Saturday, 28 May 2011

Ragwort conservation ecology

First of all in this posting. Just to recap, ragwort is a problem in hay, but as is explained in this posting about a piece of real ragwort nonsense, they avoid it elsewhere. Animals are designed by nature to avoid poisons, and the poisons in ragwort are present in 3% of all plants most of which we never hear about. We don't have all the campaigning, the commercial outfits making false claims and the accompanying hysteria about the others. We know that ragwort poisoning is rare. We know this because of the research.

The purpose of this blog entry is to deal with the latest piece of misinformation that has appeared on a facebook discussion group. It repeats a couple of falsehoods. Firstly you get this comment from one user

You have to report it

This is most certainly NOT the case.

It is dealt with on this blog entry and chapter and verse is given from the mouth of a government minister on this entry about "Notifiable weeds " ( There is no such thing in the UK.)

The second claim made on that forum is more complicated, but the answer is just as clear.

Most entymolologist (sic) probably wouldn't view the loss of ragwort habitat due to grazing land management as detrimental.

If an entomologist were at all knowledgeable about ecology and population dynamics then he or she would be very concerned.

First of all before I explain the science you have to realise that this goes much wider than ragwort. The unnecessary panic about ragwort means that, as has been documented, plants get misidentified and targeted and also the general spraying, ploughing and general agricultural intensification it causes affects all wild flowers and the wildlife dependent on them.

The central concept here is calles by some wonderfully technical words "Metapopulation dynamics." Metapopulation is one of those words that we wildlife specialists like to come up with. It is half Greek and half Latin, but the general idea is quite simple.

Wildlife of all kinds tends to exist in patches of habitat and the survival of any of the species depends on how close these patches are to each other and how many of them are close to each other.

So we have this patchwork. If you start taking pieces out of the patchwork you start destabilising them. Losing chunks of habitat has an effect beyond just losing those chunks. The loss effects all the habitat in the surrounding area too. A central feature of this is that an organism can be extinct before all the habitat is gone.

I am simplifying things a bit but this is the essence of the issue here. You can read up further if you like. One of the standard textbooks actually has a whole chapter on an aspect of ragwort metapopulations but be warned it has been used as a textbook on a course for a Masters level degree. It is the sort of thing that wildlife nerds like me take to bed. (Actually I am really a sociable extrovert, but I do like my science books!)

This is one of the reasons we are seeing massive declines in UK wildlife. We have lost a third of our moths since the later 1960s, we see declines in birds too and all because of the decline in habitat.

It is worth mentioning at this point that many rare insects live on common plants, this includes ragwort. They have complicated requirements. Ecology is like that. The presence of a species may depend on many factors, site dryness, wetness, sunshine ,shade, the absence of food for other species that are affected by the same parasites or predators etc. etc.

Now to recap and explain. The loss of any habitat, including that on grazing land has a detrimental effect. We know this for certain because of all the research that has been done. We know this because of central tenets of modern biology.
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Thursday, 26 May 2011

What utter tripe!

I picked this up from a posting on facebook page put out by a Cumbrian horse group. It is a prime example of how hysteria about ragwort spreads.
The site starts with:-

Ragwort poisoning is one of the most common causes of plant poisoning in equines.

Anyone who can use proper critical thinking skills should stop and ask a few questions at this point. The first is how common is poisoning in general in animals?
Well actually it is extremely difficult to know. The reason being is it is rare.

This is one of the things that started me looking at this in the first place all those years ago when told that lots of animals were dying I immediately thought of the science and immediately thought there is something wrong with that claim.

You see we have known for the last hundred and fifty odd years that animals that do silly things like eat poison do not have as many offspring as those that don't. Since offspring resemble their parents any animal will have been shaped by nature in such a way that it becomes part of their nature to avoid eating poison.

Even to us human animals ragwort tastes nasty. Our taste systems have developed in such away that we detect the poisons as nasty. This is hardly surprising since the poisons in ragwort actually present in 3% of all plants. You may well ask why we never hear about all the others?

