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

Month: March 2017


There has been more interest lately in the health of freshwater mammals, and more support for the belief that their decline signals doom for ours. That seems about right to me. And I can think of ONE freshwater mammal in particular that should be carefully protected.beaver phys

Large freshwater species among those most threatened with extinction on the planet

Freshwater megafauna such as river dolphins, crocodilians and sturgeons play vital roles in their respective ecosystems. In a recent scientific publication, researchers of the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin have teamed up with international colleagues to illustrate the factors that currently threaten these large vertebrates. The authors also call for a more comprehensive assessment on these large freshwater animals and for a more targeted conservation plan. Also, a wider range of freshwater species and freshwater ecosystems suffering from biodiversity decrease have the potential to benefit from such megafauna-based actions. Many large aquatic vertebrates, referred to as freshwater megafauna, cover long distances between their breeding and feeding grounds. To ensure their safe passage, they are dependent on free-flowing waters.

The mode of life of the Eurasian beaver and the North American beaver, for example, induces them to shape entire river courses, affecting not only biochemical and hydrological processes, but also in-stream and riparian assemblages; in the Everglades, the American alligator creates and maintains small ponds, providing habitats for a large number of plants and smaller animals. “The importance of freshwater megafauna for biodiversity and humans cannot be overstated,” stressed Fengzhi He together with colleagues from IUCN, the University of Tübingen and Queen Mary University of London, Fengzhi He describes in this publication which factors pose threats to freshwater megafauna. Besides the obstruction and fragmentation of water bodies following dam construction, these factors include overexploitation, environmental pollution, habitat destruction, species invasion and the changes According to the authors, megafauna species are highly susceptible to external factors owing to their long lifespan, large body size, late maturity and low fecundity.

Despite the fact that many megafauna are under great threat, they have been largely neglected in previous research and conservation actions. Fengzhi He and his co-authors call for research focusing on the distribution patterns, life history and population dynamics of megafauna. Freshwaters are among the most endangered ecosystems on the planet, where biodiversity is declining faster than in marine and terrestrial realms. For this reason, it is all the more important to develop sustainable nature conservation strategies forfreshwater ecosystems and their megafauna.

We here at beaver central think Dr. He is absolutely right about this. Our freshwater heroes don’t get enough research. No one knew why our kits died in 2015 and no one knows anything about the population size in general. People like to study smaller species that fit conveniently in tanks in the laboratory. But science has largely forgotten the importance of field research, and how much can be learned just by observing the animals in person.

I don’t share his worry that beavers will be among the first to go. I think they proved their resilience on Mount St. Helen’s and at Chernobyl. Not to mention bouncing back after near extermination once. Beavers are very unusual freshwater fauna because they are NOT the top of the food chain and can travel long distances over land. I am sure they will outlive us.

Especially since we happen to be the greatest threat to their existence, and have been for 1000 years. They might actually be better off.


Yesterday was a very odd 79 degrees in the Sierras in March. Daffodil hill was in full bloom, the mountains were heavy white with snow, and another 17 dead ponderosa pines still need to be taken down at my parents house in the foothills. Because California may have escaped this round of drought roulette, but there are still carcasses all around us and a grim horizon. Not to mention the land drop from the smashed aquifer that Bakersfield is never getting back. Well, enjoy the almond blossoms, and the daffodils while we can.

I came across this looking for footage of the big beaver meeting in 2007. I posted it last year but the video was taken down so rendered un-sharable. With a strike on my Youtube record already from the UK I was afraid to do it. I was delighted to see someone else had. This is cued up for Martinez, but you might want to watch the whole thing. It’s actually pretty good.


Hey! I have an idea! Let’s see what happens when we try to do the work that beavers would do for free if we just stop killing them! Somebody give me a grant!

OSU-Cascades students, scientists make fake beaver dams

BEND, Ore. – By constructing and monitoring artificial beaver dams, scientists and undergraduate students at Oregon State University – Cascades are learning how the health of the surrounding habitat and water can be affected by genuine beaver dams.

CaptureMatt Orr, an assistant professor of biology and Ron Reuter, an associate professor of natural resources at OSU-Cascades are leading the study on the South Fork of the Crooked River in near Paulina, where a team of five undergraduate students installed analog dams and measured soil moisture, steam habitat and water quality.

