Sociable

Saturday, 30 April 2011

Spring!


We stopped for a walk along a short length of the Perthshire River Garry earlier this week, wondering if we should see signs of beavers. Instead, we found this Solomon's seal. I suppose it is an escape from a garden. It doesn't look like the rare Whorled Solomon's seal. 

The Garry is part of a project to restore water levels to a point where the river can once again support salmon. I wonder how it is progressing. 


Further on we noticed a couple of morels. I was excited to see the fungus, a first sighting for me, and resisted the temptation to pick it. 



We have been watching beavers a good deal lately and I wondered how the bogbean was faring this spring. Here is a photograph of one of the plants in flower. 

I had hoped to put up a link to You Tube of some clips of beavers feeding and swimming about, but I cannot remember how to transfer bits of film from my Sony camcorder to my Macintosh laptop.

Sunday, 17 April 2011

Watching Beavers at the Big Pond

'Spring is here' in the words of the immortal mathematical songster of Harvard, but we will not go poisoning pigeons in the park or any other light-hearted activities that appealed to Tom Lehrer.

I went out beaver watching this evening. This time of year is particularly good because the vegetation has not grown up on the rafts of sedge and so, although beavers can hide in the rushes, there is still plenty of open ground.



I think I saw five beavers this evening, but it is not always easy to know. Beavers can move swiftly from one feeding place to another, which makes it difficult to count them if you are on your own. 

Of course, if you trap them all, puncture their ears with colourful tags and pierce their tails with radio transmitters you can probably get a fairly good idea of how many you have and where they are, but run other risks. As Rob Thomas of RZSS told his audience at the talk he gave the Edinburgh Centre of SWT the other day, some beavers in the Knapdale project tried to tear the transmitters out of their tails. If that isn't stressful for the animals I don't know what is. The new approach is to stick radios on the lower rump, which must be better, but still be risky to a beaver negotiating a narrow way among some branches of a fallen tree under water.


And now for another photograph - 


Fading light is a particular difficulty with digiscoping and the shutter speed in this photo was about 1/10th of a second: no wonder the result is a bit blurry.


Friday, 15 April 2011

Evening grazing


Digiscoping for the first time this year, running out of battery with my Canon Ixus, resorting to an iPhone. 


Failing light and a trembling hand make it difficult enough to take a reasonable photograph without the added hindrance of lack of practice.

Still, I think I saw as many as four beavers. They are very hungry at this time of year and the fresh growth is just beginning, so there is little to hide them if they sit on the sedge rafts. The two in the rushes have more to conceal them.

Thursday, 14 April 2011


Yesterday evening we attended our now monthly meeting of the Scottish Wild Beaver Group. We had a useful and news-filled evening because this was the first time that we had met since the Freedom of Information papers reached us. We spoke, too, about our meeting with Rob Thomas and Roisin Campbell-Palmer of the RZSS and, following from that the publication of the results of the autopsy on Erica.

Crossing Allan Street in Blairgowrie after the meeting I saw this newspaper billboard: a classic of its kind and interesting because there is no need to explain who Erica was to the people of Blairgowrie.

Petri Nummi, a Finnish zoologist with a particular interest in beavers, has kindly sent me a paper on beavers and their relations with bats.

UNCORRECTED PROOF
1 ORIGINAL PAPER
2 Bats benefit from beavers: a facilitative link
3 between aquatic and terrestrial food webs
4 Petri Nummi Saara Kattainen Paula Ulander Anna Hahtola
5 Received: 2 November 2009 / Accepted: 28 December 2011
6 Springer Science+Business Media B.V. 2010
7 Abstract Bat populations are declining in many areas, partly because up to two-thirds
8 of their wetland habitats have been lost. One natural agent creating wetlands is the
9 beaver, which is recolonizing its former range. Beaver flowages are known for their high
10 production of aquatic invertebrates. We tested the hypothesis that the high numbers of
11 insects emerging from beaver flowages influences their use by foraging bats. We com-
12 pared bat use and bat numbers above flowages of introduced Canadian beavers Castor
13 canadensis and in nearby control ponds where beavers were absent. The two bat species
14 detected, Eptesicus nilssoni and Myotis daubentoni, used beaver flowages more than non-
15 beaver ponds. This is especially the case for Eptesicus nilssoni. Bats also seemed to
16 forage in larger groups while above beaver ponds compared to the control ponds. Beaver
17 flowages appeared to improve bat habitats. A plausible reason for this could be the high
18 number of insects emerging from beaver ponds. Favouring the beaver in habitat man-
19 agement is a tool for creating suitable conditions for many other species, such as bats. In
20 areas not suited for the beaver, insect production can be achieved by imitating the beaver
21 with man-made impoundments. This is especially important in areas which have lost most
22 of their wetlands.
23 Keywords Bat conservation  Beaver  Emerging insects  Eptesicus nilssoni
24 Facilitation  Foraging habitat  Myotis daubentoni  Wetland management
25 Introduction
26 Bat populations are facing serious declines in many countries. This decline is largely
27 due to human-caused habitat loss and modifications, affecting both the roosting places
28 and feeding habitats of bats (Daan 1980; Walsh and Harris 1996; Hutson et al. 2001).
A1 P. Nummi (&)  S. Kattainen  P. Ulander  A. Hahtola
A2 Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland
A3 e-mail: petri.nummi@helsinki.fi
123
Journal : Small 10531 Dispatch : 31-12-2010 Pages : 9
Article No. : 9986 h LE h TYPESET
MS Code : BIOC2686 h4 CP h4 DISK
Biodivers Conserv
DOI 10.1007/s10531-010-9986-7
Author Proof

Here is the abstract and a sentence or two of the introduction.


