Those trampy American Beavers….

   Posted by heidi08 On March - 1 - 2015ADD COMMENTS

Canadians too. Apparently only the european beaver knows how to make a marriage work.

CaptureBeavers pair up for life and never cheat

European beavers are truly monogamous, but the same cannot be said of their North American counterparts

Most animals aren’t the marrying kind. Less than five percent are believed to pair together for life, and even if they do stay together they do plenty of cheating.  But not European beavers. Not only do they pair up for life, a new genetic analysis shows that they are faithful to each other.

 A team led by Pavel Munclinger from Charles University in Prague, Czech Republic took samples from several European beaver colonies living in the Kirov region of Russia. They then analysed the genetic relationships among family groups.

 In every colony, all the offspring belonged to both of the parents. None of them had been fathered by males from elsewhere.

The same cannot be said for their American counterparts. North American beavers are known to mate with beavers other than their bonded partners.

 They cheat a lot. In 2008, researchers discovered that the “father” of a pair of young was unrelated to at least one of them about half of the time.

I knew all this monogamy business was a smokescreen! How many times have I been watching our beavers and seen mom bat her come-hither eyes at the nearest woody offering! (There’s a reason the word beaver has another meaning ya know…) We read this particular research they’re referring too back in 2008 in preparation for our historic prevalence paper. The authors referred to it as “opportunistic monogomy” and Rickipedia quipped that the term describes most males of the human species too. Ha.

Cheating does have its advantages. If a mother mates with a healthier male than her main partner, she can pass better genes onto her young.

 But there are also advantages to staying loyal. “Genetic monogamy lowers the risk of parasite transmission,” says Munclinger.

 ”It also lowers the risk of partner desertion, which is very important in species with extensive parental care of both sexes.”

 Staying faithful seems to serve the European beavers well. Their populations have been climbing in areas of the UK where they have been reintroduced.

It’s good that this news is being lauded in the British Press. They need another reason to like beavers and being told ‘theirs are better’ is a great way to convince the holdouts. In  a more sober consideration you have to wonder whether population density matters. And whether  having very little competition affects how faithful beavers chose to be. Most of Europe is as crammed with beaver as it is with people now and those beavers don’t cheat apparently. Our population is decimated and our beavers mate with anything they can get. Maybe the facts are related. Didn’t a pair from the (no beavers for 500 years) Scottish beaver trial hook up with other beavers?

We  American beaver-lovers will just continue being content with their slutty ways until the population gets fuller, I guess.

And in case you need more praises sung for beavers, here’s a fun reminder from Fairbanks Alaska

Rodents are remarkable creatures, not pests

If you only think of rodents as pests, you are missing out. One reason these animals are misunderstood is because there are so many of them. More, in fact, than any other kind of mammal, but they play an important role in the ecosystem.“

 Some of these rodents are referred to by ecologists as indicator species,” Nations says, “because they indicate the health of an ecosystem.”

 Another example is the role that beavers play in creating wetlands that are used by many bird species. Beaver ponds also can be convenient places to spot moose and muskrats are known to take up residence in beaver lodges, as well.

Theresa Baker ends the nice article by suggesting kids build a ‘rodent collection’ in their home, you know a clay porcupine with toothpick spines etc. Good idea, and I would definitely include one of these:


Inspired by the fact that a beaver kit is shaped exactly like a peanut. Peppercorn nose, lentil ears, black mustard seed eyes and pumpkin seed tail set in macaroni noodle, Worth A Dam original



Some good beaver news that might pass unnoticed…

   Posted by heidi08 On February - 28 - 2015ADD COMMENTS

The first is a new article from Rochestor Minnesota where the outdoor reporter has surprisingly nice things to say about beaver.

 Chris Kolbert: Beavers create havens for trout — and anglers


  Beaver ponds are one of my favorite places to fish trout, and studies have shown that they can enhance trout and salmon populations. The large rodents are engineering geniuses, building dams to deepen the water, creating habitat that allows them to survive harsh winters.

