water storage,” says Terry Williams, the Tulalip’s treaty rights commissioner. “We needed to come up with plans for longer-term watershed recovery, to have natural approaches that allow ecosystems to restore themselves.”
Williams, a genial and gravel-voiced tribal member, grew up on the Tulalip Reservation in the 1960s, eating not salmon but government rations—hardtack, crackers, butter dyed with yellow food coloring. “We’d have to filter all the flour and take the bugs out before we could use it,” he recalls. Williams spent his youth tromping through the reservation’s woods and tracking its fauna, including beavers. He and a young cousin caught juvenile beavers alive, wrangled them into sacks, and relocated them to wetlands near their home to watch them work—for no other reason, he says, than that he was “13 years old and curious.” They caught raccoons, too, which they kept in the house. “My mom’s sister went a little crazy when they started going through the cupboards.”
After a stint in Vietnam, Williams returned to Washington to work for a railroad company and attend college via the GI Bill. He tried commercial fishing in Puget Sound for a season, netting salmon to sell and flounder to take home. In the early 1980s some friends asked if he’d consider working for his Tribe’s fisheries department—just for a year, they promised. The Tulalip Tribes were then embroiled in legal struggles all over Washington State in defense of their members’ fishing rights, and Williams spent seven days a week on the road, preparing arguments and sitting in on court sessions. A year on staff turned into two, ten, a career. In the decades since, Williams has directed the Environmental Protection Agency’s American Indian Environmental Office, served on the United Nations’ Convention on Biological Diversity, and held a seat on just about every board, council, and commission pertaining to salmon recovery in Puget Sound. “I just got addicted to it,” he laughs.
Around 2007, Williams began to ponder beavers. One of his friends, a farmer in Whatcom County, had harvested a bumper crop after beavers built ponds on his property and lengthened his irrigation season. Williams recalled his own childhood experiments in beaver relocation, and began to wonder if rodent restoration might be the “natural approach” the region’s salmon habitat so badly needed. “He brought up beaver in just about every meeting for years, to the point that he drove people crazy,” recalls Abby Hook, a former hydrologist with the Tulalip’s treaty rights division. “They’d say, okay, let’s talk about (Clean Water Act) permits. And he’d say, no, let’s talk about beaver.”
In 2013, Williams found a sympathetic soul in the person of Ben Dittbrenner, the founder of Beavers Northwest, a group dedicated to helping landowners coexist with the meddlesome mammals. Dittbrenner hoped to study the benefits of beaver relocation for his PhD at the University of Washington; now all he needed were some beavers to relocate. The Tribe had the desire and the resources, Dittbrenner the beaver expertise. He and Jason Schilling, a tribal biologist, developed a computer model to identify gentle, low-gradient streams ideal for beaver releases, then spent months traipsing the Skykomish River Basin, ground-truthing prospective relocation sites.
Before the project launched, though, it had to overcome a legal obstacle. The previous year, the state of Washington had passed a bipartisan “Beaver Bill” praising beavers’ ecological value and encouraging their relocation. Although the legislation was well-intentioned, it contained a grave flaw, a provision inserted by a beaver-fearing legislator on the Olympic Peninsula. While the law permitted biologists to move beavers around sparsely settled eastern Washington, it prohibited releasing them west of the Cascades—the region that’s home to Seattle, Tacoma, Olympia, and most of the state’s other population centers. The message: Beavers can do good, but keep the damn things away from people.
Still, the Tulalip’s lawyers were undaunted. The Tribe’s authority to manage wildlife superseded the state’s, they argued, and their treaty rights gave them the ability to restore salmon habitat as they saw fit. The Tribe struck a deal with the U.S. Forest Service, which was hungry for more beavers on public land. In 2014, its inaugural year, the Tulalip Beaver Project relocated 23 beavers onto federal acres in the Skykomish River basin. “They’re doing us a service all the way around,” says Joe Neal, a district ranger on the Mount Baker-Snoqualmie National Forest. “Anything we can do to hold water up here, that’s good.”
Through 2018, the project—which brought aboard Molly Alves in 2014 and David Bailey the next year—has moved 122 beavers to 20 locations around the Skykomish. Seven of those sites were first populated this year, meaning it’s still too early to know whether the relocations have taken. At the 13 sites whose success the Tulalip can assess, beavers have established six colonies and constructed more than 12 acres of wetlands—more than 10 football fields’ worth of the West’s most important ecosystem.