It sounds a simple idea, but it is one of the fundamental principles of modern science. So much so that the man who came up with the idea is so idolised that if you are British you are probably carrying his picture in your wallet!
The idea was developed by Charles Darwin whose picture is on the Bank of England Ten Pound Note.

What we do know is that ragwort is only a problem in hay and that ragwort poisoning is rare. When you look at proper studies and not hysterical claims of thousands of deaths you see that this is true. As an example, ragwort hysteria spread to the Netherlands, there has been a survey running there that has not had one single confirmed case of ragwort poisoning in a horse since 2007. This is in agreement with what we might expect from other studies.

The real piece of hogwash on this website however, is this:-

A horse or pony can be poisoned by ragwort without even having any plants in their grazing area. Seeds from ragwort plants in neighbouring paddocks and fields can be blown across and contaminate an area apparently free from ragwort. A horse or pony can inhale or eat these seeds and become affected by cumulative poisoning.

I try to write this blog with a dispassionate style as reflects the proper nature of the science behind it, but on this occasion this piece of prose deserves to be described properly.


When you have been studying the subject for a long time these things become really obvious. The person writing this appears to have no understanding of the biochemistry involved at all.

Firstly, whilst it is true that ragwort poisoning can be cumulative. The lethal dose is so high that it is often measured in percentages of body weight. The dose is minuscule!

Secondly, if you look at the biochemistry you can see the impossibility of this kind of poisoning. The toxins in ragwort are not actually poisonous in themselves. They have to undergo a conversion process. Some are destroyed in the digestive process. Some will be excreted unchanged. If they get through this then, and only then, they are converted into the breakdown products are they toxic and then those breakdown products are so reactive that they will react with anything ion the cell. It is only those that reach the DNA in the cell nucleus that have a toxic effect and then if the damage is minor which it certainly would be, there are DNA repair mechanisms which would likely nullify any damage.

Oh and of course there is the third point, unlike the claim on the website that they are dispersed widely by the wind. Ragwort seeds don't blow very far. Most sit at the base of the plant and the rest are almost without exception deposited within a few yards.

There is then the obvious fourth point. Horses inhaling seeds? How often do you as a human animal inhale any old seed that is wafting around? Well If you did you would soon cough it up. This is just hysterical hyperbole.

Of course now it has been posted on this horsey facebook page more people will be frightened and more hysteria will be generated. To be fair this is rather a common claim on websites and it seems that critical thinking on this issue is very much in short supply.
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Wednesday, 25 May 2011

Is this wildlife trust damaging a nature reserve?

When doing the regular research for this blog it is often necessary to dig a bit after finding the initial information. One of the problems you discover is that the hysteria over ragwort has even infected conservation organisations who should know better and you find them saying things that are incorrect. This causes more damage to biodiversity because people believe what they hear and act accordingly. It becomes a vicious circle, breaking which is one of the aims of this blog.

This was the case with a Hampshire and Isle of Wight Wildlife Trust blog which says

"I have been planning how to tackle the ragwort growth, it is not going to be easy as it is further ahead than usual and so many areas cannot be done as there are still nesting birds. Of course there are those that say it should be left as a nectar source and it is true that is it a valuable nectar plant. However it is toxic to stock when dry, although they avoid it when growing as a rule. We have to try and stop it spreading onto our neighbours land and it can also become very dominant on the dry disturbed soils around the old gravel pits, which is undesirable for other reasons."

Now much of this sounds reasonable, but the seasoned expert will notice this line
"We have to try and stop it spreading onto our neighbours (sic) land"

It is difficult to be sure but that sounds like a repeat of the old chestnut of a falsehood that the law on ragwort requires you to prevent the spread of ragwort. Even if it wasn't intended, this loose use of language would only serve to reinforce this common misconception. This then encourages loss of biodiversity on other sites, as people believe they need to comply with non-existent legislation. Like this example.