 Just upstream, a beaver lodge, made of logs and branches, was built into the stream bank to create an impenetrable fortress in which the animals could live. As is typical for beavers, a food bed of freshly cut saplings was buried in the pond, with only the tips of the branches rising above the ice.

 I moved out of the willows and cast into a shallow riffle below the beaver dam. As the line passed a large boulder, another fish picked up the bait. This time, it was a spunky 12-inch brook trout that gobbled up the nightcrawler.

 The mid-day sun beamed down on the water as I turned back. For a short time at least, I’d cured my case of cabin fever — and I had a few beavers to thank for that.

The photo is a dam on a trout stream in northeast Iowa creates a deep pool that’s perfect for trout. Beaver dams can cause problems for landowners, but they can be an angler’s best friend.

(Except in Scotland and Wisconsin where they are terrified of them.)

Thanks Chris for reminding us of yet ANOTHER reason to appreciate beavers. We always need more. Although I won’t post this article anywhere near our beaver dam, because the last thing we need is a beaver snagged by some fishing tackle or tangled in line!

More good news from Ohio because Sharon Brown sent me the article on Mason we missed when I was away conferencing.

Controversy Builds Around Beaver Dams

ONow there’s a story you don’t read every day from Ohio. They are still hard at work deciding if they can stand learning such new things and co-existing with beavers, but I’m thinking with BWW on their side and some very concerned residents they have a dam good shot at success! Go here to read the full article with has only 1 or 2 things I’m scratching my head over.

For example it says there are “30 beaver families” in this park. Where on earth does that stat come from? Do they mean 30 dams? Hopefully Owen and Sharon will explain that one dam doesn’t equal one family. Our family maintained as many as four at one time. People have all kinds of complicated statistical methods to infer beaver population, but honestly. The only way you’re going to know for sure is just by watching.

And remember, it was Scott Stolensberg of Ohio’s perfect Glass Farm Beaver photo that gave me permission to use his photo and do this.

Keystone Beaver Arch

Photo by Scott Stolensberg, artwork by Worth A Dam

Now I’m off to record a post-conference interview with Furbearer Defender Radio, to talk about what was learned at the State of the Beaver. Hopefully it will be up and share-able sometime soon. Wish me luck!


Message Delivery

   Posted by heidi08 On February - 27 - 2015ADD COMMENTS

Indiana University researcher reports that isolated wetlands matter a great deal – just not the things that make and maintain them.

Isolated wetlands have significant impact on water quality

Geographically isolated wetlands play an outsized role in providing clean water and other environmental benefits even though they may lack the regulatory protections of other wetlands, according to an article by Indiana University researchers and colleagues.

 Given those benefits, the authors argue, decision-makers should assume that isolated wetlands are critical for protecting aquatic systems, and the burden of proof should be on those who argue on a case-by-case basis that individual wetlands need not be protected.

 ”Geographically isolated wetlands provide important benefits such as sediment and carbon retention, nutrient transformation and water-quality improvement, all of which are critical for maintaining water quality,” said lead author John M. Marton, assistant scientist at the IU Bloomington School of Public and Environmental Affairs. “We demonstrate that continued loss of these wetlands would likely cause serious harm to North American waters.”

 Yes it’s true, wetlands are really important, especially when they’re in unconnected areas that aren’t attached to other wetlands.  Our top notch researchers think they’re so important that people should be prevented from ripping out those wetlands. And the government should play a roll in making them.

We don’t have the foggiest idea of how those wetlands get there, but we know they’re important.

Yes, webs are important but spiders don’t matter at all, nests are invaluable but we aren’t sure what makes them. and eggs are vital but who cares about chickens?


Oh alright, maybe you’re getting the football very close to the end zone and it’s up to some other researcher or environmental attorney to get it over the line. Certainly this lays a certain foundation. And I would know JUST where to look for argument if I were trying to save beaver in Indiana.

