From Beaver Believers to Beaver Deceivers: An Introduction to What Could Be Our Best Weapon Against Climate Change
Contributing Author: Christina Allen
Is it just me or does it seem like suddenly everyone’s talking about beavers? Ever since I read Ben Goldfarb’s book, Eager: The Surprising, Secret Life Of Beavers And Why They Matter 2019, I see beavers everywhere, in books, movies, research articles, news, even in songs (Dams are for beavers). I was so inspired when I found out all the things beavers do for the land, I became a little obsessed. I joined the Colorado Canyons Association and Colorado Open Space Alliance and the Colorado beaver working group, all in hopes of finding out more about beavers and beaver relocation in Colorado. I interviewed Sarah Koenigsberg, Director of the 2018 documentary “The Beaver Believers,” and learned about the passionate group of people, from scientists to writers to singers to hairdressers, who are fighting for the return of beavers to American rivers. I interviewed Aaron Hall, Senior Aquatic Biologist at Defenders for Wildlife, and found out why Beavers are so important.
Beaver close-up (credit Chris Canipe)
I have a lot still to learn, but I’m already a beaver believer. The first thing I learned, is that if you want to sound like you know what you’re talking about, don’t call them beavers. People in the know just say “beaver,” like, “Before beaver were all but wiped out by fur trappers, there were 4 or 5 beaver per kilometer of every single river and tributary in the entire United States.” You get used to it. I know this is a blog about farming, but now that I’m obsessed with beaver, I can’t talk about farmers, farms and food without talking about beaver. Drought, wildfire and water pollution - these all obviously have something to do with our ability to grow food, right? Well as it turns out, beaver are intricately linked to each of these processes. Beaver are like climate superheroes to me now. Shy, waddling, pear-shaped little superheroes.
Okay, so here’s the meat. Why beaver are important, where they went, and how they are making a comeback. I’ll make it as short as I can, and if you want to know more, check out the links below.
Beaver Basics
In my previous life as a science teacher, I taught about beaver adaptations by dressing kids up as beavers. They’d put on big teeth of course, and kids would get a chance to try to beat beaver’s ability to chew through a 5 1/2 inch diameter trunk in a few minutes. Many elementary students were surprised to learn they weigh less than the average beaver (between 40-70 and up to 100 pounds!) and that the beaver is the second largest rodent in the world (next to the capybara of South America). Beaver live on average 10-12 years (up to 20), mate for life, and live with their parents for two years. Kids would put on goggles to represent beaver’s translucent third eyelids (nictitating membranes). On beavers, everything is watertight, including ears and nose and their lips are behind their big teeth so they don’t ingest lots of water and wood chips while cutting and dragging wood through the water. Their teeth are self-sharpening chisels with hard enamel on the outside and soft enamel underneath. Their teeth never stop growing, so they need to chew constantly to keep their teeth from curving into their mouth and eventually killing them.
Beavers eat plants. Bark and cambium, roots and buds. They eat so much cellulose that they often eat it twice to get more nutrients out of woody material. Yes, I just said beavers eat their own poop. Beavers also build! The biggest known beaver dam was recently discovered in remote Alberta Canada. At 2,550 feet long, it can be seen from space and is the work of many decades and generations of beaver. Working and building nonstop is literally synonymous with the word beaver, as in “beavering away at the problem”. Besides needing to chew constantly, beavers are born with the instinct to build, which is triggered by the sound of running water. Beavers put in a dry cement block room will sit around doing nothing, but if a sound of running water is piped in, they will become activated and if given any kind of materials, they will build a dam 24/7 as long as the sound continues. Note that it is the sound, not the sight of running water, that triggers beavers’ building instinct. People began trapping beaver on a huge scale in North America in the 1600’s, starting in Canada, in response to a fashion craze for beaver hats. I always thought the hats were warm, because beaver fur is one of the densest, warmest furs, but what makes this 250 year-long beaver killing spree even worse is that the hats were just for fashion, and they didn’t even use the skin, but shaved the hairs off the pelt and felted them into dorky top hats that had no purpose. In the mid 1800’s, the fashion changed to silk hats and just like that, people stopped killing beaver. Before European contact, before beaver hats were in fashion, there were an estimated 400 million beaver in North America. They were trapped almost to extinction. Since the mid-1800’s, they have been slowly coming back, but today, almost 200 years later, there are still only an estimated 10-15 million beaver in North America, a mere 2.5% of their original population.