The thing that is really bad about it though, is that it encourages people to think that ragwort spreads easily. It most certainly does not. The research is very very clear. Most of the seeds fall at the base of the plants and the remainder in all practical terms only go a few yards. See ragwort- how far do the seeds disperse?

The digging around for information only confirms the fear that this Wildlife trust may be being mislead into damaging its own nature reserve. It turns out that they are carrying out ragwort control in a number of places on this massive 500 acre site. It may be necessary and reasonable but what is unnecessary is to harm other people's conservation work by suggesting falsely that ragwort spreads easily.

Perhaps if you are a member of the trust and are reading this you would like to raise it with them? Chapter and verse debunking the myths and providing the science is available on the Ragwort Facts site.
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An example of misinformation countered

A few weeks ago a story appeared in a local newspaper

A NEW menace has sprung up at Apex Park in Highbridge - ragwort.

The Friends of Apex Park have taken action against the growth, which has affected the wild flower meadow.

A sub-group, under the leadership of Patrick Stokes, has been using organic sprays on the ragwort, which can be dangerous to horses and cattle.

This is a nature reserve and the matter was mentioned on an on-line discussion group.
One of the members contacted the local council who it turned out misunderstood the law on ragwort and the guidance ( which is pretty badly done anyway) and they realised that they did not need to control the ragwort. Unfortunately before this information was countered more people would have been mislead by the article in the newspaper. It is the constant stream of poor stories in the press, often put there by vested interests, and the repeating of this on websites that leads to more unnecessary damage to biodiversity.
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Monday, 23 May 2011

Welsh Assembly did do it

This story was covered in a previous posting It turns out that the Welsh Assembly Government has been putting out false information on the law on ragwort.. They claimed that there is a statutory responsibility on landowners to control ragwort . This is simply untrue.

The story appeared in the Western Mail and prompted this letter on ragwort in response.
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Monday, 16 May 2011

A worrying story from Cornwall.

The errors are coming in thick and fast over the last few days.

David Breer's interesting blog The scientific study of plants

Also, I have a message from a gentlemen in Cornwall who has
found a poster in his post office to the effect that five species of
weeds must be destroyed if you have them on your land.

and he continues,

My Cornish correspondent is concerned because already the local churchyard has been sprayed, to the detriment of other species.

And the comments on the blog are even more worrying they are full of people who misunderstand the law on ragwort and who believe that it is far more dangerous than it should be.

Seriously worrying is the fact that now other plants which, like, thistles are valuable nectar sources. The Weeds Act 1959, which is really an anachronism that was never enforced until the campaigners generated hysteria, doesn't make controlling these plants automatic and compulsory. I cannot see how many churchyards would require controlling even under the poorly thought out guidance created by DEFRA.


After writing this blog entry I find that the blog I am quoting doesn't belong to David Breer at all. On attempting to dig out the author and follow up on the poster story I found that it is a site that very cleverly takes information from on-line discussions and converts them to look like blogs. In this case the discussion, although marked as recent, is in fact a discussion from a few years ago. The text I quote is quite genuine it just isn't recent.
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Scarborough Council unfair to ragwort and biodiversity

Are you going to Scarborough Fair? So go the words to a famous song.
Well perhaps there is no fair selling things there now but the local council
is certainly not being fair to the biodiversity supported by ragwort.One of their documents on-line contains the following piece of claptrap.

It is one of 5 species listed as a Noxious Weed in the 1949 Weeds Act and it is an offence to allow the plant to proliferate on your land and spread to adjacent property. The Ragwort Control Bill (2003) has recently been passed to strengthen this.

It is hard to know where to start with a statement like this. It is so full of inaccuracies. So I will take them in the order in which they occur.

First of all the term used in the Weeds Act is "injurious weeds". It means in this context weeds that are harmful to the interests of agriculture. Follow the link to find a proper explanation of the derivation from Latin of the word "injurious".

Then it is the Weeds Act 1959 not 1949. It is most definitely not an offence
under the weeds act to allow the plant to proliferate on your land!

