Archive for the ‘Beaver Behavior’ Category

Beavers Across the land

Posted by heidi08 On December - 13 - 2014ADD COMMENTS

Danvers SwampWalk under water

The problem is not with the walkway sinking into the muck, said George Saluto, a former Conservation Commission member who was the driving force behind the SwampWalk.

Instead, beaver activity, a surge of rainfall and a stretch of boardwalk built slightly lower than the rest of the lumber pathway has led to its being submerged

Two families of beavers have been building dams and blocking culverts and outflows, raising the level of the swamp, Saluto said. The southern section of the walkway was built, he added, when the area was not getting a lot of rain.

 “We are off on a new adventure,” Saluto said. “We are simply responding to a very productive — two very productive — families of beavers.

Well, there you have it. Yet another beaver bemoaning story out of Danvers MA, who brought us so many greatest hits this year, like the beaver they trapped but weren’t allowed to remove, and the huge developer who wanted everything but the beavers.

Now beavers (and rain and snow) are raising the water level and flooding parts of their swamp path. I guess they have two lodges so they’re sure its two families, although that would be very, very remarkable. Research tells us that different families need their own territory of at least 2 miles, but if the habitat’s very very rich, like those beavers in the far reaches of Canada who built the dam visible from space, they will share.

Gee, do you think this is extraordinary habitat? Or do you think they possibly got it wrong?

It took 10 years to plan, three years to build, and the collaboration of two towns. The walkway allows visitors to walk into the middle of the swamp, providing views of plants, birds, turtles and beaver dams that can’t be seen from the rail trail. There’s an observation deck with seating, too. A grand opening was held in May 2013.

When volunteers first started the northern section of the SwampWalk in 2010, the rainfall in March, April and May was 20 inches, Saluto said. Before the group started the southern section in 2012, the rainfall in February, March and April was 7 inches.

In the past three months, however — even before this week’s rainfall — Danvers received 13 inches of rain, Saluto said, 6 more than when the southern walkway was constructed. The southern section was built slightly lower than the northern section.

Instead of trying to install beaver deceivers, devices that allow water to flow through beaver dams and keep beavers at bay, the SwampWalk team has decided to raise the walkway’s elevation.

Well that’s interesting. I mean why protect the culverts when you have the money to rebuild the entire walkway? Why fix a flat when you can afford a whole new car? I would ask what they plan to do when the water level rises higher still, maybe because of the next 13 inches of rain or the beaver dam that blocks the culvert, but I won’t bother. I know what they’ll do. They’ll say “We tried a 6000 solution to save the beavers but that didn’t work, so we’re going to have to kill them.” Let’s mark our calendars. I think it will happen sometime in April 2015.

Got any spare change? They end the article with a request for donations.

Now we head west a bit across the United States for a story about beaver from Illinois, the state where the 84 year old man was hit in the head with a log after blowing up a beaver dam. IL  has never been a hot bed of progressive beaver understanding. I believe I once said of them

“Remember this is Illinois where a cynical person might say you could fit all their beaver appreciation and knowledge into a teaspoon and still have room leftover to sweeten your coffee”

So it’s nice to read at least a benevolent article about beaver from the state.

Trail leads to adventure

Not long ago, I was set for a nice long hike in a nearby park to work off stresses. I had my binoculars, camera, and a little snack to enjoy along the way.

At the trailhead is a small creek that runs underneath a rock outcropping. No sooner had I entered the trail, when I observed a newly-constructed beaver dam on the creek. I paused to take a look at it. This led to following a few of the “beaver runs” away from the stream to the trees they gnawed.

 I thought to myself that I should take a few pictures of the beaver dam, runs, and gnawed trees to go into the Lowell Park Nature Center. We have a beaver lodge there for children to explore. I thought I might construct a photo montage of beaver activity.

The article goes on to describe his watching deer and woodpeckers. What do you wanna bet that the next time he visits that beaver pond he’ll see more wildlife? If it’s still there he will.


