Because the beaver isn't just an animal; it's an ecosystem!

The Martinez Beavers

Category: Beaver Anatomy

There’s a nice story this morning about watching beaver activity as we head towards winter from Marshall Helmberger of Minnesota.

The busy season

It’s the busy season at our neighborhood beaver pond, as the locals prepare for the impending season of scarcity. The signs of activity are everywhere, particularly along the pond’s edges, where the resident beavers have recently felled at least a couple dozen youngish aspen to put away for the winter.

It all seems pretty familiar. We fill our own wood sheds and stock the pantry and freezer with the season’s produce, and the beavers do pretty much the same. This time of year, the beavers are cutting aspen and willow and storing the branches and smaller trunks in a huge cache under the water, just outside one of their two lodges. These caches are readily visible this time of year— since some of the smaller limbs often stick out from the water— and are an easy way to tell if beavers are planning to spend the winter in any given lodge. Beaver lodges can last for decades and they can fall in and out of use over the years, so this time of year I always look for the telltale signs of a fully-stocked pantry to determine if a lodge is currently active.

Once the ice arrives on the beaver pond, which could happen this coming week given our recent cool down, the beavers will be locked in for the winter. They’ll live the next several months within their dark lodge, only occasionally venturing out of one of their underwater exits to grab a bite. While their pantry of sticks is their primary source of winter food, they also store large amounts of fat in their tails this time of year, which they will also rely on during the winter months. A beaver’s tail, in the fall, is usually substantially larger that it will be when the beavers emerge from their lodges next April or May.

Don’t you wonder what that’s like? Or which family member you like enough to be stuck in a closet with for three months out of the year? I’ve been fairly lucky in terms of opportunities to see beavers, but I will always regret not getting to see this. The tell tale food stash and the signs of beavers cracking through the ice to get whatever they can forage. I’m not entirely sure I believe the last sentence about their tails being smaller in May, but I bet our beaver size has a lot to do with not needing to live off reserves. Marshall does a nice job in this piece by capturing the urgency of late fall.

Speaking of beaver authors, I heard from author Ben Goldfarb that he just had a very enlightening chat with our city council man Mark Ross about the beaver story. He said it was helpful to get the city perspective on the story.  (I would just LOVE to be a fly on the wall for that conversation, wouldn’t you?) I bet there were lots of fears of flooding and very few honest concern about voters in his tale.

Meanwhile it you want to get the story from the other perspective, why not listen to the talk I did Tuesday from the convenience of your desktop. I really appreciate fur-bearer defenders for getting this online and sending me the link! This will give the whole story plus some never before disclosed secrets from behind the scenes. (You can thank them for doing tall his by dropping 5$ in their donation jar.) I just realized that the anniversary of that big November meeting is a week after halloween! Perfect timing to hear it all again or for the first time. I think my voices sounds lower, what do you think?

I thought I’d share a little about the odds and ends that followed my last few postings. One was about the water week events in Whatcom WA. You might remember that the paper said there’d be a showing of the film “Beavers in the Ecosystem” which I wanted to find out about. Turns out the paper got it wrong, it wasn’t actually a film but an event lead by the North Sound Baykeeper for Clean Water Services, Lee First. I got in touch with Lee through our friend Ben Dittbrenner of Beavers NorthWest. Seems Lee contacted Ben looking for properties with beavers on them that might allow a tour for his guided event and talk.

Lee impressed me right away with this response to my letter:

Hi Heidi, it’s not a film, it’s a site tour.  I’ll take photos during the tour, and I’ll probably write a little story about the tour.  I love beavers!

As far as I know there are two people in all the world who collect a city salary and love beavers. And now I know both of them! There surely aren’t any such people in Martinez.

The other follow up comes from my column on the story accusing the Welsh beavers of ruining the sequel film date. I got an email from Alicia Leow-Dyke of the Welsh Beaver Project thanking me for the graphic.

movie starThank you Heidi, that means a lot. I was so annoyed when I read the original article, beavers being blamed without any evidence! Someone has to stick up for them!  I love the graphic!! That’s brilliant! Would it be OK for me to use that graphic in our talks or on our website? I also love the beaver cushion that has been sent to you from the Ukraine. I am going to have to buy one for myself!

best baby everI told her of course she could use it, and showed her the photo of our kit where it’s from. Graphic Designer Libby Corliss didn’t work with us long, but the silhouettes she made that summer from Cheryl’s photos have been a lasting treasure I rely on again and again.

