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.
Saturday, 28 May 2011
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.
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.
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.
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.
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.
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.
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.
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.
The story appeared in the Western Mail and prompted this letter on ragwort in response.
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.
Postscript:
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.
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.
Postscript:
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.
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.
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.
Subscribe to:
Comments (Atom)