Water, Water, everywhere

Posted by heidi08 On December - 12 - 20142 COMMENTS


CaptureDSCN0546Our beavers got three and a half inches of rain yesterday, but the flow device was still standing and there was a wet bump under the water indicating at least the mud part of the dam was still in place. I received an email from Robin in Napa which got much more rain than we did. She was heart broken by her visit to the DSCN0551beloved dam that was no longer visible under flooding. I of course said the usual things I say to console myself when these things happen. Beavers rebuild. The dam is probably partly still there underwater. Beavers have faced much harder things than this, have faith in them. And even in the hard flow their lodge was still standing, which was encouraging. Rusty went down a little later and could still see the outline of the dam underneath. (There art thou happy.) But beavers have hard jobs, there’s no denying it. There’s a reason they’re so busy. Our lazy lives are much easier by comparison. Imagine being the breadwinner, the contractor  the engineer, the flood control, and the public works department all at once.
outlineRecognize that familiar bump? It’s what we see every year after a washout,  and it means things aren’t as lost as you thought. I’m just thrilled that there are other souls in the world watching beaver dams in rain storms.

Jon just trotted down to look at our wet “bump” this morning, which he says is still visible. The level is too high to see if the filters in place, but he thinks it is. Jean took this movie just now with her phone. IMG_0628. From now on we can assume our beavers will be doing lots and lots of this.

beaver repairsNow if you have time before all the Christmas parties and you happen to be anywhere near Cape Cod you should really plan on attending this tonight.

 College Students to Present Environmental Science Research Results

The public is invited to attend a symposium featuring the research results of 21 undergraduate students who are participating in the Marine Biological Laboratory’s Semester in Environmental Sciences (SES) program. The symposium will be held from 8:20 AM to 3:30 PM on Friday, December 12, in the MBL’s Lillie Auditorium, 7 MBL Street, Woods Hole.

Sounds amazing. There’s a day worth of 15 minute presentations, but the last three look particularly interesting:

2:45-3:00 – Delaney Gibbs, EARLHAM COLLEGE
The effect of beaver ponds on the nutrient concentrations in the Cart Creek/Parker River Ecosystem within the Plum Island Estuary watershed
3:00-3:15 – Julia McMahon, DICKINSON COLLEGE
Influence of beavers on benthic community trophic structure in Cart Creek within the Plum Island Estuary watershed
3:15-3:30 -Jessie Moravek, NORTHWESTERN UNIVERSITY
The effects of beaver dams on nitrogen-mineralization and community structure in a forest ecosystem

 Oh, to be in Massachusetts now that beavers are the hot topic! I have written the presenters all individually and asked them to share their findings, hopefully we can find out soon. In the meantime keep an eye out for wet bumps in creeks near you!

Blame the Beaver Bombers!

Posted by heidi08 On December - 11 - 2014Comments Off

Back from the brink: See European beavers at work

Their destructive reputation seems to belie them, but beavers are now recognised as significant resources for carbon sequestration – the wood locked up in their dams and ponds accounts for a surprising amount of carbon.

 This may or may not influence a shadowy group of people known as “beaver bombers”. These, apparently, are eco-vigilantes who release beavers back into Britain.

Believe it or not, that phrase was used earlier in the year in a National Geographic article. Apparently no amount of mocking and derision can discourage it because here it is again in NewScientist, a global service housed in the UK. This, along with beaver raising temperatures for fish and beavers causing beaver-fever, and “You can’t get pregnant the first time” is the kind of totally inaccurate falsehood that we at Worth A Dam recognize as sadly incurable. We are never going to eliminate the rumor that fans have carpeted the land with beavers. We just aren’t.

How do I know it’s not true anyway?

In all the world, on all the continents, in all the cities, in all the land, have you EVER met any single human more insane about beavers than I am? Go ahead, I’ll wait while you think about that. Finished? Now I know for a fact that I haven’t ‘bombed’ or reintroduced beavers anywhere. So if the craziest beaver fan on the entire planet hasn’t done it, who could have?

beaver bombersCommunity support builds for wild beavers

As community support builds for Devon’s wild beavers, an oil painting of a Devon beaver has raised £700 for Devon Wildlife Trust’s work to keep the animals on the River Otter.

