Sociable

Monday, 29 June 2009

Beavers and Bumblebees

Tony Morgan is one of the inhabitants of Bamff. In fact he and Barbara live in the ground floor flat. Morgan is a man of high standards and regrets that the verges of the drive are not mown.

'All those weeds!' he exclaims, determined to wind me up.

In this, Tony shows that, along with so many people, he has a tidiness aesthetic that is often unfriendly to biodiversity.















On the other hand, I am delighted with the abundant growth of plants and what this means for other wildlife, whether it is the hedgehog that scuttled into the undergrowth as we drove by on our return from a party one night, or the bees and hoverflies that buzz to and fro in search of pollen and nectar.

I noticed this spider on some ground elder (Aegopodium podagraria) this afternoon, while trying out a borrowed macro lens on my camera. The spider sat discreetly in the middle of a very fine web. It would be great to know its identity.






And this brilliant fly. There is the metallic green one that lays its eggs in wounds in animals, but I think this one is different.














Bernd Heinrich's 'Bumblebee Economics' was first published in 1979 and republished with a new preface in 2004. It is a classic work.

The first chapter starts with a description of bogs and their association with bumblebees and beavers. He writes from the perspective of someone who lives in Maine, where beaver bogs are relatively rare bits of open ground in a country where heavy shade is cast by the forest. Flowering plants can flourish in the swamps created by beavers.


In that respect this country is very different and yet there is a similarity in that diversity of flora is denied to invertebrates by the practices of modern agriculture and forestry. The recovery of wetland is, therefore, vital to the continued existence of many life forms.


























Tuesday, 23 June 2009

Some Views of Strathmore near Meigle





Yesterday, Monday 22nd June, I visited the Dean Water. I thought I would publish some photographs to show the kind of landscapes that predominate in this part of Strathmore.



Here we are looking North-East. A field of barley is in the foreground. The line of trees marks the bank of the Dean Water. Beyond is more barley. The hills in the distance are the foothills of the eastern Highlands.

The geology of this country is mainly Old Red Sandstone: the soils derived from these rocks, which were laid down as deposits in times when a desert climate prevailed, are among the most fertile in Scotland.




Strath Plastic is manifest in the great polytunnel on the left of the photograph. It is full of strawberry plants, waiting for Czech students along with Poles and Slovaks (and some others) to come and pick them. This track leads to the Dean Water and a rickety old bridge that crosses it. Running along this track is a sunken gas pipeline.








In the right foreground a pump sucks water from the Dean and conveys it to the polytunnels to feed the strawberries. A fine rain sprays out of a leak in the pipe. The A94 road from Perth to Forfar runs behind the hedge in the distance.








And here, amidst all this agribusiness, runs the Dean Water with its all too narrow riparian edge.












The trapper still has his apples on their sticks. As you see, one has been nibbled by something, perhaps insects? Would it not be wonderful if the co-existence of beavers and intensive agriculture could be demonstrated in this river, rather than hoping to trap and remove any beavers found living here?

Monday, 22 June 2009

Clarifications

I realise that I was not clear in my description of Roger Wheater's comparison of the financial importance of salmon fishing to the potential importance of beavers to the Scottish economy. The claim is that salmon fishing in Scotland as a whole is worth £112 million and that the potential value for tourism of the returned beaver to the economy might be £2 million.

Derek Gow has pointed out to me that the value of the return of the sea eagle to Mull is reckoned to be £1.8 million annually at the present time so it is likely that this is an underestimate.

All the same Roger's comparison is absurd, it seems to me, because it compares an established 'industry' with something that is largely hypothetical.

Why make this comparison at all unless you think that beavers are somehow going to destroy, or seriously affect the salmon fisheries, which is the Tweed Foundation's line.

In its campaign to prevent or promote antagonism to the trial release of beavers in Argyll, the Tweed Foundation has given publicity to the report (http://atlanticsalmonfederation.org/pei/2009peireport.html) from Prince Edward Island in Canada that attributes decline in catches of salmon to the presence of beaver dams.

Daryl Guignion, who wrote the report for the Prince Edward Island Atlantic Salmon Foundation stated only a few months before this was published in March this year that 'the biggest threats to salmon on P.E.I. are sediment and runoff coming from farmers fields and highways, and rivers blocked by bridges and culverts that prevent salmon from moving upstream.' (CBC news 11 August 08).

