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Human “Beaver Deceivers”

   Posted by heidi08 On April - 20 - 2008Comments Off on Human “Beaver Deceivers”

At the April 16th meeting the mayor invited Mary Tappel to rebut the subcommittee’s report (and if you haven’t read this morning’s Gazette article about this meeting you really should). Ms. Tappel referred to parts of it as mythology and said that the beavers were moving on because their food source was depleted. She added that 7 of the 7 flow devices she has seen installed have failed because the beavers simply relocated, and she included ours as the eighth. She had clearly visited this website and referred to the picture at the top of the kit eating blackberries as evidence of the food depletion because there was “no nutritional value in blackberries”. She had visited the dam early that morning and determined that the lodge was abandoned and that they had moved downstream. She proposed the city look into one town that had decided to deal with its beavers by keep them in a pit and charging admission.

Ms. Tappel’s history of involvement with beavers is complex at best, but she is certainly no advocate for our beavers. Her resume shows a BS in Botany with graduate coursework in water sciences. She serves part time on the State Waterboard, and has been involved with riparian restoration and beaver management. However, her name intially caught my attention with this quote in the Sacramento Bee, long before I ever knew about beavers in Alhambra Creek.

“But birth control isn’t the answer,” Tappel said. “Where you live-trap the male beaver and sterilize it, it’s complicated and expensive,” she said. “It puts stress on the animal, being captured and removed from the environment and held in captivity while the surgery occurs. What’s more, she said, the population growth resumes in just a few years.”

Aside from the obvious thought that perhaps killing a male in a conibear trap puts stress on the animal too (and if you’ve ever seen the horrific youtube footage showing how this can often mean slow drowning for an animal you know what I’m talking about) but aside from this, the statement about the population growth returning is simply bad science. Is she suggesting that it won’t return if the animals are killed? Would any other expert say that it was possible to successfully kill every single beaver in the area? Would any other expert deny that as the habitat recovers, the population will likely boom?

You may recall that she is the expert who the Gazette quoted on November 24th saying that “beavers breed for 50 years” and that the kits should be relocated at 10 months. This is untrue and unsound and I worked hard to document this in our report, [1],[2],[3]. After these misstatements were challenged she refused to appear before the subcommittee directly and answer questions but returned to meet with staff in private. She advised them, among other things, that as a way to control population, the adult male should be removed so that the mother would be forced to breed with one of her kits eventually.

I had thought that her presentation that night did everything required to discredit her argument, until I saw the substantial reporting by the press that gave weight to her position that the beavers were leaving after having depleted their food supply. This is simply not true and is another example of the media obligingly reporting myths that benefit those who want the beavers gone. Yesterday I spoke with person after person who had heard that news and believed it, so I thought I would address it here at beaver central.

  • Yes the beavers will leave some day, of their own accord, which is what beavers do all the time, but there is no evidence that this is happening now.
  • No, we don’t want to keep ours in a pit and charge admission.
  • Yes, our female is very pregnant and was just photographed working on the lodge.
  • No, beavers are not like the story of the baby Jesus, wandering off looking for a new residence right before delivery.
  • Yes, that particular kit was photograped eating blackberries in the summer at the height of available food season. That beaver just liked them and would go out of his way every day (passing up willow) to eat them.
  • Yes, the beavers have built a secondary dam which is not a “do-over” dam but more like a terrace which gives them greater feeding range.
  • No, the beavers have not run out of food. They are currently eating primarily tulle roots which they pull up, wash and crunch like carrots. Diet variety is essential for beaver health and all the beavers in the Delta survive on tulle because there are few trees. We still have willow for them to take, their coppicing will encourage growth eventually, and other trees can be added as needed through volunteer support. In discussion with Skip Lisle he said that apples and blackberries are a natural food source for beaver, they sometimes enjoy the sweetness. Beavers eat ferns, fennel, acorns, water plants and a wide range of foods besides willow. Check out the area near the secondary dam and you can see how close we are to running out of tulle.

There is a unique value in having a beaver population so entirely accessible that at least 30 people can view their habits every day. When a new behavior is observed, such as the kits building an addition to the lodge as was noted last week, it can be documented and discussed. Ms. Tappel’s observations, however experienced, are simply incorrect, and not relevant to our beavers. They certainly should have no more weight than the reports of the many people who see and photograph them every day.


[1] Steve Boyle & Stephanie Owens (2007) North American Beaver: A technical Conservation Assessment http://www.fs.fed.us/r2/projects/scp/assessments/northamericanbeaver.pdf

[2] Baker, B. W., and E. P. Hill. 2003. Beaver (Castor canadensis). Pages 288-310 in G. A. Feldhamer, B. C. Thompson, and J. A. Chapman, editors. Wild Mammals of North America: Biology, Management, and Conservation. Second Edition. The Johns Hopkins University Press, Baltimore, Maryland, USA.

[3] Collins TC (1976). Population characteristics and habitat relationships of beavers, Castor canadensis, in northwest Wyoming. Unpublished Ph.D. Dissertation, University of Wyoming, Laramie

Beaver Deceivers Meet The Press

   Posted by heidi08 On May - 6 - 2017Comments Off on Beaver Deceivers Meet The Press

Remember that Mill Creek beaver project in Washington? I heard from Ben about this yesterday, clarifying that it was a single walled pipe that went over the dam, not under. (Also he’ll make changes to link to our site soon, thank you very much.) Looks like they’re getting a lot more press this week, which is great.