Merely quantifying the impact of released beavers, however, misses the project’s point. When the Tulalip Tribes began releasing rodents, Dittbrenner’s modeling suggested that around three-quarters of the suitable beaver habitat in the Skykomish was vacant—a gap too large for any relocation effort to fill. Instead, the Tulalip’s hope is to jumpstart a natural re-beavering of Puget Sound’s uplands.
“The whole idea is to seed the watershed in high-quality areas where colonies will persist and crank out lots of baby beavers, sending out offspring and repopulating the watershed,” Dittbrenner explains. “That’s the really important assumption about what’s going to happen.”
The beaver now safely ensconced in the pickup, Alves and Bailey drive back to the nearby Tulalip Reservation to examine their buck-toothed prize. The heart of the Tulalip Beaver Project is the Tribe’s fish hatchery, a compound of pools and pens that pumps out 11 million chinook, coho, and chum salmon fry each year. When they’re not holding salmon, the gnaw-proof concrete walls and flowing water within the hatchery’s raceways also make them perfect beaver enclosures.
At the hatchery, Alves and Bailey swiftly process their ward. They place the trap on a scale, which registers the creature’s weight at around 30 pounds—a juvenile, Bailey says—snip a hair sample, and staple color-coded tags in the animal’s ears for future identification: white in the left, yellow in the right. Although the biologists handle him as tenderly as possible, the beaver doesn’t enjoy the poking and prodding, and begins to chatter his teeth as though cold—another sign of stress.
Once he’s had a few minutes to calm down, Alves and Bailey usher the beaver into a cloth sack, with only his withers exposed, for the most sensitive step: sexing. Because even males possess internal genitalia, conclusively determining a beaver’s sex can’t be done visually; instead, it requires some serious olfactory skills. Alves presses on the beaver’s belly, feeling for his anal glands—nubbins of flesh whose secretions beavers use to mark their territories and tell friend from foe. The anxious beaver has clenched his tail, making matters more difficult, but at last the glands emerge, like pinkish teats, from the plush underfur. Alves squeezes gently, milking a dollop of viscous, yellowish fluid onto her gloved finger.
Males, they say, are redolent of motor oil. Females smell like old cheese.
Alves wrinkles her nose. “Male,” she confirms.
“It’s kind of musky and urine-y,” Bailey opines later. “At this point it’s all over my waders, and it’s never coming out. Sometimes I’ll be in the car and suddenly smell it and think, oh, where’s the beaver?”
His ordeal mercifully concluded, the beaver is released into one of the raceways, gliding up the narrow pen to huddle against the far wall. A cinderblock hut, floored with woodchips, stands at the raceway’s center. When we return the next morning, we’ll find that he’s settled into the makeshift lodge to await a family reunion. Beavers are kin-oriented creatures, with as many as 10 family members sharing a lodge: the mating adults, their newborn kits, one-year-olds, and two-year-olds. (The latter depart the colony each spring in search of their own territories, like college-bound teenagers.) Relocate a beaver by himself and he’s liable to wander the landscape, searching for companionship, until he’s devoured by a bear or cougar. Move him with his clan, and he’s more likely to stay put and build.
The Tulalip beaver relocation effort, like most projects of its kind, thus strives to capture and release cohesive families. When they catch unattached beavers, they attempt to match them at the hatchery, like a rodent dating service. “If you give them a few nights together, they usually pair up,” Alves says. “They get lonely—they want to be with other beavers.”
When all goes well, relocation can produce spectacular results. Later that week, Bailey and Alves drive me to a stream high in the Mount-Baker Snoqualmie National Forest, the 1.7 million-acre block of Douglas fir and western red cedar that sprawls across the western flank of the Cascade Range. The Tulalip had dropped a family of seven beavers in this creek in the fall of 2015. Nothing happened at first, and Alves and Bailey concluded the site was a bust. When they found signs of dam-building the next spring, they figured another colony had moved in on its own. Grainy camera trap footage, however, revealed that the nocturnal construction workers bore the Tulalip Tribe’s ear tags. The relocation had worked after all.