Tuesday, 12 April 2011

Aspen and a Peacock Butterfly

Victor Clements of Scottish Native Woods offer of a dozen aspen from different clones around the Highlands was an exciting and welcome one. Last Sunday Victor came here with another of our Scottish Wild Beaver Group members, Tina and her son Mungo, and we planted two of these small saplings. The photo shows my grandson, Adam, helping Victor plant one of them.

The link is to a blog site that deals with aspen and has some more photographs of this auspicious occasion.












 Louise drew my attention to this Peacock Butterfly, sunning itself on a warm afternoon.

The news that Erica died of septic shock comes as little surprise. She was stressed, suffered an injury, her immune system was weakened and she died. That's what they call best practice, I suppose.



Thursday, 7 April 2011

Externalities and Grey Willow

The name of Jules Pretty came to mind recently when I received an email from Chris Spray, professor of Water Science and Policy at Dundee University.

Here is a quotation from part of Chris's email.

'At a UK scale the total cost of environmental externalities arising from agriculture has been estimated by Jules Pretty at Essex to be roughly £2.3 billion - contamination of drinking water with pesticides is estimated to cost £120million/year, with nitrates £16m, and phosphate and soil £55m. The cost of damage to wildlife, habitats, hedgerows and dry-stone walls was estimated at £125million, from emissions of gases £1113m, from soil erosion and organic carbon losses £106m and from food poisoning £169m. Huge figures, and this doesn't even consider the more recent interest we have in Scotland in such areas as flooding and flood risk reduction.'

This problem of the externalities is one that affects us all. At one level you may see the problem as one in which individual farmers and landowners profit at the expense of the rest of the community. At another level it means there must be recognition that rivers cannot be treated merely as drains in the winter and sources of irrigation water in the summer. There have to be solutions that make sense for us all and the environment on which we depend.


Nearly every year there is some planting of trees to be done, so when I order the trees I include some extra ones. This year, in a moment of enthusiasm, I ordered 100 crab apples and 1,000 willows. I have just spent a rewarding hour planting one hundred grey willows. In the past I have planted at rather wide intervals: two paces apart, but while in Oregon in February someone talked about the importance of planting at close spacing. I have been planting at about one pace apart today There is no doubt that the roe deer will get some of the saplings, but some should survive, and that is the main point. 



Here is the lowest of the big dams. Grasses are growing along it already. Soon there will be cress. 


Below the dam I see clean gravel. The sediments that ran off the fields have been caught by the dam.

Tuesday, 5 April 2011

Freedom of Information

Home from London and I see the daffodils nervously coming into flower. They are fully out in Perth and in London the gardens of Islington were full of brilliant magnolia.


Our chief excitement on returning home has been the reading of the package-full of Freedom of Information documents, received from SNH, about the free beavers in the Tay.






What dread secrets are they hiding?

Thankfully the programme of capture, ineffective as it was, has been abandoned. 



I came across this much pockmarked snag in a plantation this evening.

Friday, 1 April 2011

A Break in London

Away for a break in London; a change, you might think, and so it is physically speaking, but laptops, Google, facebook and twitter, mean that we are yoked to the same tasks and projects.

News has reached us that Erica is dead. She died in Edinburgh Zoo, having not taken well to captivity, it seems. So much for the curious notion that the free beavers of the Tay were being captured for their own good.

In his obituary for Erica on the Scottish Wild Beavers Group blog, Paul Scott speaks of Erica as being one of the first beavers to be born in the wild. This is not quite right: it is very likely that beavers have been breeding in the Tay and its catchment since 2001.

Roseanna Cunningham said, at the second Brian Taylor 'Big Debate' in Perth (was it the 17th or 18th of March?) that policy could not be decided on 'cuddleability'.

Here is an interesting link about flooding at Belford in Northumberland in 2008. The report recommends the kind of management that beavers do for nothing.

http://research.ncl.ac.uk/iq/download/BelfordBHSpaper.pdf

Having said that, I should recognise that beavers have their own approach to what constitutes a desirable landscape and this may not coincide with what humans would like but, as we know from the experiences of others, there are solutions that enable beavers and humans to coexist to both species' advantage. And, of course, to the great benefit of many other species.

And here is a link to YouTube, which shows the morning after the floods at Belford of September 2008:

http://www.youtube.com/watch?v=dYYbCVMhk0g


A windblown sycamore, whose bark beavers have been eating. The tree has been dead for two to three year: I suppose there must be some nutritional value in the lichens and mosses that are growing on the dead bark



 An otter's track in the silt.



Freshly stripped twigs by one of the Burnished dams.