Tuesday 30 November 2010

Guidelines

Guideline - the word has been on my mind for some time. I consulted Wikipedia and found this useful sentence 'By definition, following a guideline is never mandatory (protocol would be a better term for a mandatory procedure).


So what is it with SNH that they should complain that the free beavers of the river Tay in Scotland have not followed the IUCN guidelines? They are, after all, only guidelines, not protocols. 






Now, here is a sight that mystified me. I think that an otter has played around. By the time that I saw this the temperature was rising and the ice was turning to slush.

In the meantime we learn that a 'volunteer' has been appointed to trap the beavers in the Tay. It seems that a particular lodge has been marked for the trapper's attention and SNH's spies have ascertained that it is occupied by one adult and two yearlings. The lodge is said to be near Blairgowrie which, I suppose, means that the lodge is on the river Ericht, a tributary of the Isla, itself a tributary of the Tay.



Here is that same pool a couple of days later.



Here is an email from my excellent friend, Jean-Pierre Choisy, ecologist for the Parc Regional of the Vercors.

Now (XXI° century) in France, in Germany, even in a country with a tremendous human density as the Netherlands are, the Eurasian Beaver is not only accepted but welcome too, for itself and as biodiversity restorer, in spite in some place of problems easy to solve, absolute not to compare with Red Deer or Wild Boar.

Now, Beaver settle again remote places in the Alps, with a human density of some per square kilometer and, as well, the center of towns as Valence, Grenoble, Lyons.

Do I actually understand ?
Scotland would not be able to accept Biodiversity's restoration nor of the Beaver neither by the Beaver ?
I hope not ! I hope I mis understood because of mypoor english
Since tens of years, for me the UK is (was?) the first for commitment for Biodiversity's conservation and restoration in Europe.
But if understood right, I should habe to endure a major and very desillusing change of my perception of the country...

Please, more information and...better I though.

Best regards !

Jean-Pierre Choisy




Thursday 25 November 2010

SNH's Programme for the Welfare of the Free Beavers in the Tay

The word is that SNH/SASA have hired a man to do their trapping and have acquired six traps. This person will concentrate on cleansing the Blairgowrie area to start with. SNH's public relations' person is alleged to have said that the trapping of the beaver was for welfare reasons.


A skin of ice covers the big pond here. Luckily for the ducks the beavers are keeping a passage open so that they can forage for pond weed.


This old birch has come to the attention of the beavers. According to a study quoted in Dietland Müller-Schwarze and Lixing Sun's 'The Beaver - Natural History of a Wetlands Engineer' a beaver in Michigan will harvest 1400kg of woody biomass per hectare per year.




Time for a walk!

Wednesday 24 November 2010

Ethnic Cleansing of the Free Beavers of the Tay?

I took this first photograph yesterday morning during my daily round of feeding our wild boar. At first I thought that this little dam must have been partly burst in the recent heavy rains, but held together well enough for the main part to remain. However, looking at the photographs I took I have come to think that it is one of those cases where beavers have decided to regulate the water level and have done some digging to make this so. 


In this photograph you can see how much the water level has dropped in that section of the burn.

And here you can see that a channel has been dug in the side of the dam by the bank to act as the bypass outlet of the dam.

Now here is some astonishing news

I learned recently that Scottish Natural Heritage had commissioned the Scottish Agricultural Science's Agency to trap and remove the unlicensed beavers in the River Tay. 

What an extraordinary move! It is true that the free beavers in the Tay have no licences from the Scottish Government to be there but, as I understand it, once re-established as a breeding population, they are covered by the protecting legislation of the European Union - the Habitats' Directive of 1992.

People must find it very odd that SNH are supporting a project in Knapdale in Argyll that is projected to cost around £2million of taxpayers, generous charitable bodies' and kindly individuals' money while, at the same time, commissioning the eradication of an accidental restoration that has cost no taxpayers' money.

I should say that I have always supported the SWT/RZSS project in Knapdale - I would support the return of the Eurasian beaver anywhere that was suitable.

How much will SNH spend on their misguided programme in the Tay? I think we should be told. Perhaps there is time for some common sense to intervene and Scottish Natural Heritage will call and end to this folly.




I took this last photograph yesterday afternoon a little after sundown. On the right of the photograph, above the dam, is that fence straining post. Here is a landscape that is both man made and wild.

Have you been watching Prof. Iain Stewart's brilliant series 'The Making of Scotland's Landscape'?
I watched the fourth one yesterday afternoon. You may find it at

http://www.bbc.co.uk/iplayer/episode/b00vz2tq/Making_Scotlands_Landscape_Scotlands_Water/








Monday 15 November 2010

A Washout and Some Work on a Canal

I came across this young dam on the fourth of August and watched its progress over the next three months, but don't seem to have taken any photographs of it until the 9th of November, by which time some heavy rain had washed it about thirty metres downstream from its original site.