A Google search (CBC news Daryl Guignion salmon as key words) suggests that there is a long history of problems with the rivers of Prince Edward Island. These have much to do with misuse of the land as mentioned by Professor Guignion and rather little to do with beavers.

Sunday, 21 June 2009

A Beetle and an Exhibition

I thought I had published this post, but here it is.

Owing to the speed of the current, I took only one photograph on my recent paddle down the Tummel to just short of its confluence with the River Tay. Here it is: this iridescent beetle landed on the lid of my water tight barrel. Who can tell me what it is?














The next photograph comes from a publication that Perth and Kinross Council put out to promote all the possibilities of this part of the world during the summer. Among many things, the Perth Museum is holding an exhibition entitled 'Return of the Natives'. I am delighted to see that they number beavers among successful returns that include sea eagles, polecats and several others.

Saturday, 20 June 2009

A Jaunt down the River Tummel

Yesterday, 19th June, I drove in my Toyota truck to feed the wildboar. As I drew up at the feeding place I found two beautiful young women with their babies. What joy! They were out for a walk, they told me, and like to come to Bamff, where they may see the boar and admire the beaver dams. Nicky and Wendy, for such were their names, told me that they had come to live in Alyth (the nearby town of 2,500 inhabitants) because of the nearness of the hills. A few moments later Eliot, Nicky's husband, arrived on his bicycle.

All this reminded me of the comparison that Roger Wheater had made in that interview with the programme makers of Scottish Television. The salmon fishing industry is worth £112 million and tourism is worth £2 million, he claimed, but mentioned nothing about the value of recreational access to the country for those who live there. I think that John Muir, William Cobbett and many others would have had something to say about that. Nor, so far as I remember, did Roger have anything to say about the wider ecosystem services that wetlands, and through them beavers, provide.


Wheater appeared to think that experience of salmon and beaver interactions from other countries was irrelevant, that Scotland was unique despite Duncan Halley's evidence from Norway.


Here is a map of the catchment of the River Namsen in Norway.








Where is this? Some river scene in Scotland, perhaps?







No, this is the River Namsen at Overhalla.












Or this? Somewhere around the River Spey?





Another photo of the Namsen at Overhalla.











The odd thing is that salmon were undoubtedly far more abundant in the time when beavers lived and swam in our rivers. It is the human intervention that has been and is the problem - massive drainage for agriculture, canalisation of river systems, pollution (whether point or diffuse).

I liked Helen Phillips article in 'The Guardian' of 19th June

http://www.guardian.co.uk/commentisfree/2009/jun/18/climate-change-wildlife-environment

Encouraged by Eliot, the cyclist's, suggestion that I should take a bicycle and leave it at the intended end of my canoe journey, I drove to Pitlochry that afternoon, leaving my bicycle at Haughs of Tulliemet.

I launched my canoe in the River Tummel below Pitlochry theatre and almost paddled into two anglers on the opposite bank in my attempt to avoid fast approaching rocks (I exaggerate, but you might think that I had from the consternation of their gaze). The river was flowing at about five mph according to my GPS and so I had to concentrate on avoiding rocks a good deal, which meant that there was little time to spend in looking for any signs of the presence of beavers (of which I saw none).

I passed several more fishers, all friendly, and flailing away industriously at the river. I saw one osprey, many goosanders, some with families of ducklings. There were sandpipers, oystercatchers, and the ubiquitous mallards.

My landing place was unremarkable for its mown grass and the neat fishing hut. It is amazing to me how salmon fishers like to convert the river banks to suburban neatness, complete sometimes with flowers in pots by the huts.


Thursday, 18 June 2009

A Ragbag

I took this photograph of a pinky red fungus on a spar that is part of one of the dams. Can anyone tell me what this fungus may be?












On Monday evening Roger Wheater came to take part in the shooting of a series of programmes about salmon for the Gaelic service of Scottish Television. The series is to be called 'Turas a'Bhratain' (the Salmon's Journey). Roger worked in the national parks in Uganda for fifteen years (or twenty, I can't remember which), was director of the Royal Zoological Society of Scotland and, on retirement, became Chairman of the National Trust for Scotland. Since handing on the chairmanship to Seonag Macpherson, Roger has become a director of the Tweed Foundation (Yes! the Zero Tolerance for beavers Tweed Foundation) and has recently taken on the chairmanship of a committee that is to look into the interactions of beaver and salmon during the time of the trial reintroduction in Knapdale.