The canvas, by renowned east Devon wildlife artist Emma Bowring, was donated to the charity’s Devon’s Wild Beavers fundraising appeal. Support has also been forthcoming from Ottery St Mary schools, Exeter businesses – and even TV presenter Chris Packham.

 The aim of the appeal is to keep the wild beaver population on the River Otter by securing a licence from the government for a five- year monitoring project to assess the beavers’ impact on local landscapes, wildlife and communities.

10801570_1590048444550624_6264017908878124563_nThat really is a nice painting, very luxurious fur.  I was thinking last night about where beavers groom themselves when it’s pouring rain. Obviously there isn’t enough room in their lodges or holes for everyone to do it there. I was happy to remember that our beavers have plenty of bridges they can groom under which will give them cover for a few minutes. There’s something to be said about urban life.

 The presence of these animals might even influence artistic tastes. Dan added: “Emma Bowring told us that the most popular British animal for her commissions is the otter. If the government grants Devon Wildlife Trust the licence to keep Devon’s beavers in the wild, perhaps Emma will begin receiving requests for beaver paintings.”

Well, duh. Come look at the artwork in my dining room?

SRF 2016The agenda is out for 2015 Salmonid Restoration Conference in Santa Rosa. You should check it out. Just look at this workshop on restoring urban streams?! Maybe you want to come?

This Just In…

Posted by heidi08 On December - 6 - 2014Comments Off

Winter is Cold!

Beavers live in the water!

Trees are involved in someway!

News at 11:00!

Cache of sticks and a tail that’s thick

One fall a young beaver, probably a two-year-old kicked out by its parents, built a small lodge in the old mill pond below our house. On cold January days when temperatures were below zero, I looked at the snow-covered lodge and wondered if the beaver was still alive. But when the ice melted in late March, it was swimming around again.

First of all, beavers don’t get kicked out by their parents. (Your parents may very well have kicked you out, but beavers don’t) That’s the kind of ignorant myth that gets repeated at the very worst scout hikes. Second of all,  that headline is the kind of rhyme attempt I HATE.  (Like Clicket or Ticket.) Unless you’re writing for preschoolers or alzheimer patients thick and sticks don’t rhyme any more than moon and moo do. Besides,  this is a news headline, not a nursery story. So just cut it out.

Third, and this is my real point, I’m starting to get good and sick of these winter stories about  beavers living in frozen streams and surviving off a food cache. We KNOW already. Stop using column spaces to print pictures like this!

View inside a beaver lodge in winter.
(Photo: Adelaide Tyrol illustration)

You think I exaggerate?

Beavers in winter

Beavers seldom venture into the open air outside the lodge in winter, when ice covers their ponds, so for months a family of beavers breathes “indoor” air, using oxygen and generating carbon dioxide. Beaver lodges have underwater entrances, and mud seals the walls, so air exchange is effected through a ventilation hole in the roof. Apparently this roof vent is sufficient to keep carbon dioxide from building up and allow an influx of oxygen, because when researchers measured the levels of those gases inside an occupied lodge, they stayed nearly constant.

How about this story from Malibu recently?

 Furry Woodsmen Excel At Forestry

Among their remarkable traits is the flat, hairless paddle-like tail that allows beavers to prop themselves up while standing and whack the water in a highly effective, loud warning mechanism. Their dense undercoat of fur provides excellent insulation in water. Their lips close behind the huge, ever-growing front teeth for underwater chewing. They have self-stopping ears and nostrils for diving and large back feet with webbed toes, making them powerful swimmers. Two serrated claws on each hind foot are used for combing water repellant oil through their coat. Small, agile front fingers allow delicate handling of tiny objects.

