A video gets the law on ragwort wrong.

A wildlife enthusiast has drawn my attention to this youtube video.
It is a good video in general about a wildflower meadow being grown in an orchard.

However, at around 7 minutes 53 seconds there is this statement.

We don't want ragwort. That's poisonous. Strictly speaking it is against the law to have it on your land, because it can kill horses.

This is incorrect.

There is a previous blog entry on ragwort law, but it is most definitely not against the law to have ragwort on your land.


This is yet another example of how the propaganda on ragwort has affected people and caused them to believe false ideas.Ragwort is a valuable plant ecologically as is documented by Buglife's piece on ragwort


The problems with horses are much exaggerated.

Oh Nay! It's Emus now!

Regular followers will know that, on the basis of detailed study of the evidence, we know that ragwort poisoning of horses, cattle etc. is rare. Or to qualify that all the reliable figures that are available say it is rare. The figures around saying the contrary have no proper basis. To properly determine if ragwort causes poisoning you need to do a post mortem.

They will also know that the press, the internet etc. are full of people panicking wildly. If they so much as touch it will kill people, horses, cattle, your pet cats and dogs and even tortoises. It is nonsense of course.

If you go into any of the forums and someone starts talking about any kind of sickness with a horse, someone else will very often suggest ragwort is to blame.
If an expert goes into the forum they get shouted down and abused. Like this example of Esther Hegt the noted expert from the Netherlands.

Well the latest one made me laugh. There is now panic over emus!

OK perhaps I shouldn't laugh. Someone is only trying to be helpful and they have I have been told lost their precious much loved pets. People loosing their animal companions is no joke, but the hysteria around ragwort is.

I should also explain that people being hurt is part of my motivation for writing this blog. It isn't just ecology. People are being ripped off by people collecting money or selling dodgy cures and treatments. There is also the serious potential problem of vets getting things wrong, and there are more examples than those which I have at present written about. This leads to more animal suffering through misdiagnosis. It also makes people panic and worry about their pets when there is no need. This is harmful. The hysteria needs to be exposed for the laughable nonsense that it is.

A rather sensibly sceptical person has asked how much ragwort would kill an emu?

It seems a friend is blaming a bit of ragwort that has fallen into a water trough for killing emus. It is extremely unlikely that ragwort is the cause. I don't know how often vets do this and therefore how much information is likely to be available for comparison but the answer is to do a post mortem on the emus.

There is no simple answer to the question. I cannot find any example in the literature of an emu being poisoned by ragwort. The alkaloids in ragwort are extremely common, however since they occur in 3% of all plants. (We never hear panic about the others.) We so find, therefore, that there are records of birds being poisoned by contaminated feed from other plants.

However, we come back to the basic point. Animals of all kinds are exposed to these substances in a variety of plants and it always takes quite a bit to poison for a variety of reasons related to the way in which this works. We know from the biochemistry that a lot of the alkaloids react in ways that cause no harm so small doses will have no effect.

Stirling council misleading and damaging habitats?

You never know when an advertised example of ragwort control may be necessary. It some times is, but there are times then it is advertised and you read things and you know clearly that the people doing it should not be saying what they say.

This is the case in this example with Stirling Council who advertise a work party for the public with these words.

Doune Action Day

Ragwort flowers and Himalayan Balsam can be great for wildlife but are very invasive. Help the Rangers to pull up the plants before they seed.

If enough volunteers sign up there's plenty more work to be done.

Booking essential.

As ever the problem centres around the word "invasive" to an ecologist this is a problem non-native plant. Himalayan Balsam fits clearly in that category
Ragwort does not. It is a native plant.

It is quite likely, because other councils have done this, that the council actually thinks that ragwort, which is a valuable plant for biodiversity, isn't native either. They are certainly misleading the public on this and encouraging habitat loss by making other people think ragwort is "invasive", the word used for a foreign plant.

Another nature site being damaged

Ignorance on ragwort is rife. I would not be able to blog on this on nearly a daily basis if it were not so. It helps relieve my frustration with the nonsense and of course serves to debunk the nonsense to a wide audience.

This entry is about yet another important wildlife site being damaged.

Little Wormwood Scrubs is a piece of parkland and wilder habitat in the middle of London. It is managed by Kensington and Chelsea Council. They have a nice management plan that seems very good. It is full of excellent stuff for improving biodiversity, new hedges, wildflower meadows, everything you would expect. Then you come across this little piece.

INVASIVE PLANT CONTROL
Japanese knotweed is an invasive exotic tall herb which is present in the north
eastern corner of the site. It is recommended that this plant be eradicated before it spreads further in accordance with DEFRA advice.

Ragwort should be pulled before it sets seed and removed from site, bagged and
sent to landfill. Ragwort removal should be carried out in accordance with DEFRA
advice. Ragwort is the larval food for the Cinnebar(sic) moth, therefore allowing to grow but not set seed ensures this food source is maintained.

The terms "invasive weed" and "invasive plant" are used by ecologists to describe plants that a foreign to a country's ecology and that cause problems by spreading and replacing native vegetation. This certainly applies to Japanese Knotweed. It is a nasty pernicious invader.