Unfortunately, I did not have the wit to take any photographs of the process of filming and talking. Roger arrived somewhat early at my invitation so that we could take a quick walk about.

In due course the STV people arrived and we started on the business of filming. All this went off well enough with the customary repeats ('That was great - can you go back to where you were and start over again?') Then came the section where Roger was to be interviewed. This took the form of some questions, to which he replied. And then it was my turn to answer some questions, but quite different ones. This was very frustrating because there was no opportunity to answer, or offer views on some of the things that Roger Wheater had said. He had been very insistent that the current official trial in Knapdale was only a trial and that there was still a need to do research to see if beavers and salmon could co-exist in Scotland. Roger told the interviewer that he was completely neutral on the subject of whether the beaver should return to Scotland or not. Considering that he was a member of the board of Scottish Natural Heritage around ten years ago, when they took the decision to reintroduce the beaver to Scotland, I found all this rather surprising.




The renewed activity of beavers in their original enclosure encouraged me to put out a couple of Trail Cameras. I rather liked this clip, though unfortunately there is no sign of a beaver in it. I shall have to concentrate on the art of trail photography - too often I am disappointed with results.

The beavers don't like the pink light that the camera emits and I don't like to bait the area because I don't want to get the animals used to apples: any suggestions?
video



Saturday, 13 June 2009

Dams, Salmon and the Tweed Foundation


This is a photograph of one of the dams here at Bamff, taken on the 12th of March this year by Bob Laughton, biologist of the Spey Fisheries' Board. The person standing in the water below the dam is Ronald Campbell of the Tweed Foundation. I am the figure standing on the bank. I copied this photo from the website of the Tweed Foundation


The Tweed Foundation's web site is well worth a visit, not least the section entitled 'Fish & Beaver - The Facts'. It should be borne in mind that when the Tweed Foundation mention the word 'fish' that means salmon primarily. Trout may be included and they have extended their interest in fish to include grayling, but other species of fish are tolerated at best, or like anything else in the biota that may 'interact' with salmonids, be subject to persecution. As to the proud boast that you will get a definitive statement as to the 'facts' of the interactions between salmon and beaver, I fear that the impartial reader will be intrigued but disappointed.)

Dr. Campbell has been using this photograph as an illustration to support his case that salmon will not be able to pass such dams and that this will be catastrophic for the fishing of salmon in rivers like the Tweed and its tributaries.

This is an odd assertion because the Tweed and its larger tributaries are unlikely subjects for blocking by beavers, being wide and fast flowing. Eventually a recolonisation of the Tweed by beavers would reach the smaller tributaries, but would they want to be there, considering the dearth of riparian woodland? Probably not.




The next photograph, taken on the 4th of March when the water level was much the same as it was on the day of Ronald Campbell's visit, shows the overflow that the beavers left as a chute. When John Thorpe, the distinguished president of the Fisheries' Society of the British Isles, came to visit Bamff on the 5th April, when the water level was once again much the same as it had been at the time of Ronald's visit, he thought that salmon would be able to pass up the overflow and into the pond beyond.




On the other side of the dam is another overflow with a small waterfall and thus the potential to become a passage for fish. This photograph was taken on 16th February this year.









Professor Thorpe also took a radically different view of the interactions of beaver with salmon from that of the Tweed Foundation. Essentially, if I have remembered him rightly, he thought that the enormously enhanced productivity that the activities of beavers conferred on a river system could only improve the prospects for salmon.

The work of Sigourney et al. is a contribution to this point of view (see 'Transactions of the American Fisheries Society' 135:1068–1075, 2006).


I should say that Professor Thorpe and Dr. Campbell were in agreement that the lowest dam of the flight of three would be impassable to migratory salmon in its current state. It will be interesting to see how this dam evolves and changes because if one thing is certain about beavers and their activities it is that they are highly dynamic.





Essentially the Tweed Foundation is about maximising production of salmon, whereas the ecological approach to rivers, of which Professors John Thorpe and Robert Naiman are proponents, is about the whole riparian ecotone. The Tweed Foundation are condemned by their charter (or whatever document describes their purpose) to a narrow view of the freshwater world. Like the forester who cannot see the wood for the timber in the trees, the salmon managers in this instance are unable to see the river for the fish. (Though I should say that Ronald Campbell and his team have done excellent work in the Tweed and its tributaries over the years in removing manmade obstructions and in carrying out important work in the restoration of riparian woodland).