Onto the treats of the day, this time Parks and Recreation Department of Calgary, which is about 400 miles north of Montana across the Canadian border. Seems they just updated their beaver webpage and WOW they did an amazing job. Even when I read it the third time this morning, I was still surprised and impressed.


Beavers have found an inviting home in Calgary, with its two rivers, abundant green space, and lack of predators. In recent years, their population has grown, with lodges in various locations along the Bow and Elbow rivers, in storm water ponds and wetlands.

Beavers are good for our environment

Beavers play an important ecological role in Calgary’s waterways. Their dams can create ponds that provide habitat for other wildlife and help surrounding vegetation to flourish. The ponds and wetlands are very good at storing water, and can help reduce the effects of smaller floods and hold water during droughts.

Water flowing through dammed areas is naturally purified, and after a dam has broken, fertilizer created from the decomposing material in the dam will spread downstream.

I promise I haven’t embellished this or edited to make it look better. This is the ACTUAL website for Calgary and it starts by describing how lucky we are to have them. Then it gets around to talking about problems, but in a pretty reasonable way.

Beavers also present some challenges

Because conditions are so good, Calgary’s beaver population has grown in recent years. This can cause problems for our forested areas, infrastructure and property, and the beavers themselves.

A single adult beaver can cut down about 200 trees in a year. With each lodge housing four to six beavers, wooded areas can be devastated in a short period of time. This is harmful to other wildlife that rely on the trees for habitat. Beaver dams can also cause flooding that affects property, and in some cases, can damage storm drains and weirs that can be very expensive to repair.

Okay, that’s most reasonable. People can legitimately have concerns about these animals. There’s only a single sentence I take issue with.

“Without natural predators, beaver populations can grow to be unsustainable.”

Ahh Calgary, you were doing so well up until them. Did you never read that beavers were territorial? Did you never think that when the streams were full of beavers the new ones would have to look elsewhere for a place to call their own? I would be disappointed in them,  but they quickly redeemed themselves.

The City’s approach to beaver management

The City’s practice is to try and strike a balance between health of the surrounding areas and the wellbeing of the beavers.

When required, The City uses different measures to protect trees and property to make our river parks unappealing to beavers. Depending on the situation, we may use a combination of the following:

  • Placing metal wiring around tree trunks.
  • Planting varieties of trees along the shore that are less palatable.
  • Placing under-dam drains to control water levels.


We consider all other options before turning to trapping. However, in some cases it is required. When we do remove beavers, we use traps that are designed to kill instantly. The traps are placed under water for the protection of dogs, park users and other wildlife, and are checked daily.

There’s a final paragraph on why they can’t relocate beavers that are causing issues instead of trapping them, but honestly this is ALL I WISH from any city beaver management policy. Protect trees. Plant Willow. Install flow devices.

Consider it my version of “Eat. Pray. Love.”

If every city tried to do these things before trapping I would be over the moon with joy. Honestly, this is the best and most sensibly proactive policy I have ever read.

They even have a video teaching how to wrap trees. Be still my heart.

I expect a mass exodus of beaver supporters moving to Calgary right away. Honestly, my bags are nearly packed.

One more present for Heidi in the Odds and Ends category. This lovely website I came across in my travels is called, with the actual tagline “A friendly place to post sightings of beaver-like mammals” which she dubs BLM’s.


Beaver Like Mammal.

Everyone wants to make a contribution to society, to leave their own little mark on the world. This website is my mark. It provides a public space where people can post sightings of beaver-like mammals (BLMs). Did you spot a BLM at the corner of 10th Street and West Main? Does a BLM emerge from the bushes by your back porch every evening around 6pm? Did you catch a glimpse of a BLM out of your car window on the way home on Thursday night? Submit your sighting to!

There is a page for submitting a sighting and your observation will be listed by your state. Most of the entries she has look like woodchucks with the occasional squirrel. I don’t see any actual beavers since back in 2007. But she definitely gave me a gift.