Now, a lonely beaver outpost has blossomed into an empire. Eleven separate dams have transformed the stream from a string-straight, free-flowing riffle into a patchwork of sun-dappled pools and serpentine side channels. We teeter along felled trunks and bushwhack through thickets of vine maple, exploring a complex that seems only to expand as we press on. The vast maze of channels and ponds would be an impressive feat for an engineer in a backhoe; for a handful of rodents armed only with incisors, it’s practically miraculous.
The largest dams are graceful crescents of latticed wood, buttressing serene ponds with yellow alder leaves swirling across their surface—the platonic ideal of beaver infrastructure. Others are loose stickjams that hold back only a turbid bathtub. “I think they were drunk when they made this one,” suggests Bailey, eyeing a crooked, homely ridge of mud.
For the salmon thriving in this beaver-built paradise, even the humblest dams provide key habitat. Everywhere we look, we see shoals of coho fry milling about the pools, their orange-edged fins waving like pennants as they flee our shadows. Behind one dam glitters freshly swept gravel marking a pair of redds, or salmon nests—a visible rebuke to those who still claim that beaver dams block fish passage. We’re high in the western Cascades, hours by car from the Puget Sound lowlands, yet beavers and salmon have connected this slender stream to the sea.
While expanded ponds are beavers’ most visible hydrologic impact, their ability to recharge groundwater might be an even greater contribution. At the Tulalip’s relocation sites, Ben Dittbrenner has found that for every cubic meter (264 gallons) of surface water beavers impound, another 2.5 cubic meters (660 gallons) sinks into the earth. As that water trickles through the soil, it cools off, eventually reemerging to mingle with streamflows downriver. Elsewhere, such hyporheic exchange between surface- and groundwater keeps streams hydrated later into the dry season, turning seasonal creeks perennial. Dittbrenner’s research suggests that beaver-facilitated cooling and mixing also reduces water temperatures by more than 2 degrees Celsius (about 3.5 degrees Fahrenheit), a huge boon for heat-sensitive salmon and trout.
Although beavers won’t singlehandedly save us from climate change, such findings suggest they might be able to help our stressed water supplies adapt to a warmer future. “By 2100, we’re expecting to see snowpack, which is basically our water storage reservoir, disappear throughout a lot of the Cascades,” Dittbrenner says. “I’m curious whether beavers could make up an appreciable storage component of that lost snowpack.”
Yet beavers’ drought-fighting powers only go so far. After our visit to the salmon mecca, Alves and Bailey take me to another stream complex, dubbed Mahoney, where the Tulalip introduced beavers in 2015. The creatures had done their job with aplomb, reconnecting several disjointed, fishless channels into a massive pond buttressed by a sturdy 100-foot dam. I’d visited Mahoney the previous summer and found its waters vibrating with coho fry—a shining example of all that beaver relocation can achieve. “You know it’s succeeded when you need a flotation device to monitor your site,” Bailey had joked then.
When we emerge into the Mahoney clearing this year, though, it’s apparent that no watercraft will be necessary. Catastrophe has plainly befallen the colony. The vast pond has receded into a handful of scattered puddles, exposing the beavers’ once-impregnable lodge—now a sad, vulnerable pile of brittle sticks. Thickets of ghostly dead alder stand marooned atop muddy hummocks. Deer and bear tracks pock the soggy ground, suggesting that new visitors are already taking advantage of sprouting sedges and grasses. The scene has the mysterious, dilapidated grandeur of a medieval ruin.
“This is still a functioning space, and it’s obviously beautiful in a different way,” Alves says as we survey the abandoned kingdom. “It’s aeons better than it was when we found it.” Still, there’s no mistaking the disappointment in her voice.
Beavers abandon sites for all kinds of reasons, from disease to predation to food depletion. At Mahoney, though, Alves and Bailey suspect a different culprit: drought. The previous summer, the stream that fed Mahoney had completely dried up, cutting off the site’s spigot. Beavers are geniuses at capturing running water, but they cannot conjure it from thin air.
Even in the best of times, getting beavers to stay where you put ‘em poses immense challenges. When biologists dumped more than 200 beavers into Wyoming streams in the 1990s, for instance, many fell prey to bears, cougars, and other carnivores. Altogether, fewer than 20 percent took to their new environs. As drought diminishes western Washington’s beaver carrying capacity, persuading the rodents to stick around has become harder still.
“With these sites drying up earlier in the year, we’re running out of places to put these beavers,” Alves says. “We didn’t anticipate that four years ago.”