To construct the dams, the team used small boulders, wood posts and branches from nearby willow and juniper trees, mimicking natural beaver dams. Their initial findings show how the dam of a beaver – the university’s mascot – can positively impact soil moisture and habitat for streamside plants up to 150 meters upstream.

Because beaver have been eliminated from many lands throughout the West, particularly lands that have been impacted by grazing and agriculture, the research team’s work intends to provide a low-cost, low-impact approach to restoring stream and streamside habitat.  By trapping sediment, beaver dam analogs also help to raise the streambed, which reconnects downcut streams to their former floodplains, increases “green space,” and reduces the destructive force of high flows.

This spring and summer, the research team will expand the monitoring to measure sediment, riparian plant health and fish passage. The project was funded by an OSU Grand Team Challenge Grant, the Bella Vista Foundation and private donors.

Good idea! Next let’s see if the students can reduce the fly population by making spider webs too! I mean if we’re taking over natural functions, why stop with the beaver? Since you aren’t teaching students to be ADVOCATES for the beavers to stop them from being trapped on farmland.  Maybe while you’re at it, lets see you can raise the bird population by making little nests so they have more time to spend on a second clutch every season?

Honestly. They obviously just fund any ol’ programs now.


Yesterday a reporter for the East Bay times came by to talk about a 10 year retrospective on the beavers. It was an odd interview I think maybe because he wasn’t feeling well, and it was early, and it was in my house. He had strange ideas about the beavers I thought, like saying they were “more popular now then when they had been saved in 2007”. I told him I thought their local profile 10 years ago had been HUGE before, and that’s why they were saved. In contrast people hardly think about them now, unless they’re on the news.

After we talked for an hour the photographer arrived and wanted to film me saying the same things for another hour. Which was tiring but less odd, because she wasn’t feeling sick. But she told me to be ‘pithy’ once which alarmed me because I usually am already. I’m saying this because I hope I said the right things, in the right way, and we don’t get a ridiculous beaver article this weekend.


Anyway, happy ending alert, after it was all over I got an email from Sean Dexter of Condor Consulting on Green Street because he had snapped a photo with his phone that he thought I might like to see.

condor consulting
Beaver at Ward Street: Sean Dexter

He took this on Wednesday of last week, which means their was a sighting Sunday evening, Wednesday evening and Thursday morning. That’s enough days in my book to say that we should all be looking for them to show up again. We’re heading to the Sierras this afternoon for a few days but you can be bet will be there keeping watch the moment we get back!


Parry Sound is in Ontario Canada directly north of New York. It is famous for having the deepest freshwater seaport in the world and various hockey achievements. This morning it has decided to offer a pleasingly accurate beaver article with some very nice photos. Enjoy!

The industrious beaver is not afraid of hard work during the winter

PARRY SOUND SIDEROADS AND SHORELINES — Winter is the time of year when many wild animals living in the Parry Sound area have adapted to escape and wait out the heavy snowfalls and dropping temperatures. Bears hibernate in cosy dens, squirrels have built nests and stashed food away, and frogs have dug into the lake bottoms and drastically reduced their temperature. But the industrious beaver continues to be quite active during winter until the lakes freeze over completely, and even then this animal can be seen busily repairing any damage to its lodge or dam.

Beavers are completely adapted to an aquatic existence and look quite awkward when slowly waddling on land where they are vulnerable to coyotes and other predators. Their front paws contain claws that can easily manipulate twigs to chew the inner bark of branches – their primary food source. In the Parry Sound area, their favourite wood is the aspen tree but they will also eat ferns, mosses, dandelions, dogwood, and aquatic plants, to name a few. 

The resulting dam sets in motion an entire alteration to the ecosystem. Hence, beavers are considered a “keystone species” (one that plays a unique and crucial role in the way an ecosystem functions. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether). The building of dams modifies and creates a dramatic change to the surrounding environment. The backwater flooding from the dam floods the lowland near the creek; trees die creating an opening in the forest canopy; aquatic plants and shrubs soon develop, making a favourable habitat for waterfowl, herons, moose, amphibians, fish, insects, muskrats, otters and a score of bird species. Their activity purifies water and prevents large-scale flooding.

