ragwort outbreak panic up north

Today's entry is abut a ridiculous article that appeared in the Northern Echo

Apparently there have been "ragwort outbreaks in Weardale". One does wonder if there have been outbreaks of daisies or dandelions. This sort of language suggests that ragwort is spreading when we know that it has been there all along and that it is , if anything, declining in abundance. It quotes a local Cowshill resident Ian Reedman.

“It is poisonous to horses and potentially to humans. People need to be aware of it and report it to the authorities. The only way to get rid of it is to pull it out of the ground."

To those of us in the know of course this panic seems rather foolish. There is no reason to panic about this native wildflower as it is only rarely any problem. Oak trees are poisonous too but we don't panic about them. Ragwort is a bit more poisonous but there are no records of anyone every being poisoned in the UK.
You would have to eat quite a bit of it and horse problems as I blogged this week seem to be rather exaggerated. and when the exaggerations were examined by the Advertising Standards Authority adverts were stopped

It is the silly season and with all the politicians on holiday we get this nonsense every August.

More foolish ragwort comments from an equine professional

A while ago I posted an account of how the BBC had encouraged law breaking on ragwort.
and that they had broadcast a statement from someone who had contacted them making the silly claim that ragwort was not a native plant.

I regularly post accounts of how equine professionals seem to  make silly and ignorant statements on ragwort. Like this one where a vet posts a link to really nutty material or this one on the same nutty material and on getting the law wrong. and as I have blogged before  it seems even an equine veterinary professor is not beyond making quite serious mistakes.

Well I have tracked down the originator of the statement. He has, it seems, been bragging about it on facebook on a page commenting about the BBC programme.

Richard Halls Had my say last night, one group was saying ragwort was ok. I said its[sic] not native coming from South America and was spread by the railways.

Mr Halls is of course wrong. The ragwort in question is a native plant. He will have quite well have had botanists groaning around the country at this foolish ignorance. There is a ragwort that is reckoned to have spread around the railway network but this is a very different and smaller plant called Oxford Ragwort. It doesn't come from South America but from Mt Etna in Italy.

But the facebook account reveals more. He is an Equine Dental Technician. This is is yet another example of the phenomenon, perhaps caused by the nonsense in  the press,of an equine professional not knowing their stuff.

 

Who tells the ragwort truth?

Today's blog entry is inspired by the following tweets.

Man in Black ‏@Asatru69 3h

Over 2,000 horses die a year as a result of RAGWORT poisoning. Time to completely eradicate this horrible plant.

And then after being  pointed to an article saying this wasn't the case by ragwort expert Esther Hegt

Man in Black ‏@Asatru69 2h

@Ragwort_horses There seem to be as many articles 'for' Ragwort as there are from those 'against'. Who is telling the truth then?

How do we know what the truth is? Well we use the scientific method and evidence. With the 2000 horses figure we can actually show that these figures were examined in advertising by the Advertising Standards Authority.(ASA)

They are independent body who look at the evidence. Those adverts are no longer there because the ASA took action and the companies could not provide the evidence.

( That blog entry talks about the nonsense figure of 6500 deaths but there was one company saying 2000)

The problem is that there are two groups of people involved. There are people like me and Esther who look

at the science and there are people who just repeat what they have been told.

On Twitter Esther advised asking the University of Liverpool. The death figures are often claimed to be from data collected there.  As she knows I have already checked with them they recorded not one single death over a five year period.

Anyone wishing to do so can read about the circumstances surrounding this at a blog entry I made this week.

In regards to what happens if you look at the scientific evidence Esther Hegt is a prime example.

She once  believed the nonsense , but she is a good scientist and looked at the evidence.

It is the evidence that says it is nonsense.

Lynne Allbutt should read about ragwort

One of the really frustrating things about this work is the monotonous regularity with which journalists publish nonsense about ragwort without  checking the facts. A particularly bad example appeared in a column in the Western Mail written by Lynne Allbutt recently. Particularly  because she gives a source which debunks a claim she makes in her column. Despite giving it out to her readers she doesn't seem to have read or understood it.

The column seems to make error after error.

 It is toxic and a particular worry for horse  owners as ingestion of either its green or  dried state can cause serious liver damage,  which can have tragic consequences for  animals.