Finally all the Ragwort Control Act ( Act is the correct word for bills that have passed!) only tells the government that it can produce some guidance.

There is an earlier blog entry explaining the law on ragwort.

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Sunday, 15 May 2011

It even crosses the Atlantic now

This is an entry from the blog Dog-Apparel which is from Florida

"The most poisonous plant in Britain to horses is Ragwort. Don’t know if this helps, it is now a "notifyable" (sic) plant and if you see it you are supposed to pull it up."

Ragwort is not a notifiable weed in the UK. There is no such thing in UK law. It is also questionable if it is the most poisonous plant. There are certainly plants that are far far more deadly.

Also you should not pull up ragwort where ever you see it, as this is a criminal offence under the 1981 Wildlife and Countryside Act, unless you have the
owner or occupier of the land's consent. See ragwort is sometimes protected for more details.

There is a common problem with people thinking they are doing good by pulling up ragwort. Living ragwort is ignored by livestock. Dead ragwort is a different matter. By pulling it up an leaving it you may be endangering animals. There is also the problem with other plants which are not ragwort, being misidentified

Ragwort is an ecologically important plant and there are cases where habitats on
nature reserves have been damaged by its removal by well-intentioned but
ignorant individuals, who, like the writer of the Dog-Apparel blog have read something incorrect somewhere and who have just repeated it.

This blog Eco Holidays and Adventures puts the whole thing very succinctly in regards to ragwort with the comment:

So, when you are out exploring the countryside – think of their trees as you would of your garden fence; their plants as you would of your rosebush; their gates as your own front door.

Would you want someone to leave your front door open, break down your fence and snap your rosebush in half?

I didn’t think so…….
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Saturday, 14 May 2011

Even vets can be wrong

"There's nothing so absurd that if you repeat it often enough, people will believe it."
So wrote William James the famed philosopher who is often regarded as the father of modern psychology.

This is an entry from the blog of vet Paul Proctor MRCVS

"Ragwort is a common weed that grows throughout the British Isles, and has always been a problem but recently it has become apparent that the weed may be getting out of control and potentially posing a real threat to the horse population."

The article is good in other respects and Mr Proctor seems to be a perfectly fine vet. However, on the basis of the FACTS, I have to disagree with that statement.

There is no evidence that Ragwort is "getting out of control". There is no evidence
that it is increasing. If anything the evidence from the government's
UK Countryside Survey is that Ragwort is decreasing. At least he has the good sense to use the words "may" and "potentially".

What there is a lot of evidence of, and the reason for this blog, is a concerted campaign of misinformation and falsehoods. These are often promoted quite innocently by people who just do not know the facts and who are unnecessarily frightened. Sometimes they are promoted by commercial companies with a product to promote. Sometimes by organisations who need to raise their profile, and who do so by putting scary stories into the media.

The story that ragwort is increasing is, in the face of the facts, absurd, but as William James said it is been repeated often enough that people will believe it.

The problem with vets believing that ragwort poisoning is common, rather than what the literature indicates, that it is rare, is that it manifests itself like any other type of liver damage that is from other causes.

There is a risk, if vets believe that ragwort poisoning is more likely than it is, that animals will suffer as a result of misdiagnoses.

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Friday, 13 May 2011

Welsh Assembly Government giving incorrect advice?

Let's hope the Welsh Assembly Government, known universally as the WAG, haven't made this mistake. The website of the magazine Smallholder is running a story about the WAG saying,

"The Welsh Assembly Government wishes to remind all landowner/occupiers, Local Authorities, Trunk Road Agencies and Network Rail that they have a statutory responsibility to prevent and control the spread of ragwort under the Weeds Act 1959. "

This is definitely incorrect. They are , like many public authorities, wrong about the Weeds Act. It most clearly doesn't place any automatic statutory duty on anyone!

The story hasn't turned up elsewhere so it may not have gone generally to the press. Even so if they have been putting out this falsehood I can think of some people who will be dogging the WAG about it!