Over a period of time the food source runs out and the beavers move on; the dam breaks and eventually a meadow forms, creating habitat for an entirely new group of species. And thus, the vital chain of evolution around a beaver pond continues.

A few years ago, the television program The Nature of Things featured a show entitled “The Beaver Whisperer” outlining the efforts of a few Canadians who have studied and/or worked with beavers, giving an in-depth account of the beaver.  The Parry Sound area is home to many beavers and if you are lucky enough to see one around twilight, watch and observe the complex behaviour of this fascinating animal. 

Nice to read that Jari Osborne’s great documentary is still making an impact! (Although it was called the Beaver Whisperers as in more than ONE). And nice to see even a brief discussion of beaver benefits from that neck of the woods.  They need all the allies they can get. I’m going to assume, that even though they’re very clever, the beaver in that photo isn’t balancing a aspen log on its back. I’m pretty sure the log is just laying in exactly the right place on the ground behind him. Although that would be quite a feat if it were possible. Think about it, how would the beaver even get the log there in the first place?

I think it’s one of those photo placement victories, like someone photographed pushing the tower of pizzaa over, or a baby holding up the moon. But it had me confused for a while, I admit. Thanks for the mystery!


Good news on Sundays is an easy policy to follow. Especially when Napa wins the Wetland War once again. Credit Rusty Cohn for bravely visiting Friday afternoon Tulocay creek where the beavers are very slowly rebuilding their damaged dam. Guess what he saw?

Napa wins again
Woodduck in Tulocay Creek by Rusty Cohn

Ahhh this inspires a confession. There are three half-truths I regularly tell about our beavers in Alhambra Creek. The first is that the folks at the meeting all spoke up for beavers. That’s not entirely true, because there were at least 5 ‘nays’ out of the 50 pro-beaver speakers in attendance that night. They were deliberately positioned at the beginning and end of public comment for maximum effect. And they were the definite minority. But they were there.

The second is that Alhambra Creek hadn’t seen mink in 25 years. I actually don’t have a source for that except I surely hadn’t seen it before.  And I’ve lived downtown as an adult for 25 years. And it sounds about right. Although I’ve been saying it for a decade so that’s more like 35 years. Which puts us somewhere in the eighties was wasn’t really known for the greatest creek restoration. But, it conveys the idea that we saw different things when the beavers came. So I had retained it in the canon.

And the third almost-lie I repeat, was told to me by ward 7 manager for East Bay Regional Parks. He has since died but Ted Radke was a big beaver supporter and avid duck hunter – and he told me early on that after the beavers came we saw WOOD DUCK for the first time.

He said it to me at the celebration for the 75 anniversary of EBRP, and he insisted it was true. But I never saw one, before or since, and shortly after he said it hooded mergansers were seen for the first time in their full colors. And they’re striking ducks, so one can easily imagine he got them confused. But it’s a good story because wood duck is the ‘crowning glory of ducks’ and intimately tied to beaver ponds. So I’m inclined to repeat his story as if it were true.

But never mind, because once again NAPATOPIA has beaten us to the punch.

Great photo Rusty, Jon and I both laughed aloud when we saw it. Because we never doubted you’d be first!


Yesterday three bright and beautiful copies of MIT professor Penny Chisholm’s book on the water cycle arrived for the silent auction. She included a note thanking us for saving beavers! They are so brilliantly colored and so well told that they’re sure to be a hit with the parents and children there.  Your very smart grandchildren might deserve a copy now, so go here to get your own. Thank you SO much for your help Dr. Chisholm.

closeNext came a present all the way from Rhode Island, where artist Carrie Wagner of Sepialepus donated a truly breathtaking and whimsical map of our golden state. I had originally seen her map of New York which included beavers, and asked her to think about donating. When she enthusiastically agreed she told me that she used to live in San Francisco and knew just where to add the beavers to her California map. Then she sent this, which is large, beautifully detailed and glorious. I’m including a closeup of the beavers so you can appreciate them fully.

CAMAP

Thank you SO much Carrie for this wonderful donation! I can’t wait to see how folks appreciate this at the festival!

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