Here we go again! We know from the data that ragwort poisoning is actually very rare. An animal hospital , which is  recognised as a centre for such things recorded no cases at all for five years between 2006 and 2011.  (These are the only years for which data has been provided)  We know very very clearly from biological science that every animal that needs to has evolved strategies to cope with the toxins which are actually present in 3% of all plant. We never hear fuss about the others and horses do not eat the green plant they have evolved not to do so. It is only a problem in starvation abuse cases or where it is eaten in quantity in hay.
 

 The Ragwort Control  Act 2003 (which amends the Weeds Act  1959), advises it is not an offence to have  these weeds growing on your land and  species such as ragwort have significant  conservation benefits.
 However, they must not be allowed to  spread to agricultural land, particularly  grazing areas or land which is used to  produce conserved forage.

 The problem here is accuracy for that act of parliament says nothing of the sort. You can see the full text of the Ragwort Control Act here

There is also a suggestion that the poisons  (pyrrolizidine alkaloids) can also be  absorbed through the skin if handled  with bare hands, although this has not  proven to be fatal. Knowledge is a powerful  tool, so for more information, visit  www.ragwort.org.uk

Knowledge is indeed a powerful tool. The problem is that that idea that you can be poisoned through the skin appears to be a silly nonsensical myth and worse still that website DEBUNKS IT.

You can read the page here


I understand that the author of the site ragwort expert Esther Hegt is rather perturbed that her website has been associated with the myth.

Esther, by the way ,is a horse owner who initially believed the nonsense about ragwort until she researched it.
She has gathered a stellar cast of international experts to help her write her website.  Her chief adviser on the skin absortption issue actually has a PhD specifically on ragwort.

The skin absorption myth is a particularly nasty and frightening myth. I know of an example of a teenage girl who was intensely and morbidly frightened because she was told after handling ragwort that it might kill her.

Ragwort An Open Letter to Alastair Stewart

Today's blog entry is prompted by several Tweets by Alastair Stewart a well known British journalist who is a newsreader on ITV.

Alastair Stewart  @alstewitn 19 Aug
#ragwort Professor Knottenbelt is right. There are more than enough other plants for insects to feed on. Ragwort,however, kills horses.

And in response to Dutch ragwort expert and horse enthusiast Esther Hegt

Alastair Stewart  @alstewitn 19 Aug
@Ragwort_horses He is right that Ragwort kills horses. Insects can feast elsewhere or evolve. Dead horses can't.

I have decided to write an open letter.

Dear Mr Stewart,
I have great respect for you as a journalist but I think that , on the basis of the evidence, that you are wrong.

The evidence very very clearly shows that the risk to horses from ragwort has been exaggerated beyond all reason and I believe since I follow the scientific method and use evidence that I can establish this clearly.

I would first of all recommend that you listen to Esther Hegt. She is a keen and devoted horsewoman from The Netherlands, a highly intelligent and technically minded woman who at first agreed with you, but after looking into the science she realised that the stories which had spread to her country from the UK were wrong.

 I hope that being a successful man in your field who has already shown signs on twitter of being open minded that you will hear me out and listen to what I have to say.

First of all let me deal with the subject of Professor Knottenbelt. It is important to realise that being a professor doesn't give him some kind of divine right to be correct in matters of science. In science it is the evidence that shows who is right. It seems very clear to me, after spending over a decade of detailed study, that he is very clearly wrong.

Professor Knottenbelt has played a pivotal role in this subject. I could choose many many instances of him being quoted in the press to make my point, but I am mainly going to concentrate on examples where we can be certain that he has been directly involved in writing the statements concerned.

One of those sources is a letter that he wrote to the Yorkshire Post about Ragwort  Jacobaea vulgaris (The old name is Senecio jacobaea). He said some rather strange things.

    In one circumstance in Africa where ragwort infusions were fed to humans as herbal remedies, the toll was very heavy.

    A very high number of cases of hepatic carcinoma were reported as well as extensive veno-occlusive disease and liver failure. The plant is toxic to people make no mistake. For example, cereals contaminated with ragwort in Uzbekistan were responsible for large numbers of cases of severe liver disease.

And later.

      In South Africa the plant is causing massive concerns.  