When thinking about beavers, their dams and the landscape, it is important to remember that the topography determines how the dam will be built. At Bamff the dams I have photographed for this blog are built across an agricultural drainage ditch. This ditch was first dug probably in the late eighteenth century. Since then it has been 'cleaned' out periodically and the profile of the ditch has become deeper and more wedge shaped through time.



Before the arrival of the beavers the ditch was about thirty centimetres wide. This photograph looks east from the place where the previous one was taken.

















Since the beavers created their ponds these have become alive with trout. This is the pond upstream of the dam that would be uncrossable at present.











Therefore the beavers, in wishing to block the ditch, started by damming the wedge. This, eventually, is what salmon would have difficulty in jumping if such a dam were in a salmon river. Although salmon can leap up to about two metres in height, they need a deep enough plunge pool below the dam, and a nice standing wave there from the water coming over the top of the dam, to carry out their leap successfully.

Having built the wedge and blocked the water course (in fact, the dam is really a filter and not a complete blocker of the water that lies upstream), the beavers' next step was to extend its length in order to capture, or direct, the water that flowed round the dam as the level of the water upstream was raised. Thus beavers began to restore a braided character to what at Bamff, for example, has been a simplified drainage system.

To be fair to Ronald Campbell and the Tweed Foundation, they are worried about the capacity of salmon to pass beaver dams in a small tributary in a dry autumn. Given such a problem I don't see why they shouldn't be allowed to cut notches in dams to allow salmon through, as is done in the Miramichi River in New Brunswick, Canada. Although it may be worth pointing out that if the drought is so great, the pools created by the beavers' dams may well be preserving such young fish as are living in that part of the river system.

The photograph below was taken by Duncan Halley on the 5th May 2008. It shows a dam on the Leirbekken in Norway. The dam itself is submerged by the flood waters and the force of the water flowing over the dam has produced a fine standing wave to propel any migrating salmon over it.




















Tuesday, 9 June 2009

Some Thoughts on that Paddle down the Dean









The pungent fragrance of liquorice greeted my nostrils as we carried my canoe and equipment down to the banks of the Dean last Friday.

I set off as I described in a recent post and contemplated the sides of the stream. In many places, especially on bends, riparian owners have dumped loads of rock into the river in order to limit erosion, especially in time of flood. This creates an unpleasant hazard for canoeists in that these boulders are sharp and some of them roll into the middle of the stream, where they lie in wait.


When I bought my kevlar canoe a friend told me that I would cry the first time it was scratched, but that thereafter I would become inured. So far my worst accidents have been an unwise attempt to paddle over the weir at Ruthven in low water and striking an iron bar when coming into Bridge of Crathies, near Meigle. Both accidents required repairs, using patches of kevlar, bought at Brookside Canoes' store at Inveralmond in Perth.

Many of the place names in Strathmore ( Great Valley) refer to the former wetness of the landscape. Meigle comes from an old British/Pictish word for 'bogginess' and you canoe through the surviving bit of that bog as you head down the last stretch of the Dean from Cardean to Bridge of Crathies. The date in the photograph is carved into the east side of the bridge.

The surrounding landscape is one of intense agriculture. The big farms with their modern sheds and equipment mostly have great stacks of potato boxes, built high. Huge polytunnels cover large areas of the country to the extent that some wags refer to Strathmore as Strathplastic.


Some crops need to be irrigated, so from time to time the canoeist sees pipes emerging from the water to disappear up and over the high bank. The drumming of pumps can be heard, showering water onto the thirsty crops.

What were the apples doing then, impaled on their willow wands? It seems that the Royal Zoological Society of Scotland have been asked by the Scottish Agricultural Science Agency (SASA) to trap beavers in the Dean Water and perhaps elsewhere in the catchment of the Tay, from where there have been reports of the presence of the animals.

The beaver that made landfall in the Tentsmuir Forest in Fife has now been caught. I think that it must have been washed out by the tide and managed to swim ashore. Where is that poor beaver now? Perhaps it is on its way to England, where there are moves to bring back the beaver?

The beavers concerned must all be escapes from places where they have been enclosed, which means that they are all Eurasian beavers. Such was the case with the beaver that was captured at the Sandyknowes Fishery near Bridge of Earn in 2007. It seems, however, that some 'authorities' think that a gang is releasing beavers into the wild and that these beavers may be North American and thus exotics, which must be caught. This seems to me very unlikely.