Citing research literature, the authors say geographically isolated wetlands are highly effective “biogeochemical reactors” that improve water quality. They often retain water longer than protected waters, such as streams and wetlands that are directly connected to navigable water. And they have a higher ratio of perimeter to area, allowing more opportunities for reactions to take place.


This morning a quick update from beaver friend Lisa Owens Viani, the founder of RATS, who guest posted this article on 10,000 birds. Apparently the raptor-killing fiends of the world have come up with the excellent idea to name their new rat poison “HAWK”, because you know, hawks kill rats too, get it?

22Hawk.22-2-400x280It takes a lot of nerve—or something that can’t be printed here—to name your rat poison after the animals that so effectively and efficiently control rodents but that are also being poisoned—as “non target” animals—by your product. The label on Motomco/Bell Lab’s rodenticide “Hawk” even sports a drawing of a hawk getting ready to pounce. But “Hawk”’s active ingredient, a deadly second-generation anticoagulant, bromadialone, has been implicated in the deaths of Red-tailed Hawks, Red-shouldered Hawks, Cooper’s Hawks, and other raptors: American Kestrels, Barn Owls, Golden Eagles, Great Horned Owls, and Turkey Vultures. These birds are being poisoned after eating rodents that have been poisoned by products like “Hawk.”

You can read the entire article here. I told Lisa not to worry because this was such a tone deaf marketing decision they could easily turn it to their advantage. Instead of writing outraged letters or presenting them with a cease and desist letter. send the most flowery thank you card you can find, and say how much you appreciate their help in  linking rat poison to hawks, reminding every single buyer who the real victims of their products are. That kind of branding is invaluable. It’s hard work doing it yourself and billboards are very expensive.

Ask when their similar products of OWL or BOBCAT will go on the market, and say you appreciate their help in this matter. If you thank them sincerely enough, I said, that label will disappear.


Magical beaver day

   Posted by heidi08 On February - 26 - 2015ADD COMMENTS

Yesterday we had arranged a meeting between two Watershed Stewards Program Americorp interns and the city engineer of Martinez to talk about planting willow in the beaver habitat. It all became possible after my presentation at the San Francisco water board in December. Rebecca and Corie took Amtrak out from Oakland and we gave them a tour of the planting areas and beaver dam before taking them to the meeting. On the way we came across the most darling little beaver chews from our 2014 kit that we presented as souvenirs (along with hats, which were much appreciated, as you can see).

Desktop3Then we sat down to what we expected to be a challenging meeting. Historically it has not been simple to negotiate with the city to put trees in the beaver habitat. (Take from that what you will-it’s almost like they don’t want the beavers to stay!) But we were hopeful that having some professionals in uniform might make it easier. We talked a little about the areas we wanted to plant, and then discussed the ideas I had encountered regarding fascines at the beaver conference, which prompted our interns to talk about their recent projects at Baxter and Strawberry Creek where they had used fascines of both willow and dogwood.

We talked about timing and their experience, and then the city engineer said he would handle things with the council and with Fish and Game and we could get the project moving within two weeks.(!) They would do the planting and get the willow cuttings, and encourage some colleagues to help out on the day. We promised to reward everyone with hats if they did!  And then the meeting was over. Approximately 15 glorious minutes after it started.

No, really.

Jon and I were in varied states of amazement. To say that was not the reception we’d been expecting is a significant understatement. But I swear it really happened. And we are on board to get willow in the ground before the middle of March. Riley will help arrange for them to harvest it from wildcat canyon in Berkeley, and they will make the fascines and plant them. (Just pray that it rains SOMETIME along the way.) And thank you to Riley for sending these hardworking city-soothers our way. This video will teach you about what facines are, and this one could show you the magical way they work in less than 3 weeks! Our fascines will be buried in the unrocky bank.

Still don’t believe it? The day needs more incredulity, so I’m going to show you the very best beaver news out of Canada that was ever filmed. I can’t find a date on this story, and can’t embed it so you will need to perform the onerous labor of clicking on it and watching an ad, but trust me, even if you never trusted me before and never will again,  it’s worth it.