Don’t get me wrong. I like for people to talk about beavers. I do it every day. We all should. But these articles advance the conversation not at all. These stories take up space and later when someone wants to write about real issues like beavers and salmon,  or frogs, or drought the managing editor will say, nooo we can’t run another beaver story. We did that one in December.

So just stop it. Think of your mother’s advice. And if you can’t say something important about beavers, don’t say anything at all.



The Scottish Beaver Trial Report

Posted by heidi08 On December - 5 - 2014Comments Off

  Scottish Beaver Trial publishes its final report

The Scottish Beaver Trial, the first formal reintroduction of a mammal ever to take place in the UK, has published its final report. The five-year-trial, at Knapdale forest, Argyll, is a partnership led by the Scottish Wildlife Trust and the Royal Zoological Society of Scotland.

 The first Norwegian beavers were released in Knapdale in 2009 and monitoring ended in May. This report will help ministers decide on the future of beavers in Scotland.


Now this is worth curling up and reading next to a good fire with a cup of hot chocolate. Or maybe Scotch. It’s a huge file and is taking forever to download but the entire thing is accessible here and you can count on me for some highights. I thought it was impressive but  Victor Clements just scoffed that its mostly presentation with little information. I was interested in details of the beavers lives.   Here’s the family tree, (ours is so much better!)

CaptureThe first thing that really caught my eye is that the trial site turned out not to be secure and maybe some of the beavers got away into the sea!! (Which our friends of the River Tay Beavers should find fascinating!) They installed a kind of flow device in the first dam and then realized it didn’t matter if the pond flooded! I was also interested to learn that two of their kits were predated, one by a fox and one probably by a large domestic dog. This surprises me not at all, but is worth remembering the next time someone says beavers don’t have predators.


Two kits were also found predated during the course of the Trial. One of these was a Dubh Loch kit found dead on 8 September 2011 in shallow water at the edge of a flooded track at the marshy eastern end of the loch by the SBT Field Officer while carrying out a routine field-sign survey. The cadaver was collected and taken for full post-mortem examination, which indicated that the beaver had been in good body condition but had died as a result of traumatic injuries to the head, possibly caused by a large predator. Although unconfirmed, it was felt by SBT staff that this could have been caused by a domestic dog–a diagnosis strengthened by later comparison with a kit killed by a fox. The second kit was found on Loch Linne by researchers from the University of Stirling, who were undertaking vegetation transects as part of their annual data collection. This kit was quite badly decomposed, and all internal organs were missing, so full post-mortem examination was not possible, though from the location of the puncture wound and marks on the bones it was presumed that this individual had been predated by a fox.

 Remember that these beavers got “injected, inspected, detected, dis-infected, neglected and selected.”They had Ear Tags, tail radios and GPS systems on their backs. They were weighed, sexed, measured and monitored at regular intervals. Their private moments were caught on film and they still managed to elude the researchers at times.  Dispersal, it seems was really hard to catch, and the first and second year it didn’t happen at all. Population density seemed to really effect behavior because where there was only one male at Dubh Loch the father (Bjornar) surprised everyone by mating with his own undisperssed offspring (Mille) who went on to have several kits. This is not totally unprecedented, but theu didn’t exactly issue a press release!

Capture23And speaking of press releases, there is an entire section on how they educated the media and the public for this monumental undertaking. They really included public support at every level and I am not at all surprised it worked for them. This is a great learning activity they did with the lower grades that has me thinking about the beaver festival! They made sure there was accessible, inviting viewing for the public Captu4reand encouraged visitors. They did what they could to bring the public along with them and make sure everyone understood where their tax dollars were going. There’s a very good reason why the Scottish Beaver Trial received an award for being the best Conservation Project of the year.


The report concludes with these exciting remarks:

The authors of this report, along with many others across Scotland, Wales and England, look forward to the coming months when a decision on the future of beavers in Scotland will be made. Perhaps one day we shall see the widespread return of this native species to our lochs, rivers and burns.

Worth A Dam welcomed the trial in 2009 and is proud of its conclusion in 2014. And when you watch this inspiring baptism think about how much bigger our festival is now.