That is how it was as a young dam and it grew considerably, but then came the rains of October and I was surprised to find this chunk of dam some way downstream of its original site. Perhaps with more timber struts it would have survived? What will the beavers do now? They may feel that it will be enough to link the dam to the bank where it is now. Will they think it necessary to build a new dam in the original place?





By the time of its washing away the dam had developed extensions on the bank of the ditch and it was just the plug that was pushed downstream




This canal has had some work done on it and, with the recent rains, it is becoming an ever more convincing canal, extending the beavers' penetration of the willow wood.

A snipe flew up as I walked across the wetland just to the left of the picture below. It was the first I had seen for a while. I haven't seen any woodcock around for a while, but frost and some wind from the East  should bring them across the North Sea to spend the winter with us.



Thursday 4 November 2010

Provenance and Some Physics

Now, here is the abstract of a very interesting paper by Duncan Halley on the important subject of what kind of beaver you should get if you are thinking of restoring the species to your country.

onlinelibrary.wiley.com/doi/10.1111/j.1365-2907...x/abstract


In Scotland the official line is to go for beavers from Norway on the grounds that they resemble most the few skulls and bits of jaw that are preserved in the National Museum of Scotland. This seems reasonable enough until you learn that the beavers of Norway lack genetic variety and so could be vulnerable to various problems. It would be worth following the link that I have given to learn more about this.


To my mind the choice of the genetically more diverse beavers from Bavaria makes a lot more sense as candidates for returning to the rivers of Scotland, but there you go.




I had not visited the Wet Wood for about a week, so I thought I should take a walk along there this afternoon. Here is the dam that stops the main ditch and the pond that lies next to it. A little to the left of the dam you can make out the still exposed top of the straining post of a fence. You will find a recent photograph of this post and a shot I took back in 2002.



Here is that straining post as it was this afternoon.




Further into the wood I found that the beavers have been working on the canal. 

My copy of 'Beaversprite' arrived this evening. Reading through President Owen Brown's editorial I found this interesting information. 



'Did you ever wonder how a
beaver can pull a 20-40 pound floating
log through the water? A log that may
weigh more than half the beaver’s
weight? PHYSICS!
Oh my, why did I bring up a
subject most people avoided or hated
in school?. Well, here is the answer.
Weight is the pull of gravity on the
Mass of the log and can be represented
by the equation W = M x g where g is
the acceleration due to gravity and is
9.8 (I will
leave off
the units
to the
chagrin of
all of you
who like
physics).
What this
means is Weight is nearly ten (9.8)
times the Mass, so what the beaver has
to pull through the water is only one
tenth of the Weight. Now the beaver
only has to apply a force of two pounds
(lbs.) for a 20 lb. log and four lbs. for a
40 lb. log. Who would ever think that
physics could be so illuminating!!!'

I have often wondered about the relative cost to the beaver of digging a canal to float timber down it and the cost of dragging branches to a dam or lodge. 

By the way, I have left the quotation in the form it pasted into my post rather than reorganise it.


Here is the web address of Beavers, Wetlands and Wildlife: http://www.beaversww.org

BWW is an excellent organisation, whose purpose is, among other things, to show how people and beavers can live with each other.



Monday 1 November 2010

Golden October


The last few days of October were golden so here are a few photographs to show the Burnieshed burn in full flow after the rains and in this time of sunshine.

The first photograph shows the middle dam below the drive. The beavers are using rhododendron branches to build it up. I have seen this done in past years, but then only a few branches. This year the use of rhododendron is extensive. The footpath is crossed in a couple of places by well used beaver tracks, showing where the animals have been up the bank to cut out branches of rhododendron and birch.





Here we are looking down stream from the middle dam.


This is the famous top dam below the drive, the one below which Ronald Campbell of the Tweed Foundation was photographed in March 2009. Ronald posted the photograph round the web as an example of a dam that salmon would not be able to surmount. This was made all the more interesting when Professor John Thorpe, a renowned scientist in the world of fisheries (and salmon in particular), saw the dam with similar water levels. He told me that he thought that salmon would be able to cross the dam. As it happens, and as followers of this blog will know, this ditch, in the process of rewilding, does not hold salmon at present, though sea trout used to swim up it. I hope that the beavers' revitalising of the habitat will ensure that sea trout will run up the burn once again.



This is the north side of the dam in the previous photograph. The overflow channels are running. The old fence post that stood at the edge of the ditch that was is being submerged by the dam that surrounds it.