CaptureStarving beavers kept alive by couple after dam destroyed

Don’t you LOVE these people? Someone give them a bag of sweet potatoes right away!

Fnally I got a delightful email from Rusty in Napa yesterday because the beaver pond in Tulocay creek was visited by a whopping 5 pairs of hooded mergansers that evening. He was surprised how people shy they were in such an urban setting. But very kindly shared these photos. The beautiful one is the boy, and the rusty hairdo is the female. Enjoy.

HM napa

Hooded Merganser at Tulocay Creek – Rusty Cohn

hmpairs Napa

Hooded Merganser pairs – Rusty Cohn


Sometimes traffic can do what trapping cannot

   Posted by heidi08 On February - 25 - 2015ADD COMMENTS

CaptureDam shame: Bike path beaver may have bitten the dust

THEO DOUGLAS The Bakersfield Californian 

 The body of a large paddle-tailed rodent was found early Tuesday in the traffic lanes of southbound Mohawk Street north of Truxtun Avenue, suggesting Bakersfield’s fabled bike path beaver — scourge of local saplings — may have died.

 Exact identification will be difficult for although the decedent appeared in excellent condition, conclusively proving its origin will be nearly impossible for obvious reasons.

 Its time in these parts may date back about 15 years, according to residents who have told The Californian they remembered it in the southwest before the Park at Riverwalk was built.

 A relatively harmonious co-existence with city officials and bike path users was shattered in 2007, when — for reasons best known to itself — the bike path beaver quickly downed nine trees, causing $4,500 in damage near Riverwalk.

 California Department of Fish and Wildlife officials issued a kill permit after an appeal from city officials — then relented after residents called for a stay of execution.

 Instead, city officials made plans to ship the animal off to Tehachapi, and wrapped 20 Riverwalk tree trunks in orange construction mesh — which, you know, sticks in the teeth.

 ”Isn’t that a sad thing? We get a little rain and the little guy comes out and he gets hit. He was too happy,” said Revelo, who offered to pay to have the animal stuffed and donated to a local museum.

In every possible way Bakersfield has eschewed education on the topic of beavers. They wrapped trees with plastic fencing and now claim the damage of a lone beaver spanned over 15 years. After gunning for him over the course of three presidential terms, Bakersfield believes it was finally run over on the highway. And a generous lawyer has kindly offered to stuff it and put it in a museum.

Mighty white of you, Bakersfield.

Of course WE can look at the calendar and see that it’s February and know that means dispersal month. We know that this was never a single beaver but a family. And some two year old disperser was heading out to seek his own territory and was hit by a car, which apparently surprises people every single time it happens. But we know it happens a lot.

Just think how surprised they’ll be when the ‘ghost’ of the bike path beaver starts chewing those new trees!


Thanks to Robin from Napa who painstakingly filled in the dates on this, we now can see exactly what happened to beaver trapping in California over the last 65 years.

real list

Total Beaver Trapping Take in California (Does not include depredation)

And they wrote back her query with this blow by blow.

  •   Beaver reintroductions occurred from 1923-1949.
  • In 1939, legislation was passed to allow for control of beavers where they interfered with infrastructure.
  • In 1950, the counties within the Sacramento and San Joaquin valley were opened to year-round beaver trapping.
  • In 1955, the California Fish and Game Commission to institute a quota system for the take of beaver in northern counties and on the east side of the Sierra.
  • In 1956, the quotas were lifted from the counties opened in 1955.
  • In 1957, the beaver was classified as a furbearing mammal and provisions for their take when found to be damaging crops or property were instituted (FGC §4180, 4181).
  • In 1958, some Sierra Nevada counties were opened to beaver trapping.
  • In 1959, Inyo, Mono and Siskiyou counties were opened to trapping.

And from 1960 onwards trapping went down and depredation became the drug of choice. Which brings us to where we are today when the vast majority of beaver deaths go uncounted and unreported and we have no idea how many we kill ever year.

