Archive for the ‘Beavers and climate change’ Category

To Beaver or Not To Beaver?

Posted by heidi08 On May - 25 - 2017ADD COMMENTS

More silly mulling from the Scottish countyside: Should beavers be allowed or not? A reader on the Tayside group pointed out that this same argument could have been made 15 years ago, I say probably longer than that.

Beaver reintroduction – what’s the story?

Their reputation as strong swimmers and prodigious engineers is not an understatement. Their large incisors and clawed front feet enable them to construct dams and lodges that can extend for hundreds of metres, as well as burrows of up to 20 metres into the riverbank.

“Any species introduction, particularly if it has not been in this country for hundreds of years, can have a massive impact on the many benefits that the countryside delivers,” Mark Pope, an arable farmer from Somerset who has instigated numerous initiatives to provide habitat and food for birds and insects and encourage diverse plant species on his farm, said.

“In the case of beavers, the NFU has concerns about the damage to farmland and the landscape caused by their physical activities.” Mark, who is also chair of the NFU Environment Forum, added. “Farmers and the public must have the tools to manage the impacts beavers will have to farmland, the countryside, flood defences and urban areas.

“Beavers can add biodiversity, as well as the interest, enjoyment and socio-economic benefits they can provide to many people. What the NFU is very clear on is that in some locations there is a clear need to manage this species to minimise undesirable impacts on agriculture, forestry, inland waters and other land uses.”

There is increasing interest in the beneficial role beavers could bring to habitats. The natural activities of beavers could help to regulate flooding and improve water quality, if managed properly. The Devon trial on the River Otter, led by the Devon Wildlife Trust in partnership with Clinton Devon Estates, the University of Exeter and the Derek Gow Partnership, has been exploring the role of beavers in managing and creating wetland habitats, the impacts on water quality, and influence on water flow and flood risk.

Tolkein once wrote “Go not to the elves for council, for they will say both ‘No’ and ‘Yes’.” Mostly no, though.

On the other hand, beaver burrows near watercourses can weaken river embankments and flood defences. Material felled and gathered by beavers for dams and lodges can create flood risk downstream and block drains upstream. The potential consequences of this for farmland and the rural economy is a cause for concern.

It is estimated that the costs of the 2007 and 2013-14 floods on agricultural businesses alone were £50m and £19m respectively, not to mention the wider economic impacts on local employment, infrastructure and utilities and the damage caused to people’s homes and communities.

The knock-on effects can be wide-ranging. The loss of productive farmland, for instance, would have a detrimental effect on food production and supply.

The Scottish Beaver Trial was a five-year project between the Royal Zoological Society of Scotland, the Scottish Wildlife Trust and Forestry Commission Scotland to undertake a trial reintroduction of beavers to Knapdale, Mid-Argyll. The trial concluded in 2014 and as a result the Scottish government is considering recognising the European beaver as a native species.

A change in the legal status of beavers raises additional concerns. This is because beavers have no natural predators in the UK so it is important that populations can be managed, particularly if they are present in extensive low-lying areas such as East Anglia, Wiltshire and the Somerset Levels where their activities could block field drains leading to waterlogging (known as ‘wetting up’) of productive farmland.

Clarification: Beavers might benefit us if they don’t kills us all first.  “We killed off all their natural predators in the UK so there’s nothing left  to kill them and their numbers will swell like taxes with national health”. Are there no otters? No bacteria? No vehicles in your land? Beavers just don’t get killed by predators you know. And honestly, why act like you want to explore an issue and ONLY speak to one farming fiend from the National Farmers Union?

Who’s going to list all the many benefits for fish, wildlife, birds and water storage that come with beavers? Who’s going to talk about how much you can learn about nature by watching them? Who’s going to say how much they improve the health and vitality of urban waterways?

We need a National Beavers Union!!!



Beaver Reverberations

Posted by heidi08 On May - 19 - 20172 COMMENTS

Yesterday’s blockbuster report is sounding bells all over the northern hemisphere. (Probably everywhere but Wisconsin.) The latest accolades come from Canada, where the CBC wants every countryman to know that beavers are Worth A Dam.

Beavers are dam important for the ecosystem

The beaver is a Canadian icon. To some it’s also a royal pest.  Beavers are more than just a nuisance, though. They are also important engineers of our environment.  A new study published in the journal PLOS One has discovered just how important beavers are in protecting habitat.

What role do beaver ponds play in the ecosystem?

beaver-kachur-2There are lots of species that rely on beavers to engineer the environment to suit their own needs. Creatures like the Sandhill crane, the mule deer, and, most importantly, juvenile fish. Not only that, when there is a beaver pond, the water is able to be better absorbed by the land, allowing it to resist both droughts and floods a lot better. 

For a long time, it was believed that beaver ponds increased the temperature of water in the ecosystem due to its greater surface area absorbing more energy from the sun. That was always thought as a possible way that beaver ponds could be damaging the surrounding ecosystem.

This assumption has been overturned by new research. Nick Weber is with Eco-Logical and his team conducted experiments along Bridge Creek, Oregon.

“As the volume of surface water increases,” he says, “it just takes a lot longer for streams to heat up during hot summer days.”

The work was done in the high desert of Oregon where temperatures can soar in the summer. But it’s not much different from what we can get in Canada, especially as our world warms.

Why is this significant?

It’s significant because the high temperatures of river water — which on some days can reach up to 29 C — is problematic for fish like salmon and trout. These fish need temperatures closer to 25 C, which is exactly what is achieved by having a beaver pond. Having much cooler water increases the survival of juvenile fish like the steelhead trout. 