Beaver and Water
Beaver dams slow down water so that it can sink into the ground and spread out, creating ponds and wetlands, where it is stored and used during times of drought, like underground irrigation, an insurance policy against both flood and drought. Before beaver were nearly eradicated, North American rivers meandered more and were less straight. An average beaver dam complex is estimated to store 10 acre-feet, or three million gallons of water. Beaver ponds also filter out solids from water and create an environment where microorganisms can break down sediment and pollution before the water continues down stream. Things like fertilizer and feces release nitrogen and phosphorous and can cause algal blooms if they accumulate.
Left: pic of habitat in the prairie before beaver release (credit Aaron Hall) | Right: pic of beaver dam after release (credit Kelsey Martin)
Beaver and Wildfire
In the US West, wildfire is an increasing concern, with the 10 biggest fires on record happening since 2004 and coinciding with the driest years in history (EPA, April 2021). Research by Emily Fairfax, ecohydrologist and Assistant Professor at California State University Channel Islands, shows that streams without beavers burn three times more intensely than streams with beavers. She made a stop-motion animation to show how this works. She points out that even with billions of dollars, climate change is a very hard problem to tackle. Beavers do so easily what we have to work so hard to accomplish. Says Fairfax, “You won’t find restoration practitioners who will work 24/7, 365 days a year for free… Beaver complexes can keep an area green and growing, like an underground irrigation system, even in a prolonged drought… Beavers will help us, but we need to set the stage through restoration actions for them to do their work.”
Beaver lodge/pond (credit Aaron Hall)
Beaver and Climate Change
Beaver dam complexes store millions of gallons of water, which promotes plant growth, which sequesters carbon on a local scale. Chris Jordan, NOAA fisheries biologist, says “beavers should be our national climate action plan.” Mark Vanhoenacker, in an article for slate.com, also thinks beavers should be our national mammal.
Beaver and Habitat
Rivers that are slower meander more and spread out, providing more water and habitat for animals and plants. Beaver activity reconnects isolated stream channels to the floodplain. This increases water absorption, water storage and raises animal and plant biodiversity, helping valley bottoms and rivers get back to what they looked like before humans began straightening and “channelizing” rivers for irrigation. Beavers are keystone species, providing habitat for songbirds, snow geese, otters, herons, pelicans, snakes, mink, raccoon, northern leopard frogs, sawflies, and trumpeter swans, among others. Even salmon benefit in the long run from beaver dams, which provide important slow water habitat for juveniles and improve overall salmon habitat.
Beaver Relocation
It seems like an easy solution to take beavers where they are a problem and put them where they aren’t. People are doing it, but it has its challenges. It’s expensive, takes a lot of work to trap, transport, and monitor beavers in their new sites. Beavers have to be relocated as a pair, or family, since they mate for life and the kits stay with the parents for two years. Beavers don’t always stay where you put them and they have many natural predators, so if they can’t make a pond and den fast and get underwater away from coyotes, wolves, and mountain lions, they are an easy target. Of course, not everybody has a soft spot for beavers, especially when beavers chew down people’s prized lilacs, fruit trees, and shade trees, drag all the deck furniture out onto their dam, or clog up expensive irrigation systems. In the 250 years since beaver were nearly trapped to extinction, a lot of that beaver habitat became farm and ranch land and so conflicts naturally ensued, most of which ended up with dead beavers. But beaver are nothing if not determined and driven by their instinct to dam up anything that sounds like running water. So as soon as one problem beaver is removed from a beaver-approved site, along comes another, and another, and another. As Sarah Koenigsberg says, "With climate change, we will have bigger storms and more hydrologic variability, but if we keep killing off beaver in the lowlands they’ll never get up to the mountains. if beavers can stay down below, new beavers that come will head upstream to the mountains where they need to be. This is why she helped form beavercoalition.org, empowering people to partner with beaver. To this end, there are tree protectors and various types of beaver flow devices with clever names like the “beaver deceiver,” or “beaver baffler” that allow beavers to do their thing while an underwater pipe keeps the water flowing (silently, so it doesn’t trigger beaver’s instinct to dam the pipe!) and keeps the pond from flooding into people’s yard and fields. Defenders of Wildlife helps people pay to install these devices so people can live with beaver rather than killing or relocating them.
Left: beaver release (credit Chris Canipe) | Right: beaver in a live-trap ready to be relocated (credit Aaron Hall)
To learn even more about beaver, follow the links below. Viva la Beavah!
Links
Defenders of Wildlife Links
Other Resources