#beaver dams

[highways-are-liminal-spaces]

Phantom Lake, Wisconsin

Taken May 2024

[rjzimmerman]

Deep in the Wilderness, the World’s Largest Beaver Dam Endures

The largest beaver dam on Earth was discovered via satellite imagery in 2007, and since then only one person has trekked into the Canadian w

Good story from Yale Environment 360, without a paywall (I think), about beavers, public land, wildfires, endangered species, the largest beaver dam in the world, the degradation of that land and the large pond behind the dam due to the tar sands mining activity in the vicinity. In other words, a microcosm of all the bad stuff and good stuff intersecting in one place in Canada. Excerpt from this story:

Wood Buffalo National Park, the largest national park in Canada, covers an area the size of Switzerland and stretches from Northern Alberta into the Northwest Territories. Only one road enters it from Alberta, and one from the NWT. If not for people observing it from airplanes and helicopters, and satellites photographing it, little would be known about big parts of it. The park is a variety of landscapes — boreal swamps, fens, bogs, black spruce forests, salt flats, gypsum karst, permafrost islands, and prairies that extend the continent’s central plains to their northern limit. The wood buffalo in the park’s name are bison related to the Great Plains bison. In this remoteness, the buffalo descend from the original population, and the wolves that prey on them are also the wild originals. Millions of birds summer and breed here. The park holds one of the last remaining breeding grounds of the whooping crane.

Other superlatives and near-superlatives: the delta in the park’s southeast where the Peace River and the Athabasca River come together is one of the largest freshwater deltas in the world; last summer, some of Canada’s largest forest fires burned in the park and around it; and — just inside the park’s southern border — is the largest beaver dam in the world.

The dam is about a half-mile long and in the shape of an arc made of connected arcs, like a recurve bow. The media has known about it for 16 years, and in that time no bigger beaver dam has come to light, so it’s still known as the biggest, and scientists believe it almost certainly is. Animal technology created it, but human technology revealed it.

Many of the beavers that have reestablished themselves globally are descended from beavers that were planted by wildlife biologists. The thriving beaver population of Tierra del Fuego (another place Thie has studied) is descended from beavers brought to Argentina from Canada’s Saskatchewan River, who are themselves scions of beavers transplanted from upstate New York. No reintroduction of beavers was done in Wood Buffalo Park. Thie believes that the beavers who built the dam are of original stock. Like the wood buffalo and the wolves, they were too remote to be wiped out.

The park is suffering the worst drought in its history. Flows are down by half in many places, owing to climate change, water diversion, poor seasonal snowpack, and dams on the Peace River, upstream in British Columbia. A danger that seems inescapable comes from the oil sands that are being mined for crude-oil-containing bitumen, and from tailing ponds that hold trillions of liters of mine-contaminated water. The ponds are near the banks of the Athabasca River, just upstream from the park boundary. They are fatal to birds that land on them. Given the direction that water flows, conservationists and native people fear the tailings will pollute the park eventually. Toxic chemicals have already been found in McClelland Lake, just southeast of the park. Locals stopped taking their drinking water from the lake years ago.

Gillian Chow-Fraser, the boreal program manager for the Northern Alberta chapter of the Canadian Parks and Wilderness Society, in Edmonton, travels in the park often by helicopter, canoe, and foot. She has described the park’s environment as “super degraded.” When I spoke with her by phone not long ago, she talked about a recent tailing basin leak that was not reported to the First Nations downstream of it for nine months. In places that used to flood regularly but now don’t, the land is drying out and vegetation disappearing. Though she crisscrosses the park, she has never seen the world’s largest beaver dam, but she’s grateful that it’s there and bringing the park attention.

[climatecalling]

Beavers are heat wave heroes

Animals don’t have AC. But they have beavers.

During an intense heat wave, humans have a number of tools to stay cool, such as air conditioning, swimming pools, and ice cream. Wild animals, meanwhile, have beavers. Yes, beavers. These web-footed, fat-tailed amphibious rodents help countless other critters survive a heat wave. They not only drench certain landscapes in cold water but also help cool the air. They even make forests and grasslands less likely to burn. ... In one recent study, scientists relocated 69 beavers to a river basin in northwestern Washington state, and found that, on average, their dams cooled the streams by more than 4 degrees Fahrenheit (2.3 Celsius) during certain times of the year. Another study, published in 2017, saw similarly large drops in temperature after beavers built dams. ... As all that water in a beaver habitat starts to evaporate, the air cools down. That’s because turning water into vapor requires energy, and some of that energy comes from the heat in the air, Fairfax said. (This is how swamp coolers, or evaporative coolers, work; it’s also the same reason sweating cools the body down.) ... A study published in 2020 showed that areas full of beaver dams are “relatively unaffected by wildfire,” compared to similar but dam-less habitats. ... Instead of just relying on human-made technologies and infrastructure, we can also restore species like beavers to the landscape. “They’re out there and we can definitely take advantage of that,” Fairfax said. It just requires “working with nature,” she said, “instead of constantly against it.”