So how do you get beavers to cooperate? One option: Give them a leg up. After touring Mahoney, we jounce up yet another endless string of dirt roads to yet another remote tributary, this one shielded from the road by a verdant screen of maple and Devil’s club. The Tulalip had installed beavers here a year ago, with disheartening results. “They just kind of waddled off, never to be seen again,” Bailey says.
To entice the next colony to stay, Bailey and Alves have decided to attempt a new tactic—human-built walls of wooden posts and sticks known as “beaver dam analogues.” The idea behind beaver dam analogues, or BDAs, is simple: In situations where suboptimal habitat discourages beavers from settling down, a human-assisted starter kit can persuade them to stay put and build dams of their own. In one Oregon stream where scientists built more than 120 beaver dam analogues, beaver activity increased eightfold—and juvenile steelhead trout survival spiked by more than 50 percent. Little wonder that BDAs are now among the American West’s hottest stream restoration techniques, deployed to enhance wet meadows for greater sage-grouse in Wyoming, remediate mining waste in Montana, and improve fish habitat in Northern California.
The appeal of beaver dam analogues is not merely that they’re effective—it is also that they are easy to install. Armed with sledgehammers, the Tulalip biologists and a few volunteers begin to thwack upright silver fir logs into the gravel streambed, pounding them a few inches deeper with each satisfying swing. The hollow thump of hammer meeting wood resounds in the summer air. Between the thuds the crew shouts encouragement.
“You’re a monster, David!”
“You’re a beast, Bethany!”
“Shiloh, you been working out?”
Soon the creek is picketed with two rows of vertical posts, slightly askew like a mouthful of crooked teeth. Coho fry flit around our boots, picking at insect larvae stirred up by the activity. Mike Sevigny, the Tulalip’s wildlife program manager, plops down on the bank, his shirt darkened by sweat, and pulls off the surgical mask he wears to filter the wildfire haze. While Sevigny spends much of his time managing elk—another creature of vital cultural importance to the Tribe—he considers beavers to be the center of terrestrial ecosystems as well as aquatic ones.
“Beaver ponds increase forbs, grasses, and shrubs, which are forage for bear, elk, deer, and everything else,” Sevigny says. “The beaver gave us so much we don’t understand because they’re gone. We don’t know how good the land could be because we never saw it. A lot of these habitats are screaming for help.”
We return the next day to complete the job. Shayna Schultz and Bethany Tegt, the project’s technicians, thread willow and maple sticks between the posts like basket weavers, then pack the interstices with straw to form a semi-permeable seal. Soon knee-deep water has backed up behind the ramshackle dams. The crude structures don’t look durable—they’ll likely blow out in a flood a few springs hence—but permanence isn’t the point. “They just need to last long enough to get beaver back into the system,” Alves explains as we slosh through the nascent pool. By furnishing a safe, attractive pond and a semi-stable base of operations, these beaver dam analogues will, with luck, convince the next relocated colony to stick around, get to work, and reproduce.
Thanks in large measure to the Tulalip’s example, tribal-led beaver restoration in Washington will soon take another leap forward. Among the volunteers at the beaver dam analogue installation is Erik White, wildlife manager with the Cowlitz Tribe. The Cowlitz’s southwest Washington territory encompasses the Lewis River, which in turn is home to bull trout, a cold-loving fish imperiled by climate change.
“A lot of projections show that 80 percent of bull trout habitat in the Lewis River basin is going to disappear in the next 25 years because of increasing water temperatures,” White says during a break in our post-pounding. Inspired by the Tulalip, he and the Cowlitz Tribe have launched a beaver relocation project of their own, and plan to begin moving the animals to the Gifford Pinchot National Forest in the spring of 2019. “We’ve got less and less snowpack every year,” White adds. “Beavers could be a way to spread flows out into a more natural hydrograph.”
Not only have the Tulalip spurred other tribes into action, they have also expended considerable political capital refining the Beaver Bill, the law that prevented relocations in western Washington. Although the Tribe’s unique legal status meant that it was never bound by the prohibition, the law’s illogic irked Terry Williams. More beavers on more Washington rivers would mean more salmon in Puget Sound, he figured. So, in 2017, the Tribe flexed its political muscle, dispatching a lobbyist to Olympia, the state’s capital, to advocate for a revision. The stubborn lawmaker who had opposed moving beavers west of the Cascades had retired, and a new Beaver Bill, this one permitting relocations on both sides of the mountains, sailed through. Starting in 2019, non-tribal groups, like environmental nonprofits, will be able to relocate the animals west of the Cascades, too. The doors to the re-beavering have been flung open.