 This sounds very scary but I have checked these statements out. The alkaloids occur in thousands of different plants, 3% of all flowering plants in fact. It is doubtful that the plant grows anywhere in Africa except possibly the in the northern or Mediterranean coast area.  According to my extensive literature searches which reveal that all the poisoning cases are well documented, the known cases in both Africa and Kazakhstan were not caused plant in question, and the Kazakhstan cases were plants in a different botanical family altogether!

As for his comments specifically about South Africa, I have asked around the international network of ragwort experts that I am in contact with. The South African organisation that maintains records of their flora,  have no record of the plant ever being found there.  It seems that it clearly cannot be causing "massive concerns."

In the letter he says very odd things about ragwort's distribution.

    "It has taken over fragile eco-systems on the west coast and islands of Scotland, it has spread across the hills of Wales and the Downs of England."

This is baffling to ecologists who know the plant was always there and hasn't changed in distribution or spread to new parts of the country as he seems to imply. There is however,  a known psychological effect called, "The Bader Meinhoff Effect"  where people think something has become more abundant just because it is drawn to their attention.

Back in 2000 he wrote on the same theme in a conference paper,“Over the last 5 years there has been an explosion of ragwort in the UK."
He always seems to say it is increasing but we have pretty solid evidence that during that period ragwort was actually markedly declining.  There was an official government scientific survey. I don't quote figures or pass stuff on as the real  research data figures were supplied to me as a courtesy, but they would be available I presume to anyone under the Freedom of Information Act.

In that letter Professor Knottenbelt uses a peculiar  and seemingly entirely  wrong statistical method to derive the number of horse deaths. To explain it imagine an opinion poll to decide the way the voting was going for an election and then imagine that the survey was conducted exclusively in the local headquarters of one of the political parties. Do you imagine that you would want, as a journalist, to rely on such a survey? It is obviously not based on a representative sample.

To me Professor Knottenbelt's methodology is very similar. He takes a tiny number of cases from his hospital. where after establishing himself as an expert they are going to be especially highly concentrated and common and tries to extrapolate. You cannot do this as the sample is not representative of the UK's horse population. What is also puzzling and seemingly significant is that he says he gets "more than 10 per year" cases in the Yorkshire Post letter. I have done a Freedom of Information  request to his hospital. They told me me that over the 5 year period 2006-2011 which includes the time of his letter, they recorded no cases at all of ragwort poisoning in horses, NOT ONE!

It seems to me that the professor is rather too keen to exaggerate the problems of ragwort and the frightening tales he tells are open to question.

Now let me  turn to the subject of evolution. I will try to be brief and not quote technical papers although I do have them. These alkaloids are very common. Any grazing animal is going to encounter them in a variety of plants in nature and it is very very clear from the data that the level of resistance is proportional to the likelihood of them being in the diet. The mechanisms here are many and complex, special taste senses, digestive bacteria, different enzymes etc. A horse, just like any grazing animal, is going to have evolved enough resistance to cope with normal life and that is the conclusion that the science supports. If you actually at the published cases of horse poisonings, where it is confirmed as ragwort, which most liver cases aren't, where the circumstances can be established, it is always, it seems, either starvation abuse where the evolutionary drive is going to be,"if you are going to die it is worth trying anything", and when ragwort occurs in quantities in the artificial man-made product of hay. Horses have already evolved a tolerance to ragwort growing in normal  circumstances.

At this point I was going to explain why it seems to me that Professor Knottenbelt is wrong on the toxicology and why it seems very clear that ragwort is not always a cumulative poison but it is too technical and long-winded so you can read it here if you wish Professor Derek Knottenbelt an analysis of his conference paper 2000

Now we come to the insects. I don't think I need to say very much about this. Professor Knottenbelt is obviously a  veterinary expert,  but he is not an expert on insects and he is simply wrong. There are many species dependant on the plant. Evolution is a long process so they simply cannot move to other things.

It is also important as a nectar source for many others and I could give you a long detailed and technical explanation why over zealous ragwort control is a severe problem, but I think it is unnecessary.

Finally. two resources for you ,a detailed set of RagwortMyths , and the original of that letter in the Yorkshire Post. ( You need to scroll down.)







I hope now that you understand why your tweets caused the responses you got.

Yours faithfully,
Neil Jones

The Daily Mail hate article on ragwort

The Daily Mail recently published another of its nonsensical hysterical articles on ragwort featuring promenently the British Horse Society, one of the chief sources of bad information on ragwort.