A Call to Action

Posted by heidi08 On November - 22 - 2014Comments Off
Rett Davis
Published: Friday, November 21, 2014 at 05:28 PM.

Question: Coyotes howl, ducks quack, and deer snort. What sounds do beavers make?

Answer: The only sounds I have heard from a beaver are when they slap the water with their tail. It is a rare day that you walk up on beavers unnoticed. They have a keen sense of either hearing or sight. Your question prompted me to contact my wildlife biologist friends.  Both Harlan Hall and Jason Allen agreed they do not have a distinct call. When caught in a trap they will growl and hiss. But most animals do that. They did comment that puppy like sounds can be heard coming from their lodge. A lodge is where a beaver family dries out and sleeps. It is there that they are protected from the weather and their predators.  Swamps and all the animals that inhabit them surround their lodges.  You are welcome to pursue this answer. Let me know what you find out.

Raise your hand if you think Mr. Davis is correct? Well the poor man only talked to trappers for research so we probably shouldn’t blame him. We should invite him to come to Martinez from North Carolina and have a listen around June, when kits are whining away and yearlings are starting to get jealous. Then he will find out how very wrong this answer is.

Once upon a time, an entire age ago, I didn’t know beavers made noise either. And I thought they might possibly eat fish. I remember standing at Starbucks looking into the creek just after the city said they should be killed and thinking, do the people who want them dead even know about that noise? Have they ever heard it?

And then, if I let these beavers die, when will I ever hear that sound again?

So that plaintive whining became my call to action.  I thought, well I’d give the issue a weekend and try to save them. Then a week. And then, well you know the rest.

For beaver, though it hath no tongue, will speak

With most miraculous organ

Hurry! Only 12 days left to call WS liars!

Posted by heidi08 On November - 18 - 2014Comments Off

Well, I’m sure you’ll have plenty of other opportunities, but this is an important one. Before we get down to work and roll up our sleeves, let’s have dessert first.

Searching for beavers on the Quabbin Reservoir’s restricted Prescott Peninsula

About 20 DCR biologists and volunteers stomped to shake off the cold Sunday morning, standing in a ring outside a small shack on the Prescott Peninsula as Clark set the plan for the annual beaver survey. Teams would split off, tramp through the woods to follow their respective streams, take down data on any active beaver lodges, then return to the shack for lunch.

Beavers were non-existent in Massachusetts for more than a century due to hunting and trapping, plus elimination of habitat. After the valley was flooded in the late 1930s, the beavers returned.

Clark said that after the beavers came to the reservoir, the population followed a pattern typical of reintroduction — explosive growth, followed by a crash as the habitat is oversaturated, then a steady leveling off.

No way, are you suggesting that the population actually regulated itself? Without trapping? Even when the Massachusetts voters imposed new restrictions on trapping in 96 and the population was supposed to explode? This is pretty outlandish stuff. Just how long have you been collecting this spurious data?

The first Prescott survey was held in 1952. The survey has been annual since the early 1970s, and some of Sunday’s searchers have returned every year for 30-40 years.

Holy Guacamole Batman. You mean they have 62 years of data on beaver population? And the effect of conibear restriction is somewhere in the middle? You know a statistician worth his pocket calculator could easily whip those numbers into a regression analysis that disproves the accepted lie about beaver population exploding after the new rules were applied? You do know that, right?

Well, maybe the reporter got that wrong. He seemed really distracted by the meat balls. He does say that people aren’t normally allowed in the area because it’s in the watershed. Ahem. (News flash:Every place on this planet is part of a watershed. Just so you know.)


Everyone ready? It’s November 18th so that means you still have 12 days left to tell Wildlife Services that their rodent management plan is ridiculous, oblivious  of the environment or science, and barbaric in the extreme. But those are just my words. You’ll find your own. Here’s Mike Settel from Idaho talking about what’s needed.

In Wildlife Service’s newest justification for ridding us of beaver you can find that bit of humor and others in a recent request for public comment on Wildlife Service’s “Aquatic Rodent” EA for North Carolina.