Who was it who thought that with the decline of terrorism à la mode de George W Bush eco-activists would become a subject for the attention of the security services? Runways, coal fired power stations, beavers? Aaaaargh!

A beaver in the Big Pond at Bamff eats some sedge on a rainy evening in June, unaware of the wickedness in the world around.

Monday, 8 June 2009

Return to the Wet Wood




Tony Morgan told me about ten days ago that he thought he had seen signs of renewed activity in the beavers' original enclosure. So, this afternoon, having forgotten what the various things that I had meant to do in my office were, I put on my waterproofs and set forth. The first evidence for a renewal of activity was the repaired parapet to the man-made dam that the Scottish Government's agricultural department's (now SGRIPD) inspector had asked me to instal back in 2002. Clearly a beaver had carried out this work and the water behind the dam had been raised to its former level.



I walked on. The beds of water cress are splendidly abundant: I found a place where a beaver had been consuming some of the plants.











The willow that was cut in the years 2002 to 2004 is growing apace.












While I was standing near the old artificial lodge that Roy Dennis and the Banticks built back in December 2001, I noticed a small brown bird, flitting about. It turned out to be a female reed bunting (Emberiza schoeniclus), a supposition that was confirmed when her mate appeared.
























On my way out of what I have come to call the Wet Wood I crossed this small canal that the beavers dug some years ago. As you can see, they have built a dam using stones mostly.


I was pleased to see that the beavers have resumed operations in their original enclosure because I have always wondered why they should have moved downstream, given the apparently greater abundance of food plants, including willow in the Wet Wood.


I had meant to write something more in the way of 'Reflections on my paddle down the Dean Water', but that will have to wait for another post.


Sunday, 7 June 2009

A Paddle down the Dean Water





On returning from the Royal Scottish Forestry Society's Annual Excursion (which took place in Aberdeenshire this year and was very interesting) on the evening of Wednesday, 3rd June, I realised that it was time for another excursion of an entirely different kind.














So, on the 5th June, I set off from just downstream of Glamis to paddle down the Dean Water to its confluence with the River Isla. The Google map above left of this shows the GPS waymarks that I made on this journey. The weather forecast was for occasional heavy showers of rain, so I took my waterproofs. The forecast was correct, so I kept dry and comfortable throughout the journey. Hail fell as well as the heavy showers of rain.


Signs of beavers were apparent all the way down, some probably at least two years old, perhaps more. There were not many fresh signs of activity near Glamis, but more further downstream. Herons flew up, warblers drilled at me, mallards rose into the air and a pair of mute swans swam ahead for much of my journey. House martins, sand martins, swallows and swifts flew about. Little trout jumped from time to time. Streamers of water crowfoot (Ranunculus fluitans) flowed in the current and I looked with delight at their delicate white flowers. It seems that water crowfoot is native to the south of Scotland, but has been spreading north. I saw plenty of it in a tributary of the River Don, when I visited Aberdeenshire last week.

Salmon fishers do not like this plant because they can get their line tangled up with it, so research is being undertaken to find a herbicide that will destroy the plant but not the fish.…

Time was getting on when, suddenly, my attention was caught by some apples that had been skewered on slender willow stems. Someone was baiting the place with a view to setting a trap for the beavers. There were more apples, as well as carrots, a few metres downstream.


I paddled on and caught up with the swans, who guided me over a weir. That is to say that I noticed which way they went and followed them. The same thing happened last year when I undertook the same journey. May 2008 was dry and the swans walked down the sloping downstream face of the weir. This year it was possible to shoot it. Unfortunately I lost sight of the swans as I concentrated on the weir and didn't notice how they had tackled the rest of the system. All went well, however, and I made it safely to Crathie Bridge.


Today I returned to the banks of the Dean Water overland and found the baiting site and a lodge.

A trail camera had been set over the lodge.









Here is an apple impaled on a willow wand. The apple has sunk, waterlogged, I suppose.












The history of the Dean Water is that Forfar Loch, which used to spread from the town of Forfar nearly as far as Glamis Castle, was very largely drained on the instructions of the Earl of Strathmore of the day during the eighteenth century. The Dean Water was canalised to carry the water away and was deepened to take away the water from inflowing ditches in the catchment. Much of the ground currently drained by the Dean would revert to wetland if maintenance of the ditches was abandoned.