And no idea what effect these beavers could have on our salmon and water storage if they were allowed to live.

Back to reality

   Posted by heidi08 On February - 24 - 2015Comments Off

Coming back from the conference one is left with this beaver haze. There are follow-up emails and last minute touches from people who wanted to say something appreciative but couldn’t find time in the moment. There are last minute ideas and connections. There’s a sense that, finally, everyone understands beaver value, and we are living in the golden age of beavers.

And then there you see things like this and come crashing back to earth.

Beaver problems in pond dams

 Oklahoma State University- Not only do they build their own, but beavers can cause significant structural damage to pond dams.  Dam problems can turn into big problems.

 “The typical Oklahoma farm pond dam was built with too narrow of a top and is too steep sided,” said Marley Beem, Oklahoma State Univesrity Cooperative Extension aquaculture specialist. “Such ponds are at high risk of failing when animals burrow into the dam.”

“First, I would recommend calling USDA Wildlife Services to see if they might be able to send out a trapper,” Elmore said. “Beaver are not too difficult to trap if you have a little experience. But, if you miss them in a trap, they are very tough to get, so you need to get them on the first try.”

 If Wildlife Services cannot help, pond owners can take matters into their own hands by trapping or night shooting.

 “I advise shooting, as the only legal trap a private landowner can use is a leg hold trap in a drowning set, which is a little tricky,” he said. “Night shooting works well but you will need to call the county conservation officer and/or sheriff to let them know what you are doing.”

 Using a shotgun is preferred and is much safer when shooting at water. Once the pest has been eradicated, repairs to the pond dam can commence.

Better hurry and get rid of them pesky beaver, you wouldn’t want them sticking around and improving the fish and birds on your property would you? How nice of the University system to offer advice for how to kill them. Higher education at its finest.

Honestly, why does Oklahoma even have a university anyway? They’re clearly aren’t capable of learning new things about beavers.

Marc Murrell: Leave it to ‘Big’ Beaver

Mark Brannock, 51, has been trapping in northeast Kansas since his days growing up in Perry. He admits that trapping for him isn’t necessarily about the money when he sells his furs, but a tie to conservation and simply a way of life passed on from previous generations.

 “My biggest beaver ever was 72 pounds,” said Mark Brannock, 51, an avid furharvester who grew up in Perry. “I caught one this year almost as big and he was 71 pounds.”

 Beavers don’t normally get quite that big.

 “I’d say the average adult beaver weighs between 40 and 55 pounds and those are 3-plus years old,” said Matt Peek, furharvesting program coordinator for the Kansas Department of Wildlife, Parks and Tourism. “One that big into the 70’s isn’t uncommon, but it’s atypical and that’s definitely towards the bigger end of what trappers are likely to run across.

 “Beavers can get to over 100 pounds, but I don’t ever recall ever seeing one that big from Kansas,” Peek added.

There’s no shortage of beavers in the Sunflower State. They’re found in greatest numbers in the eastern part of the state as one might guess — that’s where most of the water is located. Peek admits the beaver population is generally good in those locations based on annual harvest data and damage complaints.

“They’re particularly fond of the same types of trees we are in a lot of cases, especially in suburban areas where people have nice, ornamental trees,” Peek said. “The beavers prefer to cut these down, rather than other undesirable species like cedar or hedge or locust.

 “And maybe the bigger issue is most Kansas beavers don’t build a lodge and they live in bank dens so they can cause some problems with dams (bank erosion, etc.) and then the other problem is flooding and they can back up a lot of water in places in agricultural fields and flood different areas that landowners don’t wish to have flooded,” he added.

 Kansas beavers don’t have a lot of natural predators, other than humans.

 “Coyotes and bobcats will take them if they can get them on land, particularly the younger ones,” Peek said. “Or if a creek goes dry they’re pretty susceptible to predation from those two.”

 Beavers, like many species of wildlife, are fairly short-lived animals.

 “Most of them don’t make it beyond two years, but those that do are capable of living to 10-12 years or more,” Peek said.