Ragwort is a native plant. It has a valuable ecological role, not just for the Cinnabar Moth. It is the food of a large number of invertebrates and a nectar source for even more of them.

There is also a real piece of baffling ignorance here.
Ragwort is the larval food for the Cinnebar(sic) moth, therefore allowing to grow but not set seed ensures this food source is maintained.

You cannot maintain the plant if you do not allow it ever to set seed. It will die out! Also what about all the other invertebrates that eat it.

It may be yet another example of ignorance where council officers don't know their botany and think that ragwort is a problem invader. There is no problem with ragwort here even with the poor Defra guidelines. There are no grazing animals nor is there hay being made. There are no references in the document to this and you would not expect it in central London. ( It is only in hay that ragwort is a problem.)

There is of course the other problem. Every time this sort of misinformation is repeated more people are likely to believe it and it becomes even more prevalent.

Conservation Organisations Again

The idea for this blog post originated on Twitter. The character limit there does not help communication.

There are as I have said before a problem with UK conservation organisations being taken in by the hysterical talk. You can't really blame them. There is so much bad stuff from people like Defra and the Welsh Assembly ( who were actually issuing blatant a falsehood in a press release recently.)

In this particular exchange it was the good folks at the at a particular conservation organisation , who I have decided not to name here. They were clearing up ragwort and announced it on twitter.
Now there can be very good reasons for doing this, but there is a spate in general of conservation organisations issuing problematic information. The totality of the available evidence is that Ragwort is a problem in hay ONLY!

In this case I saw this on their website.

Ragwort pulling on this meadow Site of Importance for Nature Conservation. The meadow is in the grounds of the demolished Clifton Hostital (Sic). Ragwort is one of five injurious weeds covered by the provisions of The Weeds Act 1959. Using 'Lazy Dogs' we are going to be pulling up the ragwort before it has a chance to set seed ans (sic) spread further.


First of all, why mention the Weeds Act? I have a problem with this because you can bet the average person being told this is going to assume the Weeds Act prohibits ragwort or means you have to control it. It does not.
(It is not unheard of for conservation organisations to get this wrong.)

Mentioning the Weeds Act does not help us conservationists get our point across that the evidence says that ragwort is not the problem it has been made out to be.
(There is a posting about ragwort law here which has extra resources linked.)

Then we have the statement "before it has a chance to seed and spread further".

I have made this point before. Ragwort seed spread is not significant. We know from the research that it is normally only a few yards. If a plant grows somewhere the significant ecological factor is that the site is suitable not that the seeds arrive there. If it were then we might have ragwort growing out of the middle of undamaged paving stones, to pick and illustrative but extreme example. If the site isn't suitable the plant won't grow there.

It is maybe a little unfair just to pick on them. They may have quite honestly been mistaken.

The real problem is the poorness of the response of the conservation movement to this issue. Remember if affects lots more plants than ragwort and it has much wider effects than just a few invertebrates, as I have shown previously.

A far worse example is Dorset Wildlife Trust with this very public statement with the BBC about a very well known important invertebrate site where ragwort is an important nectar source. Even after they have been taken to task

Poisonous ragwort has to be removed as grazing is also required to maintain the open downland conditions.

Now again there may be issues with graziers who have fallen for the hysteria, but this is not what they have said. It seems that they have encouraged people to believe that if you graze an animal where ragwort grows it will be poisoned.
The evidence, and the basic biology, says that this is not the case.

I am of course aware of the Defra guidelines but from a scientific perspective, based on the evidence , they don't make sense. If you are really concerned about the welfare of animals to this degree then you would never put them outdoors.
Why? Because the level of risk of ragwort poisoning is so minuscule according to the published statistics that it is similar to that for lightning strike!

(Actually I can't find proper lightning strike statistics but there are press reports that I have researched and they show a bigger problem. It is clear that lightning strike may therefore even exceed documented ragwort poisoning. Ragwort poisoning is rare. The good statistics and the information published around the world say that.)

Isn't it about time that someone told Defra not to listen to all the daft things that are being said and be rational. I would like to see some more conservation organisations studying the science and actually doing something about the hysteria.

The good guys in this of course are Buglife who have done some excellent work on ragwort

Finally just to address a point made on twitter that there is a debate to be had.
Well if there is any debate at all. It is between those that spend time looking at the scientific journals and form their opinions that way, and those that spread false stories, either for financial gain, or because they don't think critically about things.

As a perfect example of this is someone who is now one of the best experts on ragwort in Europe, Esther Hegt, a highly intelligent horse owner who was originally a member of a ragwort extermination group. She sought out the experts who told her the hysteria spreading from the UK was rubbish and then created one of the world's finest websites on the subject. Ragwort, Myths and Facts One of the experts who has a Phd on ragwort is a major co-author.

In later postings I will cover the false information and campaigning that led to the bad guidance from Defra and the devolved equivalents.

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.

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.

IT IS COMPLETELY BONKERS! IT IS UTTER TRIPE!

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.