[flowersandspacestuff]

Beaver lessons in economics: spreading out the water makes ecosystems more resilient, and helps sustain thriving biodiversity. Spreading out the money makes communities more resilient, and helps sustain thriving economic diversity.

Dam the money flow. Create beaver ponds and beaver meadows of shared wealth to support healthy and drought tolerant economic systems.

[uwmspeccoll]

SPOTLIGHT: Beavers Building their Hutts!

The second edition of The World Displayed; or, A Curious Collection of Voyages and Travels, selected from the Writers of all Nations was published in 20 volumes and printed in London by John Newbery in 1760. We only hold volume 5, which includes a section on “The Discoveries of the English in America” (our catalog record, which identifies our copy as a fourth edition with different printers and a later set of dates, appears to be incorrect, as the title page of our copy clearly has the 1760 imprint with J. Newbery as printer). 

NOTE: The cataloging record has since been corrected.

The section on the English discoveries includes this curious copperplate engraving of a construction crew of beavers building their rather angular, fortress-like “Hutts.” Here the beavers are depicted as an orderly and well-organized work gang that stand upright and haul lumber onto their shoulders, carrying them in procession to construct a very geometric pattern that has the impression of being designed by a master engineer. If Americans are reluctant to take construction jobs in these post-Covid times, perhaps we can employ beavers!

John Newbery was a noted, early publisher of books for children, so at first we thought the illustration was designed to appeal to the imaginations of children, or perhaps it was just a joke. We checked the other engravings in the book, however, and neither seems to be the case as the other engravings are quite accurate and rather serious. The written description of beavers also seems fairly accurate (no mention of bipedal beavers slinging lumber onto their shoulders!).

Although the title page notes that the book is “Illustrated and Embellished with Variety of Maps and Prints by the best Hands,” it appears that this illustration is just the work of a poorly-informed engraver who has clearly never seen real beavers at work. It’s still a hoot to see, however!

[duck-duck-gay-duck]

Went out for a rip on the canoe

[rjzimmerman]

The Newest Threat to a Warming Alaskan Arctic: Beavers

The large rodents are creating lakes that accelerate the thawing of frozen soils and potentially increase greenhouse gas emissions, a study finds.

Excerpt from this story from InsideClimate News:

Alaskan beavers are carving out a growing web of channels, dams and ponds in the frozen Arctic tundra of northwestern Alaska, helping to turn it into a soggy sponge that intensifies global warming.

On the Baldwin Peninsula, near Kotzebue, for example, the big rodents have been so busy that they're hastening the regional thawing of the permafrost, raising new concerns about how fast those organic frozen soils will melt and release long-trapped greenhouse gases into the atmosphere, said scientists who are studying the beavers' activity.

The number of new beaver dams and lakes continues to grow exponentially, suggesting that "beavers are a greater influence than climate on surface water extent," said University of Alaska, Fairbanks scientist Ken Tape, a co-author of a new beaver and permafrost study published today in the journal Environmental Research Letters.

On the Baldwin Peninsula, Tape said the beavers are following a northward spreading belt of shrubs and trees, part of an intensifying cycle of Arctic changes driven by global warming. As they go, they destabilize permafrost and trigger a cascade of effects.

"They build a dam, the pond water gets deeper, it floods a bunch of tundra, which absorbs more heat than the permafrost," Tape said. "It thaws vertically down and to the sides and it collapses the banks."

[rjalker]

Did I post the beaver dam yet

Me: wow, the creek is really high! I wonder if there's a beaver dam?

*5 seconds later* oh, yep, there it is!

(it's hard to tell in the pic, but this dam has raised the creek level by like, 3 ft)

Public domain!

[ID: A photo of a brown creek with a beaver dam made of layered logs and stick crossing the middle, with some fallen leaves floating in the upper section. There is a forest on the other side of the creek, and yellow grass in the forgeound. End ID.]