From now on, the next photo of a nutria I see on a news article about beavers I’m calling it a BLM.

tippytoe beaverWhat did we learn with our event in American Canyon yesterday? We learned that miniature horses are cute. That children (and two adults) love to use the new watercolor markers and make really cute beavers. And that parents cheat and tell their children ‘higher, lower, a little to the left’ when you have them help with pin the beaver on the keystone.

We also learned that American Canyon visitors were a wonderfully diverse mix and parents were very well informed and patient with their children. One father helpfully told us that ‘Keystone’ in Spanish was “Piedra Clave” We learned our new banner was cute and well received, and that at least one federally paid forest service ranger can’t tell a beaver footprint from a badger.


(They had an interactive game, match the footprint with the animal, where the answer for beaver was obviously wrong. When Cheryl gently explained it to them they said ‘but that’s the way it’s labeled‘ and were reluctant to change it.) Since it’s probably a USFS issued game and everyone uses it, do  you think that means the entire forest service can’t tell a beaver footprint from a badger?

Well at least you will be able to.


I will have photos of our day soon, but Cheryl is taking the morning off after working Saturday at the Sonoma event and Sunday at American Canyon. Shhh, Let’s let her sleep in.

Time to make fun of the Colorado project to restore open space by tearing down actual trees and replacing them with concrete trees (no really!) and ripping out an actual beaver dam to replace it with a BDA. Because, progress!

Robert Brakenridge: Boulder County Parks and Open Space has some explaining to do

Most of this property belongs to the public as county open space. However, what is being rebuilt will actually be less”resilient” to coming floods, not more. The process is destroying the existing natural floodplain, in order to restore it.

In May, an experienced birder took groups up the Old St. Vrain road on several weekends and the floodplain wildlife was incredible. The vegetation was already high, tree species were becoming established, there were small local wetland areas: exactly how nature intends floodplains to be, exactly what slows flooding as well. The vegetation and animal diversity were becoming richer with each year. Now much of this has been stripped literally down to bare rock. Old dead cottonwoods that should have been left are gone. Floodplain soils, gone. Raptor habitat, gone. Prime bear foraging areas (and bears), gone. This is public land, expressly put aside to preserve these habitats.

Indeed, the whole concept of “restoring” such an already-beautiful river and floodplain to some idealized “natural” state could have been seen, by the responsible regulatory authorities, by the county, and by SVCC, as plainly inappropriate to start with. Few would argue with local measures to protect dwellings, or to protect public utilities or highways. But employing the same overall river restoration strategy used for urbanized rivers on this relatively natural public land, land that was already restoring itself, is completely inappropriate. Think I am exaggerating? Quoting from the South St. Vrain Design: “Beaver Dam Analogues. Some of the project area prior to the flood was known to hold otter and beaver in small ponds throughout the corridor. A couple of historic beaver ponds were destroyed in the 2013 flood that provided a great wealth of habitat and biodiversity thorough the area. These beaver ponds will be reproduced with the use of Beaver Dam Analogues (BDA) installed as part of this project. BDAs are man-made structures that mimic beaver dams that are found in nature.” This is a very public waste of public funds; the project itself drove away what beavers may have remained.

The project has pulled down giant old dead cottonwoods (important bird habitat): so is now going to erect a few artificial trees. The heavy equipment is stripping and grading the floodplain and channel, and then, because this is an “ecological” design, the same land is going to be roughened up with built riffles and logs dug into the ground to produce local pools and simulate nature. This kind of plan is appropriate when starting with a ruined urban channel. But in this case, the river and floodplain after the flood were more natural than most any other channel and floodplain in the region. For what reasons are they being subjected to this treatment?

Well, I know nothing about this project in particular, but I do know that is a wonderfully well-written letter Professor Robert Brakenridge of Colorado University. And I do know something of the insanity that happens when cities decide to ‘beautify’ and restore rivers by using heavy equipment and ripping the banks and the trees.  When man thinks he can outplan nature he is usually wrong.