It gets a bit repetativeThe British Horse Society as I frequently mention have a dreadful history of putting out nonsense, so much so that they took a hammering from the Advertising Standards Authority after one of their leaflets was stopped and people repeating their bare-faced inaccuracies also had their adverts stopped.

It starts  in the usual alarmist tones that we have come to expect from a newspaper that is nicknamed "The Hate Mail."

"It's sea of bright yellow blooms that makes a picturesque contribution to the British countryside.
But despite its pretty appearance, the ragwort plant poses a serious risk to horses - and it has infested the country, animal groups have warned.
The seed has spread and the plant, which causes liver failure in horses resulting an extremely painful death, is now flourishing across the country."

One does wonder if they think that it is an asylum seeker or something. For this native wildflower has not spread anywhere and the latest government figures show a marked decline.

After more nonsensical exaggeration fom the BHs we get this mangling of the law.

The Weeds Act (1959) and The Control of Ragwort Act (2003) advised that responsibility for controlling ragwort rests with the occupier of the land on which it is growing.

These laws do not say this. to cut matters short see the briefing on ragwort law.

Grooms' assocation ragwort mess up.

My attention has been drawn to a video from the British Grooms' Association entitled
"Pull Ragwort correctly and safely with the British Grooms[sic] Association"
Aside from the puzzling lack of the necessary grammatical apostrophe in writing the organisation's name, I am not impressed by their efforts

As I have  blogged before. It is not uncommon for equine professionals to have a less than perfect knowledge of the ragwort issue and this organisation seems to be yet another example.

It does not start well as it features Liz Daniels the organisation's director who rather irritatingly mispronounces the name of the plant ragwort.
The "o" in "ragwort" is pronounced like the "o" in "worse", and in "worm" NOT like the "o" in "horse"!
Indeed, the Oxford English Dictionary, the accepted authority on the vocabulary of the English language, refers the reader of -wort words to a special entry on the word "worm".

It says:-

"In this word, as in worse adj. and n. and wort n.¹, the spelling wo is an early graphic substitution for wu (compare Middle English wolf, wolle, wonder, for Old English wulf, wull, wunder), and this again is a reversion from Old English wy (i.e. wü) to the unmutated vowel through the influence of the following r. More normal developments of Old English wyrm appear in the Middle English (eastern and Scots) wirm and (south-eastern) werm."

This does not bode well  for the rest of the video, which one could retitle as, "How to propagate more ragwort plants." We are treated to a display of ragwort pulling where you can actually hear what seems to be the sound of ragwort roots breaking off and being left in the soil. Indeed the tiny tuft of roots that we see is entirely incongruous in relation to the size of the plant. This is important because root fragments are an important source of new plants. It is one of the strategies that the plants have for survival. While the presenter does say that you should get up all the roots, it is pretty obvious many are left behind.

One of the most important scientific papers on ragwort is entitled "The Biological Flora of the British Isles Senecio jacobaea"  Senecio jacobaea being the old name for what we now call Jacobaea  vulgaris or ragwort. and is written by John L. Harper and W.A.Wood. in the Journal of Ecology in July 1957.
These Biological Flora papers, of which there are many others, are special series of papers each on a different element of our wild flora and  each is an attempt to collate and explain what  is known of the ecology of  a plant.
They quote other studies and they say this about the roots of ragwort:-

"Poole and Cairns found 50 to 100 roots per crown on average plants in a cow-grazed pasture. These roots slanted down through the turf below the main mat of pasture roots to run horizontally at c. 10 to 12.5 cm. depth. Plants more than 2 years old had multiple crowns with 600 to 700 roots. The root system may extend much further than the aerial parts, especially in loose soil.
Regeneration may occur from root fragments quite unconnected with the shoot. 50 per cent of fragments (1.5 cm. long) regenerated when planted in damp soil in a warm greenhouse."

As the video continues Ms Daniels  makes this comment:-

"As soon as it dies off the horse seem to like the taste of it better, and actually eat more of it."

Let's get this straight, there is a large amount of science that shows that animals don't eat things that will damage them. The problem with is with hay and starvation abuse. Ragwort and horses  have co-evolved. The problem chemicals are in 3% of all plants. Animals are shaped by nature to avoid the fresh plant.
So that statement does not fit with what we know of the science.

Altogether I must say I am rather unimpressed with the video