Don’t attempt to e-mail your comments because, according to their deputy director for environmental compliance Alton Dunaway, receiving comments only by FAX and snail mail will “modernize” their public involvement process. I recommend Faxing comments to (919) 782-4159…However, an e-mail you may find useful is for that of the author, Barbara Schellinger. 

Even though it is a North Carolina document, the rationale proposed sets a precedent for mis-information and obfuscation regarding wildlife management. Please FAX your comments and request that WS includes non-lethal mitigation as beaver solutions, provide current data showing beaver harm salmonids, and prove that beaver dams increase sediment pollution (there are other spurious claims that are suspect or dated, but you should read those for yourselves). Regards, Mike

Thanks Mike for putting us on the right track. Remember, what they get away with in North Carolina will become precedent everywhere. I will share just a little bit of their ignorance, but you should really go read the report for yourself here:

The Wisconsin Department of Natural Resources guidelines for management of trout stream habitat stated that beaver dams are a major source of damage to trout streams (White and Brynildson 1967, Churchill 1980). Studies that are more recent have documented improvements to trout habitat upon removal of beaver dams. Avery (1992) found that wild brook trout populations improved significantly following the removal of beaver dams from tributaries of some streams. Species abundance, species distribution, and total biomass of non-salmonids also increased following the removal of beaver dams (Avery 1992).

Beaver dams may adversely affect stream ecosystems by increasing sedimentation in streams; thereby, affecting wildlife that depend on clear water such as certain species of fish and mussels. Stagnant water impounded by beaver dams can increase the temperature of water impounded upstream of the dam, which can negatively affect aquatic organisms. Beaver dams can also act as barriers that inhibit movement of aquatic organisms and prevent the migration of fish to spawning areas.

Wow. Give it up for the USDA and author Barbara Schelllinger who was willing to dig back through 47 years of research to find the  completely bogus paper she just knew to be true! This woman is no slacker when it comes to bravely lying about beavers. Good lord, the letter almost writes itself. Although I personally feel that Issue 7 deserves the lion’s share of our attention.

Therefore, the breaching or removal of a beaver dam could result in the degrading or removal of a wetland, if wetland characteristics exist at a location where a beaver dam occurs. The preexisting habitat (prior to the building of the dam) and the altered habitat (areas flooded by impounded water) have different ecological values to the fish and wildlife native to the area. Some species may benefit by the addition of a beaver dam that creates a wetland, while the presence of some species of wildlife may decline. For example, darters listed as federally endangered require fast moving waters over gravel or cobble beds, which beaver dams can eliminate; thus, reducing the availability of habitat. In areas where bottomland forests were flooded by beaver dams, a change in species composition could occur over time as trees die. Flooding often kills hardwood trees, especially when flooding persists for extended periods, as soils become saturated. Conversely, beaver dams could be beneficial to some wildlife, such as river otter, neotropical migratory birds, and waterfowl that require aquatic habitats.

beaver in barDingDingDing! I found the opening! (Well, one of many actually.)  See in their effort to say “it’s a wash, really” beaver dams HELP some species sure, but they HARM others. So getting rid of them is a zero sum game with totally justifiable consequences. Just take the darter for instance!


Maybe we’re the only ones that remember there’s this famous case from Alabama in 2008 where the city of Birmingham was sued by The Department of Conservation and Natural Resources (among others) for upwards of a million dollars over removing this beaver dam that was protecting  thousands of the rare endangered watercress darters. In the end the case cost the city some 4,000,000 dollars and dragged  out in court over 4 years. Am I ringing any bells, does this sound vaguely familiar?

The city “knew or should have known that removing a beaver dam and surrounding natural structures would potentially disrupt the water level of the Basin and its inhabitants,” the agency claims.

CaptureDam [sic],  this is gonna be fun. If you want to share your letters, send them to me and I’ll make sure they’re visible. I’m sure WS is hoping they can make it all the way to November 30th without hearing from you. Let’s disappoint them, shall we?