But by way of comfort I will offer this. Once upon a time, Martinez ripped up it’s creek to protect from flooding and paved the walls with concrete and unnatural surfaces. They shaved the banks and squeezed sheetpile in to keep them from eroding. To make up for the terrible impact they had on the once-natural creek they dedicated one tiny spot to appearing ‘natural’ and planted trees along the newly decimated bank.

historic sheetpile

6 years later our beaver moved into that VERY spot and built a dam that attracted such wildlife it became one of the most vibrant parts of the city. Be patient.

Apparently San Jose’s beavers get a mural too!

Family of beavers moves to Los Gatos Creek for first time in 170 years

Remember this is for the CREEK coalition, so the idea of a beaver is less important than the idea of water, which I think is accurately reflected in this toothy mural. But I love the size of this mural. Apparently they do nothing in half measures in San Jose.

Do you want to tell them the truth about beaver teeth, or shall I? Either way we’ll get a chance to talk it over with them at the festival, because they’ll be booth 37 and handing out beaver tattoos! Here are the flags for each participating booth I made yesterday.

tattoo flagsIn the mean time let’s appreciate the lovely photo by Cheryl Reynolds that was included with permission in this month’s issue of the Canadian magazine “Saltscapes“. It has a modestly nice article about beavers authored by Bob Bancroft.  The current issue is only available to subscribers but they mailed us a copy as a courtesy. It’s mostly about the history and biology, but does a little work learning about the benefits they provide -(then goes on to promptly list all the mosquitoes they cause, so it’s not the best) – but it does have Cheryl’s name and OUR WEBSITE so truly curious minds can come learn the truth if they want. Here’s the photo and I scanned the article. Article_0048Article_0049



WILD ALASKA LIVE | Exploring a Beaver Dam | PBS

Just because it’s called ‘educational programming’ doesn’t mean it makes you any smarter. GRR! Wild Alaska had so much potential and mentions how important ponds are to other wildlife, but it decided to emphasize instead that salmon HATE beaver dams.  (At least it clearly shows them jumping over.) Quick, to the bat beaver mobile! Leave a comment so they read some research that shows how crucial beavers are to those precious fish.

Meanwhile there’s plenty of good news from beaver central, with a nice beaver article published yesterday in the Mercury News, written by our old friend Sam Richards. The nicely-written plug even links to the festival website!

Beavers or not, annual Martinez festival happens Aug. 5

MARTINEZ — There probably aren’t any beavers in Alhambra Creek as you read this, but there definitely will be a 10th annual Beaver Festival, to honor both the paddle-tail swimmers that put the city in the national news in 2007 and 2008, and the creek environmental experts say benefited greatly from the beavers’ presence.

This year’s festival runs from 11 a.m. to 4 p.m. Saturday, Aug. 5, at what’s come to be known as “Beaver Park,” the grassy plaza off Marina Vista adjacent to Alhambra Creek, near the Amtrak station.

The festival boasts environmental booths and displays from groups in five counties, live music, a wildlife-centered silent auction and children’s activities that combine craft-making with environmental learning.

Festival participants can learn everything they need to know, through a kid-friendly illustrated “beaver wall” showing the process, and a costumed beaver expert explaining on stage the good works that beavers do to help the overall ecology where they live.

Brock Dolman of the Sonoma County-based Occidental Arts and Ecology Center’s Water Institute will give a presentation about the beaver’s worth in an ecosystem. That group leads a “Bring Back the Beavers Campaign” to encourage their return to more local creeks.

Award-winning author Ben Goldfarb will be on hand to discuss his upcoming book about beavers, and other experts will be on hand to offer their views.

The festival is free, and decidedly family-friendly. For more in formation, click here

Wonderful! He did a great job of sifting through my tome of a press release and finding the important bits. (There’s always too much to say or explain. I have a pith problem, I admit it.) I’m glad that he talked about the importance of Brock’s presentation and the “Bring Back Beavers Campaign” and even happier he mentioned Ben Golfarb’s upcoming book. But I love decidedly family-friendly the best, and that’s why it’s in blue. It makes us sound soo cheerful and appealing.We’re also expecting an article from Jennifer Shaw and the Gazette, so with any luck at all I won’t be the only one there.

BTW if you haven’t seen the festival page yet you should check it out.