The WAG has a legal responsibility to promote sustainability by putting out this misinformation they are encouraging people to destroy a valuable resource for biodiversity. What about the wildlife that depends on this native plant. What about the other misidentified plants that will be destroyed. As was documented recently.

Just in case there is any doubt about the law on ragwort , you can read the full text of The Weeds Act 1959

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Thursday, 12 May 2011

Are the hedgehogs affected?

There are some interesting comments on this Hedgehog forum. Someone is worried about the effects of a weedkiller sprayed for ragwort on hedgehogs. It is always difficult to be sure of these anecdotal cases but one thing we can be certain of ,less wildflowers, ragwort and others, means less insects and less food for the poor hedgehogs.
The panic over ragwort has general effects on biodiversity which we should keep aware of.
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Wednesday, 11 May 2011

These misidentifications are far too common.

One of the big problems with all the undeserved panic about ragwort is that other wildflowers get targeted. We get gangs of workmen going out to clear road verges and all yellow plants are going to suffer. These guys are not botanists. Not of course that the evidence shows that ragwort seeds blow around much and that roadside plants are a risk.

Ragwort hysteria has spread to the Netherlands where this latest beauty complete with picture comes from. The article is of course Double Dutch to most people but it talks about the plant being a risk to children, which of course it isn't in any real terms at all.

This picture from the article isn't ragwort of course. It looks as if it is a hawksbeard or something similar.
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Sunday, 8 May 2011

Milton Keynes council also gets it wrong

Continuing the theme of Councils that get things wrong here is Milton Keynes Council

They say with relevance to ragwort:-
The Weeds Act 1959 requires that five specified weeds are controlled.

This is of course not true.The law on Ragwort is quite clear . It does not automatically require that ragwort is controlled. It just lets the government order people to control it when it is a problem.

The problem here, like many side effects of ragwort hysteria, is that other wildlife is also being harmed in the process of unnecessary ragwort control. A look around the council's website shows that they are using it as a justification for overmowing all roadside verges.

You can also find reference to this council's error here. Milton Keynes Council ragwort errors
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Tuesday, 3 May 2011

Notifiable plants or weeds: There is no such thing in the UK

Local councils are often caught up in the panic about ragwort. There are many many errors. Eastbourne Council are a good example.

They have Ragwort listed as a "notifiable plant". This is a common error. Often it is "notifiable weed". One thing should be made clear. There is no such thing at all in UK law. There is no need to notify anyone about ragwort or any other plant being present anywhere. You are also not automatically required to control it. For the law on Ragwort you can see this previous posting The Law on ragwort: the legislation explained.

In Eastbourne council's case they compound the panic by claiming that ragwort would contaminate compost. This is a rather silly notion.
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Sunday, 1 May 2011

Ignorance and bigotry in the face of science

One of the problems encountered when trying to communicate the science of ragwort to the public is ignorance (In the sense of lacking of knowledge). Whenever you go on line and enter a forum you will find someone who is ignorant but just knows that they know it all better than you do.

One of these problems was recently encountered by a well known European expert on Ragwort, Esther Hegt from the Netherlands. A keen horsewoman, Esther runs one of the best websites in the world on the subject and it has an English language version Ragwort Myths and Facts. It is stuffed with facts and figures all gathered from a documented list of expert sources. Much of her most important information is co-authored by a leading ragwort scientist Dr Pieter Pelser who actually has a Phd on the plant!

The website contains a great deal of information for dispelling the panic over the plant and the panic originated in the UK which is why the English language section was developed. This Netherlands hosted site does not get well listed in UK search engines which is a great pity.

Unfortunately, when trying to explain things on-line she can get attacked and one vicious and bigoted example comes from the forum of our old friends Horse and Hound. A hotbed of "horsteria" over ragwort.

Trying to explain the facts to some people there this leading expert gets told "to take her ignorance back to France" ( which of course isn't even where she comes from!) The irony is of course it is the attacker who is not just ignorant but bigoted as well.
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