Needless to say, when we are living in the current warming world, it’s important to find ways to reduce the impact of higher global and water temperatures on important stocks like salmon.

So the proposal is to take inspiration from nature, and the beaver, to help restore habitat by constructing artificial beaver dams.  And the coolest part is that beavers eventually take over the dams after a few years.

Not only can the dams restore river systems, but it means beavers might be guided into building dams where they might reduce the impact on people’s lands.

Hurray for beavers! Everybody worships at the ‘salmon and trout’ alter, it seems.  Birds and frogs don’t matter as much. But that’s fine. Whatever reason you find to appreciate beavers is good by me. It’s wonderful how surprised folks are by this news, which is old news to us. I think Pollock was talking about the cooling effects of hypoheic exchange 10 years ago, but better late than never.

All this excitement has clearly made the researchers giddy, because yesterday Dr. Wheaton forwarded me an email from the senior author, Nick Weber, excitedly showing photographic evidence of beavers using the BDA’s they had made. Look closely at the picture,  because I see something other than beavers. I especially like that patient coyote.

Do you think Joe Wheaton is trolling me?


Come on in, the water’s fine!

Posted by heidi08 On May - 18 - 2017Comments Off on Come on in, the water’s fine!

beaver physAnother block buster from our friends at the science site that should be called “Beaver”. This morning the news has also been picked up by plenty of followers including “New Scientist”.  Because beavers are just rock stars like that, you know?

Beaver dams may buffer against temperatures that threaten sensitive species

Both natural and artificial beaver dams may alter stream temperatures which may benefit temperature-sensitive salmonid species, according to a study published May 10, 2017 in the open-access journal PLOS ONE by Nicholas Weber from Eco-Logical Research, Inc., USA, and colleagues.
Beavers are ecosystem engineers, altering stream temperatures by building dams that increase surface water storage and connectivity with groundwater. Some studies suggest that the dams make water warmer and so are detrimental to salmonids, which are sensitive to . Weber and colleagues tracked beaver dams and monitored water temperatures along 34 kilometers of the John Day River in Oregon over eight years. In addition, the team assessed the impact of artificial beaver dams on water temperature along four reaches of Bridge Creek.

Yes beaver dams lower the temperature for sweaty fish. We here at beaver central have been touting this fact for years. Pollock proved it years ago, but now it’s especially even more extra proven. Has any creek been the subject of more study than Bridge Creek? I doubt it.

The researchers found that beaver dams may alter stream temperatures to the benefit of salmonids. Studies suggest that juvenile steelhead salmonids in Bridge Creek experience extreme stress at about 25°C, and the researchers found that maximum daily temperatures in much of the study stream exceed this temperature for much of the summer. However, temperatures rarely exceeded 25°C after the proliferation of beaver dams, likely because they help moderate temperatures both by increasing water storage and encouraging exchange between surface water and groundwater exchange. This fits with the fact that both beavers and salmonids were once more abundant and widely distributed in North America, and suggests that beaver dams could help mitigate the thermal degradation that can threaten sensitive species.

Dr. Weber notes: “Beaver are often considered a keystone species, and their propensity to build dams plays an integral role in maintaining biodiversity and enhancing aquatic processes that benefit an array of aquatic and terrestrial organisms. Recognizing this, beaver relocation efforts and installation of structures designed to mimic the form and function of beaver dams are increasingly being used as effective and cost-efficient approaches for restoration of stream and riparian function. Despite this trend, the notion that beaver dams negatively impact stream habitat remains common, specifically the assumption that beaver dams increase summer stream temperatures to the detriment of cold-water species such as trout and salmon. However, by tracking beaver dam distributions and throughout a high-desert, scientists have demonstrated that beaver dam can actually reduce high stream temperatures by increasing surface water storage and connectivity with cool groundwater. These results suggest that construction of artificial beaver dams and beaver relocation projects could be used to mitigate the impact of human induced thermal degradation that may threaten sensitive cold- species.”

If you need the reference to go look up it’s here. Feel free to notice how many of the names are friends of this website.

Weber N, Bouwes N, Pollock MM, Volk C, Wheaton JM, Wathen G, et al. (2017) Alteration of stream temperature by natural and artificial beaver dams. PLoS ONE 12(5): e0176313.

Dr. Wheaton wrote yesterday to make sure I saw it, but three beaver readers had beat him to it. Let’s hope all those backwards thinkers in Wisconsin who rip out beaver dams to protect their baby trout read it and at least think, huh??? Maybe they’ll even start to read the research later than the 1970 study they tuck under their pillows at night.

Our Edinburgh professor friend saw this photo last night uploaded on to the California Academy of Sciences page “biographic”  and sent it our way. I knew you’d appreciate it. No sissy GoPro camera for this lovely shot. Read about the sturdy and patient French photographer who got this beautiful shot.
Castor d'Europe; Castor fiber; transporte une branche sous l'eau; BBC 2011

Louis-Marie Preau has been watching beavers in the Loire region of western France for more than 15 years. He’s never forgotten the first time he saw an adult delivering a tasty branch to its family underwater—but it took him four years to successfully capture this intimate scene. Each evening, wearing snorkeling gear and weights, he would lie motionless on the riverbed for two to three hours. Finally, one evening, his patience paid off. Preau had only just plunged into the water and positioned himself when this adult returned with a freshly harvested poplar branch to feed to its three young kits. He was impressed by the beaver’s strength and determination, as it dragged this leafy meal through the water. Saumur, France