Leave it to Kansas and Oklahoma to provide the reality check we need after a beaver conference that seemed to suggest that everyone has learned the things they need to know. Apparently Marc has been killing them so long he has concluded they only live for two years. That is a stunning bit of self-prophecy isn’t it?

Do you know when we were just starting out with beavers, before the beaver subcommittee even formed, the pretend expert who tried to tell our city all about them (Mary Tappel) told the the Gazette that they could breed for FIFTY years. I called the editor in alarm and asked whether that was a typo. He insisted it w as not and called Mary back to verify. At that time Mary was supposed to testify to the subcommittee, and ‘help’ answer our questions,  but after that drama she decided we were too challenge-y and only met privately with city staff to spread her lies.

It all happened such a long time ago I practically forgot until I was talking to someone at the conference about it. Water under the bridge I guess. Anyway a trapper saying they never live longer than two years because I kill them myself is much more accurate. And I for one believe HIS story, don’t you?

Speaking of scientific errors,  there’s a new illustrated book on the subject that Robin sent my way. And the artist chose a wonderful illustration for correlation not being the same as causation that I know you’ll admire. Thanks Robin!

bad argument beaver


Trapping vs Depredation

   Posted by heidi08 On February - 23 - 20152 COMMENTS

Yesterday was a lovely day of post conference glow, but now it is monday and the ominous week awaits us all. There is never enough time to do all the things for beavers that we imagine. Yesterday I poured my free time into puzzling over the trapping records which were meticulously maintained since 1950. I got thinking about it listening to Mike Settell’s presentation about trapping in Idaho.

CaptureYou see, fur-bearer trappers have to report their take of species by county at the end of the season. And Fish and Game has been compiling these records back since 1950. They have to also indicate how many of the furs they sold and for what price. Over the years the very most lucrative fur has been muskrat, with a decade of interest in bobcat as well. Beaver prices have never been worth much, varying in price from a high of 21 in 1980 to a low of 4 in 1970.

If we were to take these beaver trapping records and plot them on a graph they would look like fairly steady slope downwards. There were 1686 beaver reported trapped the year I was born and only 60 last year. Now you might be thinking, wow that’s great! Less beaver killed! But you’d be wrong. Because while trapping has gone down, depredation has gone UP.

It is illegal to sell fur after depredation. And you can imagine that the rugged outdoorsy trapping has gone down as we’ve become more urbanized. Clearly the conflicts with landowners has gone up as we moved into every nook and cranny of wild space.Theoretically the two systems are independent and have different unredeeming qualities For example, there is no limit of ‘take’ on beaver so you could trap all you want. But there is a limit to ‘depredation’ and you can only kill what you have permission to remove.  However, when you trap there is at least some record of how many were killed because you need to report what you took and where it was from, whereas no one has to report their totals in beaver depredation at all. Trapping records, such as they are; are public and online. They are fairly comprehensively organized by county and species. Depredation permits are private, hard to access and cryptically maintained.

In fact, I would argue that depredation is the vast black hole into which our beaver resources are being poured today.They disappear and no one records the loss. Robin and I will be working on a spread sheet of the declining trapping business on beavers, but here is a little taste of the numbers.

CA trapping

You can see the pattern fairly clearly here. The big surprises for me were the numbers taken in specific counties. The year I was born  there were a whopping 96 beaver trapped in Contra Costa County. The 60 year record goes to Plumas county with 282 beaver trapped in 1955. Butte county is a consistent high water mark regardless of year, Stanislaus and Sacramento are high until depredation takes over.

The shocker to me came in the very first record for 1950. when it reports an impossible 182 beavers were trapped in Riverside county in Southern California. The arid region boasts .3 square miles of water. And zero depredation permits in our last accounting. There are minimal numbers of beavers all the years since. So where does this boom come from? I can only conclude it’s a data entry error. Riverside is right next to Plumas in the list, and Plumas often has large numbers. So that’s probably what happened.

Unless there was a beaver invasion in Southern California in the 50′s?