Mill Creek tries new tactic to prevent beaver dams from flooding nearby roads

MILL CREEK, Wash. – Beavers in Penny Creek are in for a surprise.

In an attempt to solve a perpetual flooding issue that causes traffic delays, the City of Mill Creek has commissioned Beavers Northwest to build a “beaver deceiver.” The system of pipes has no formal name but the idea is to let beavers co-exist with humans and end the flooding issue.

This is a great story, and will someone please pinch me because I’m obviously dreaming at the public works quote?  Great work by our friends at Beavers NorthWest. This is really good coverage and fun to see. The reporter was obviously having a delightful time getting to use new tools that day, he even filmed the install with a go pro and tweeted about it, but you have to go to the article to see that, because I can’t embed it here.

Meanwhile, we’re off to the Mother’s day event at Wild Birds Unlimited in Pleasant hill. Always a fun day, and it will be a great chance for you to meet Gary Bogue and Joan Morris who inherited his column! (And for some unknown reason Chuck Todd is listed as a guest…I don’t exactly understand, will birds be on Meet the Press this sunday?) Jon and I are there the first half of the day, and Cheryl and Lory will see it close. Come see the bald eagle, stock up on bird seed and stop by and say Hi!

Skipping to the rescue

   Posted by heidi08 On October - 12 - 2017Comments Off on Skipping to the rescue

Well, the wine country fires are nearly as deadly as the Oakland Hills fires now, and have taken more homes and plenty more acreage. The entire town of Calistoga was evacuated last night and the two massive sidewalls of fire around Napa are probably going to meet up today, which is terrible news for our friends and the Tulocay beavers. To top it all off Cal-fire just announced a red flag warning for much of the entire state, which means the whole thing will get worse before it gets  better.

(I was vaguely remembering this morning how much people said they hated 2016, but they are going to remember it with fondness after this horrible year.)

DSC_7858The good news is that we heard from Rusty Cohn of Napa yesterday who is not missing but on vacation. We also heard from Susan Kirks of PLAN who said that Petaluma is terrified but holding steady. And our plucky little Martinez beavers have decided to forge ahead and rebuild one of the dams that were recently ripped out. Since there is fresh mud on the smallest dam, we can assume they must have repaired the larger too, even though we can’t see it. So we will take heart from their resilient spirits and fiddle on while Rome burns.

How one man tricked beavers and saved them — and roads — in the process

Knee-deep in muddy water, Skip Lisle wrestled with a metal fence, a key component of his invention, the Beaver Deceiver. On the morning of Sept. 29, deep in the woods of northeast Maine, Lisle pieced together the simple, durable device that he designed with one goal: trick the beavers, and in doing so, save the beavers.

CaptureConstructed on the upstream end of a road culvert, the device would prevent beavers from damming up the culvert and flooding the gravel road, something that is extremely common problem throughout the state.

“You hear about beavers being industrious and loving to work,” Lisle said. “That’s a myth. They’ll always choose the easiest damming site.”

Where humans see a gravel road with a culvert in it, beavers see a dirt dam with a tiny hole in it. As water rushes through the culvert, it calls to these natural builders, and their instinct is to “repair the dam,” block the culvert with sticks and mud so the area will flood, expanding their habitat. It’s what beavers do … unless you can somehow stop them.

That’s where the Beaver Deceiver comes in.

Maine is really a hotspot of beaver IQ at the moment. In the past two years I’ve covered stories as progressive as I’ve ever seen, and several that are equally backward – with hunting and trapping listed  as the only solution.  There is clearly some controversy going on there. But I’m hopeful with articles like these that beaver attitudes are moving in a good direction.

Growing up in rural Vermont in the 1970s, Lisle witnessed how beavers can rapidly change a landscape to benefit many other species of wildlife. On his family’s land, beavers constructed a dam across a waterway, creating a pond that expanded over the years, attracting a wide variety of animals to his backyard.

“There were so many animals using it, different species, and that stuck with me my whole life,” Lisle said.

When Lisle was bout 15 years old, the local beavers started damming up a culvert on a town road that ran through his family’s land. He realized that he needed to stop them or the road would soon be flooded. If someone else took action, the beavers would likely be killed. So he took charge and got creative.

truck“I actually stole some of my father’s old garden fence,” Lisle said, “and just built a crude fence in the culvert. And that’s when it all began.”

Constructing a fence around a culvert is the first step in building what Lisle would later call a Beaver Deceiver. But that invention was years in the making.

After receiving a bachelor’s degree in geography from Plymouth State University in New Hampshire, Lisle worked for ten years in construction, mainly doing painting and carpentry work. He then returned to school to earn a master’s degree in wildlife management from University of Maine in Orono. His thesis was on beavers, and more specifically, the wetland habitats they create.

“[Wildlife management] has always been my calling,” Lisle said. “I just didn’t answer it at first.”

Ahhh Skip! What a great article about a great man with a vision. Thanks for giving Maine such a lovely view of  how and why to do this. And thanks for being our hero when we needed it. If folks need proof that it works, give us a call. Martinez was happy to function as a ‘test case’.

Now there are two more fantastic beaver stories on my waiting list I’m eager to get to. Assuming I’m not too stricken by fire-grief tomorrow to do my job, tune in for a great story of saving urban beavers in Port Moody BC.