Williams was pleased by the outcome, but not surprised. When he began his career in fisheries management decades ago, he recalls, he’d found that the Tulalip were subject to a skein of laws intended to thwart tribal fishing. He’d griped to the Tribe’s chairman about the legal obstacles. “Well, that’s not so difficult,” the chairman retorted. “If the law doesn’t work for you, change it.”
Williams chuckles hoarsely as he recounts the story. “Because of that simple statement,” he says, “I’ve changed so many laws I can’t count ’em anymore.”
In early October, I rendezvous once more with the Tulalip crew, this time on a winding forest road that parallels the Snoqualmie River. The summer’s wildfires have been quelled, and the morning is crisp and blue, lit by the sun cresting over the granitic spires of the western Cascades. I arrive in time to catch Schultz and Tegt unloading four wire cages, which between them hold seven hulking beavers. Fourteen beady eyes rove over their captors. The creatures—two adults, four one- or two-year-olds, and a skittish kit—were trapped out of a golf course near Tulalip, where they’d been irking the groundskeepers. “They all get along pretty well, so we think they’re from the same colony,” Schultz says.
We lug the crates down to a marshy tributary. A fork in the stream has created a natural impoundment, offering a prime release site and obviating the need for any beaver dam analogues. At the base of an alder copse, the crew has built a slapdash lodge, temporary barracks that will keep the beavers safe from bears and cougars until they can build a permanent home. The crew lifts each cage to the lodge entrance, opens the door, and watches the beavers trundle into the dark interior. Although a previous relocation here failed, Alves and Bailey hope the threat of oncoming winter will motivate this batch to immediately start building. “We usually have more late-season establishment success,” Alves explains in a whisper. “They’re in hunker-down mode.”
Collaborating with beavers, many scientists point out, confers extraordinary benefits: Rodent restoration is a natural, cost-effective strategy capable of tackling problems as diverse as nitrogen pollution and stream erosion. But beaver work can be as frustrating as it is rewarding. No matter how thoughtfully you choose release locations, no matter how many beaver dam analogues you install, beavers are wont to do what beavers are wont to do. For all the science that guides it, beaver relocation entails, on some level, an act of faith. Dig a wetland with a backhoe, and you can be reasonably certain it will still exist in five years. Outsource the job to beavers, and they might succeed beyond your wildest expectations—or, as at Mahoney, permit your pond to lapse into a meadow.
It is thus with considerable trepidation that we wait before the makeshift lodge to see how its new inhabitants react. For a time, all is quiet; then a chorus of grunts and gurgles, eerily akin to the cries of a human infant, rises from the hut. We hear the staccato rasp of incisors on wood. Through gaps in the slats we catch a flash of fur, a glittering eye.
Abruptly a snout, culminating in a quivering nose, pokes from the logs, followed by a plump torso and a leathery tail. It’s one of the adults, a male whose mahogany fur seems more suited to an orangutan. He slips into the still water and cruises up the creek, head high, alert to our presence but unafraid. We hold our breath as he reaches the cul-de-sac at the far end of the impoundment, performs a tight pirouette, and glides back toward his new home. His inspection complete, he squirms back into the lodge and vanishes from view—master, now, of his own fate.
Portions of this story appeared in the book Eager: The Surprising, Secret Life of Beavers and Why They Matter (Chelsea Green Publishing, 2018).
Love what we do? You can help.
We’re a free multimedia magazine without a paywall or intrusive ads—and we’d like to keep it that way. We believe these stories need to be told; that inspiring both a deep appreciation for life on Earth and hope for its future is a critical step toward a thriving planet. If you agree, please consider making a donation to help secure the future of bioGraphic. Every little bit helps.
Morgan Heim has been sneezed on by a whale, stampeded by bison, and nearly mistaken for salmon by hungry grizzly bears, all of which she took as great compliments—especially since they let her live to spy on wildlife for another day. Her work has appeared in such outlets as Smithsonian, BBC Wildlife, National Geographic NewsWatch, NPR, and High Country News, among others. You can find more of her work at www.morganheim.com.